Hormonal Influences on Psilocybin Responsivity Across the Female Lifespan: Toward Personalized Psychedelic-Assisted Therapy

Abstract

Today’s research highlights the therapeutic potential of the hallucinogen psilocybin in the treatment of pathologies associated with mood, cognitive, and affective dysregulation. These domains of function are regulated by the serotonergic system, which can be influenced by sex hormones, like estrogen and testosterone, and psychedelic compounds including psilocybin. Current evidence supports a higher prevalence of affective disorders in females, and a growing awareness of sex-based differences in response to drug therapy. Estrogen’s influence on serotonin physiology is an aspect that must be accounted for when planning a treatment regimen that includes a psychoactive drug such as psilocybin. A review of the current literature was conducted, and an analysis of how the fluid hormonal states in females across their different reproductive phases may impact serotonin dynamics, synaptic plasticity, and therapeutic timing of psilocybin use is discussed. Future research should focus on the influence of sex hormones on psychedelic-assisted therapy in the effort to further personalize treatment plans for these pathologies.

1. Introduction

In recent years, psilocybin, a known hallucinogen historically associated with the ingestion of specific mushrooms for ritualistic and spiritual purposes, has been reconsidered as a potential therapeutic approach for several psychiatric disorders [1]. Growing evidence from ongoing trials indicates the possible therapeutic benefits of psilocybin in the treatment of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and substance-use disorders, which are not effectively addressed by traditional treatments [2,3,4].

Based on epidemiological evidence, women are at higher risk for developing depression and PTSD [5,6]. Furthermore, although drug-abuse-cycle lengths in women are shorter than in men, they typically present with a more severe clinical profile, as well as higher resistance to achieving abstinence and increased incidence of relapse [7,8,9]. Moreover, female biological variables, particularly hormonal status, have scarcely been considered in study designs involving the treatment of these disorders [10]. This is a significant opportunity in psychiatric research and treatment, in which specific sex physiology may substantially impact treatment outcomes.

The serotonergic system constitutes a key point of interaction between physiological sex differences and psychedelic pharmacology. The modulation of the neurotransmitter 5-hydroxytryptamine (5-HT), also known as serotonin, is heavily implicated in several mood disorders, PTSD, and addiction [11,12]. Sex hormones, including estrogen and testosterone, have been shown to modulate serotonergic tone at various levels, including how the neurotransmitter is actively produced, released, and utilized across neural networks [13]. Multiple psychedelic compounds have been shown to act primarily through the serotonergic system by binding strongly to one of its receptors, 5-HT subtype 2A (5-HT2A) [14]. Due to this overlap in hormonal modulation and serotonergic function, it may be plausible that hormonal fluctuations that occur during the female reproductive phases such as puberty, pregnancy, birth and menopause or conditions such polycystic ovarian syndrome (PCOS), or amenorrhea would have notable effects on the psychotropic experience following psychedelic treatment. Few studies have, however, examined this relationship empirically.

Since hormonal dysregulation is prevalent and has significant clinical correlates in many psychiatric disorders in women, these preliminary findings underscore an urgent need for further exploration. A major gap in the literature can be identified when considering how defined hormonal states that are regulated endogenously may impact the therapeutic effects and timeline of psychedelic management for MDD, PTSD, and similar disorders. A better understanding of these determinants is crucial for the safe and effective use of psilocybin as part of a psychedelic-assisted therapeutic regimen in women.

2. Gender Disparities in Mental Health Disorders

It is evident that females are at higher risk of developing affective and stress-related psychiatric conditions. Women exhibit a consistently greater prevalence of MDD compared to men, as shown by epidemiological data representing diverse global regions [15]. Specifically in the Americas, the number of women affected by MDD is approximately double compared to men. The effects are not just limited to an increase in incidence, but an increase in the overall burden of the condition, which includes lower quality of life and premature death [16,17].

According to the Global Burden of Disease, depression accounts for at least 37.3% of reported mental health disorders, followed by anxiety and schizophrenia [18]. Females may be more vulnerable to MDD due to the complex interaction of biological (hormones, genetic risk, and physiological stress) social, and psychological factors (coping styles, personality, temperament) that cut across all ages and increase with age. Most females have low MDD incidence rates before puberty, but it increases to twice as much in males during and after puberty. Moreover, early onset of puberty has been linked to severe and long-lasting depressive disorders [17]. The CDC National Center for Health Statistics (2025) posits that a higher percentage of women than men were reported to undergo counseling or pharmacological therapy for their depression [19]. The increased vulnerability of developing anxiety and depression may be in conjunction with natural fluctuations in ovarian hormones that can change brain structure and function [20]. Anxiety disorders are determined to be the most common class of mental illness in the U.S., and

Table 1. Prevalence of anxiety disorders in male and female as taken from Global Burden of Disease (2019).

Anxiety Disorder	Prevalence in Women (%)	Prevalence in Men (%)
Panic disorder	5.0	2.0
Agoraphobia	7.0	3.5
Specific phobia	15.7	6.7
Social anxiety disorder	15.5	11.1
Generalized anxiety disorder	6.6	3.6
Posttraumatic stress disorder (PTSD)	10.4	5.0

represents the prevalence of various anxiety disorders in the population, highlighting the disparity between sexes [21].

It is established that men tend to initiate substance use more often than women, but recent findings suggest that women frequently encounter more severe consequences related to substance use, a quicker development of dependence (telescoping effect), and unique relapse patterns [7,8,9,22,23,24]. Women are more prone to relapse due to poor mood regulation or interpersonal stress, while men tend to relapse more often in positive social situations that inadvertently present high-risk situations that trigger men in recovery [25].

The development and exacerbation of affective disorders in women are frequently associated with physiological processes marked by hormonal changes, including puberty, menarche, pregnancy and delivery, and menopause [26]. These changes reflect fluctuations in sex hormones such as E2 and testosterone [27].

Standard treatments such as selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and cognitive behavioral therapy often suffer from significant limitations when used for the treatment of MDD, PTSD, and substance use disorders. These shortcomings include delayed onset of therapeutic effect, incomplete symptom remission, and a broad range of side effects such as weight gain, emotional blunting, sexual dysfunction, and sleep disturbances [28,29,30]. Thus, the need for alternative or adjunctive treatments is emphasized.

The disproportionate prevalence of affective disorders between men and women underscores the importance of considering gender differences in treatment approaches. However, research examining how psychedelic-assisted therapy affects sexes differently remains scarce.

3. Psilocybin: From Psychedelic Drug to Treatment Option

Psilocybin is a psychedelic compound found in over 180 species of mushrooms in the Psilocybe genus [31]. Four of the most widely recognized and studied species include: Psilocybe cubensis, Psilocybe semilanceata, Psilocybe cyanescens, and Psilocybe mexicana. While each species differs in psilocybin psychedelic potency, natural habitat, and morphology, these mushrooms are collectively referred to as ‘magic’ or ‘psychedelic’ mushrooms due to their consciousness and perception-altering effects. Dating as far back as the 1500s CE in Mesoamerican cultures such ‘psychedelic’ mushrooms have been used in spiritual and cultural ceremonies, as well as recreational practices [32]. The following briefly describes the four mentioned mushroom species [32,33].

• P. cubensis: Abundant in tropical and subtropical regions, it is the most widely known, cultivated, and distributed for recreational and therapeutic use.
• P. semilanceata: Found in Europe, North America, and New Zealand, this species has the highest content of psilocybin. While this is the most potent, its complex growth requirement makes its distribution challenging.
• P. cyanescens: Similarly to P. semilanceata, this species is found in temperate regions, but it thrives in urban and suburban environments. It is recognized as the one with the most abundant psychoactive content, among the listed species.
• P. mexicana: This species holds historical importance, since its first use in Aztec religious practices and the several studies, including ethnomycological, that drew continued attention since the 1950s, but it is considered one of the least potent based on psilocybin content.

Psilocybin was first isolated from P. mexicana by Albert Hofmann in 1957. Another well-known discovery by Hofmann, Lysergic acid diethylamide (LSD), had been chemically synthesized nearly twenty years prior to the finding of psilocybin. Given their commonalities as 5-HT2A agonists, investigations on LSD and psilocybin therapeutic effects were conducted in parallel. While both drugs showed similar general elate presentations and onset time in study participants, LSD was found to be a more potent drug, with longer-lasting effects and increased incidence of true hallucinations when compared to psilocybin [34,35,36].

Due to the change in mood toward elation and the lasting effects of clarity and calm reported in some of the subjects experiencing depressive symptoms, psilocybin was investigated for its potential therapeutic use in addiction, mood disorders, and depression. Because of issues associated with mass recreational use and political stigma, studies involving psilocybin were halted for a few decades. However, psychedelic-assisted psychotherapy is experiencing a revival of interest as an avenue for empirical research [34,37].

In a recent trial, psilocybin showed no significant difference in antidepressant effects when compared to a classic SSRI in patients with MDD [38]. While this trial noted limitations in its design, it is one of multiple that suggest promising clinical applications to lessen the symptoms associated with affective disorders [39,40]; speculations are supported by pilot studies to assess its possible usefulness in treating substance use disorder [41,42]. While studies on psilocybin suggest a lower addiction potential when compared to other psychedelic drugs, making this a safer and more favorable option for psychedelic-assisted psychotherapy, systematic research on long-term misuse liability remains limited and further investigation is needed to account for adverse effects [43,44].

4. Psilocybin: Mechanism of Action

Psilocybin is a naturally occurring indole alkaloid derived from N,N-dimethyltryptamine with a phosphoryloxy substituent attached at the fourth position of the indole ring (4-phosphoryloxy-N,N-dimethyltryptamine). Psilocybin can be directly extracted from psychedelic mushrooms using ultrasonic bath extraction and high-performance liquid chromatography (HPLC) [45]. This form is not directly psychoactive but rather acts as a prodrug. However, most studies examining psilocybin’s therapeutic potential utilize the synthetically derived form. The original protocol for obtaining synthetic psilocybin involved subjecting 4-hydroxyindole to a sequence of processes, including alkylation, reduction, deprotection, and phosphorylation. Still, since its original design, numerous modifications to the original protocol have been made to improve yield and scalability [46,47].

Upon ingestion, psilocybin undergoes enzymatic dephosphorylation via alkaline phosphatases, mostly within the gastrointestinal tract, kidney, and liver [48,49]. This reaction removes the phosphoryloxy substituent located at position 4 of the indole ring, converting psilocybin into its most pharmacologically active form, psilocin, or 4-hydroxy-N,N-dimethyltryptamine (Figure 1). The removal of this polar phosphate moiety significantly increases lipophilicity, which then facilitates its passive diffusion across cellular membranes and the blood–brain barrier (BBB) [48,50].

Psilocin and serotonin are structural analogs, with both compounds possessing an indole ring and a hydroxyl group [51]. However, psilocin contains a dimethylated ethylamine side chain, distinguishing it from serotonin’s primary amine (Figure 1). When comparing psilocin to serotonin, the methyl groups within psilocin’s structure reduce, making it more lipophilic and thus more permeable to the BBB relative to serotonin [50].

As psilocin crosses the BBB, it interacts with serotonin receptors [43]. The serotonin system includes over 14 G protein-coupled receptor subtypes divided into 7 families, 5-HT1 to 5-HT7, with subtypes variably expressed within the central and peripheral nervous system [52]. Of the 5-HT2 family, the subtype 5-HT2A is expressed in certain brain regions associated with cognitive function: visual cortex and thalamus, (sensory perception), prefrontal cortex (PFC) and claustrum, (self-awareness), and the cingulate, insula, and hippocampus (emotional integration) [53,54]. According to the literature, 5-HT2A may be considered a central target for psychoactive drugs and their psychedelic effects, such as altered perception, enhanced emotional sensitivity, and hallucination. Psilocin binds to 5-HT2A receptors with high affinity, acting as an agonist and eliciting conformational changes that activate Gq protein. The following intracellular cascade includes the activation of phospholipase C (PLC) enzyme, which catalyzes the formation of inositol triphosphate (IP3) and diacylglycerol (DAG). In turn, IP3 binds to the endoplasmic reticulum to release stored calcium, which acts as a second messenger to drive neuronal responses that modulate both rapid and delayed changes; the latter involving gene expression [55].

Importantly, 5-HT2A receptors have both presynaptic and postsynaptic locations. Activation of postsynaptic 5-HT2A receptors leads to neuronal excitation and increased synaptic plasticity, the core neurobiological framework of psychedelic treatments [56], whereas activation of presynaptic receptors enhances the release of glutamate, strengthening synaptic activity at sites related to cognitive functions, such as the thalamocortical synapsis, pyramidal neurons in PFC and CA1 hippocampal neurons [57]. A recent study has established that neurons lacking postsynaptic 5-HT2A receptors altogether, still show psychedelic-triggered synaptic strengthening that is mediated by the presynaptic 5-HT2A receptors [58]. Lastly, in cortical neurons, 5-HT2A receptors are primarily found intracellularly, and their activation is associated with neuronal growth. Given the reduced polarity of psilocin, when compared to serotonin, this was shown to induce dendritogenesis in rat embryonic cortical neurons by crossing the plasma membrane and activating intracellular 5-HT2A receptors. While the structural neuroplasticity induced by psilocybin and other psychedelic compounds in vitro is promising, the activation of intracellular receptors may also be involved with the hallucinogenic effects of psychedelics [56].

Despite the similarity in structure between serotonin and psilocin, which allows them to act on the same 5-HT2A receptor, functional selectivity between the two compounds may activate distinct signaling pathways. Molecular divergences, which ultimately manifest at the system level, may influence brain functional connectivity and neuroplasticity.

5. The Interplay of Sex Hormones, Serotonergic System, and Psilocin

5.1. Estrogen

Estrogen is a steroid hormone primarily associated with female reproductive physiology. Its functions include the development of female secondary sexual characteristics, the regulation of the menstrual cycle, and the maintenance of bone density and cardiovascular health. Estrogen is present in different forms: Estrone (E1), 17β-estradiol (E2), Estriol (E3), Esterol (E4), with E2 being the most active and abundant form produced naturally during a female’s reproductive years. E2 is commonly used for hormone replacement therapy (HRT) in the treatment of menopausal symptoms [59,60,61,62].

Importantly, E2 is considered a neuroactive steroid due to its interactions with serotonin, glutamate, and dopamine systems [27]. E2 exerts its functions through three different receptors: estrogen receptor α (ERα) and β (ERβ), localized intracellularly and G protein-coupled estrogen receptor (GPER); these are collectively expressed in different tissues, including the nervous system. ERβ is highly expressed in the amygdala, hippocampus and dorsal raphe nuclei, which are brain structures related to emotional regulation and memory [27,63]. Within such regions, in vivo and in vitro studies have demonstrated that ERβ is involved in serotonin synthesis by acting on tryptophan hydroxylase (TPH), the rate-limiting enzyme in the cascade for serotonin’s production [27,64,65]; E2 regulates the expression of serotonin’s precursors in the same cascade [27], and it was shown to increase 5-HT2A receptor expression in the anterior frontal cortex and claustrum, structures involved in the processing of emotion, behavior and cognition [66,67]. Furthermore, estrogen-induced changes in serotonin receptors’ density may contribute to the known emotional dynamics associated with premenstrual and postpartum periods [68,69]. Post-menopausal women treated with HRT, showed increased efficacy and availability of 5-HT2A in the PFC [70,71].

Notably, progesterone, another crucial sex hormone in the menstrual cycle, also participates in the regulation of the serotonin system by potentiating the effect of E2 on 5-HT2A expression and availability at the transcriptional level [72]. The fluctuation of E2 and progesterone has an impact on psychosocial stress and increases psychiatric vulnerability in different menstrual phases [73]. The role and characteristics of progesterone will not be detailed in this review, as this topic has been covered in a recent publication. Readers are instead directed to the comprehensive overview provided by Cohen and Blest-Hopley (2025) [74].

Interactions between psychedelics and estrogen occur via 5-HT2A and additional downstream molecular targets such as Brain-Derived Neurotrophic Factor (BDNF), and mechanistic target of rapamycin (mTOR). E2 and psilocybin have been shown to independently increase BDNF expression, a key marker for neuroplasticity, prominently within the hippocampus and PFC [74]. Similarly, mTOR, which is involved in synaptic plasticity and neurogenesis [75], has been shown to be directly activated in cortical neurons by E2 and psilocin through 5-HT2A receptor activation. Enhancing synaptic plasticity and neurogenesis have been identified as pivotal strategies for the treatment of depression [76]. BDNF expression is found to mediate the upregulation of mTOR and ameliorate depression-like symptoms in rodents, suggesting a possible synergistic antidepressant effect between E2 and psilocin via 5-HT2A [77].

Psilocin exerts its anxiolytic effect by breaking the ‘rigid rumination loops’ common in depression, anxiety and PTSD and decreases functional connectivity within the Default Mode Network (DMN) and increases overall brain connectivity [78]. These persistent and repetitive thought patterns associated with the amplification of emotion with negative valence, reduced neuroplasticity, and entropy in brain activity. Psilocin increases neural entropy by promoting crosstalk between brain regions and allowing novel associations; these are reported as a ‘brain reset’ from patients with depression. Such reorganization of brain connectivity can be observed through functional MRI (fMRI) [79,80]. Through 5-HT2A receptor activation with the internal signaling pathways involving mTOR and BDNF, psilocin promotes synaptic plasticity and assists in rewiring cognition by altering cortical gain and feedback loops [81,82].

It is plausible that, given estrogen’s role in regulating serotonin systems, the effects of psychedelic compounds like psilocin are affected by hormonal fluctuations [83]; in particular, E2 availability could influence both the effectiveness and intensity of psilocin-mediated responses, therefore modifying the outcomes of psilocybin-assisted therapy.

It is worth noting that psilocin has demonstrated binding to other serotonergic receptors, including subtypes 1A (5-HT1A) and 2C (5-HT2C), which are associated with anxiety-like behavior in rodents [84,85,86,87]. Considering the difference in signaling pathways activated through these receptors, in zebrafish, psilocin has been observed to reduce the firing of overactive serotonin neurons, exerting anxiolytic effects by way of dampening the signaling associated with fear in the amygdala, improving the brain’s control of the PFC, and by regulating stress hormones [88]. The potential anxiolytic effect of psilocin through the activation of 5-HT1A and 5-HT2C was not addressed further in this review to center the investigation around 5-HT2A.

Apart from estrogen’s effect on serotonin, the modulation of dopaminergic and glutamatergic neurotransmitters by estrogen can contribute to psychiatric conditions like schizophrenia, bipolar disorder, and MDD [89,90].

5.2. Testosterone

Testosterone is a sex hormone predominantly produced by the testes, and in much smaller quantities, by the ovaries and adrenal glands. Unlike estrogen, which presents in different forms, testosterone exists only in one form, either in a free-active state or inactive state bound to proteins such as sex hormone-binding globulin (SHBG) [91].

In addition to its role in sex differentiation, regulation, and maintenance of muscle mass and libido [91], testosterone is a potent neuroactive steroid affecting brain development and a range of sexual and social behaviors [92]. In its free-active conformation, testosterone can exert such effects through the activation of androgen receptors (AR), located primarily within their nuclei [93]. In the cerebral cortex and amygdala of male rodents, ARs have also been localized within the cytoplasm of axons, dendrites, and astrocytes (extranuclear locations), suggesting a role in modulating fast-membrane or cytoplasmic signaling processes. Such hormone-driven modulations of synaptic plasticity, cognitive function, and behavior is observed in certain neuronal populations [94]. For instance, AR-knockout mice showed exacerbated depressive-like behaviors in response to chronic mild stress, which was associated with reduced BDNF levels in murine hippocampal neurons. This suggested that AR may play a protective role against stress-induced depression by modulating BDNF expression [95].

In addition, studies in human primary neurons indicate that physiological levels of testosterone mediate a neuroprotective role directly through AR [93]. Testosterone can be converted to metabolites that act in an AR-independent manner. Specifically, testosterone can be converted to E2 via direct action of aromatase in regions including the hippocampus, amygdala, and PFC. Aromatase is found most abundantly within neurons and it has been shown to play a neuroprotective role against experimentally induced neurodegeneration in rats, due to the localized increase in E2 [96]. Notably, androgen-derived E2 has been shown to preserve neurons and neuronal synapsis in pathological or traumatic disorders. For example, E2 replacement restored neuronal integrity and hippocampal-dependent cognitive function following ischemic injury in mice [97].

Lastly, testosterone can be reduced to dihydrotestosterone (DHT) by the enzyme 5-alpha reductase and further converted into 3α-androstanediol [98]. These metabolites have been shown to reduce depression-like behaviors and inhibit oxidative stress-induced neurotoxicity and apoptosis in rodent models [99]. In agreement, the use of 5-alpha reductase inhibitors, for the treatment of prostate cancer, was associated with a higher risk of depression in men [100].

The effect of testosterone on the serotonergic system is complex but shows direct correlations to mood-modulating effects. The key mechanism of interaction between the two systems occurs via the serotonin transporter (SERT). Physiologically, SERT is responsible for serotonin clearance from the synaptic cleft and thereby reduces serotonin availability at postsynaptic receptors, and ultimately decreasing serotonergic signaling. In pathological settings, it is proposed that the upregulation of SERT may lead to an excessive reduction in the serotonin available at the synapse, which may reduce its overall connectivity, resulting in abnormal changes behind the development of MDD [101,102]. However, findings across multiple studies reveal inconsistencies with SERT, with some scholarly works reporting reduced or unchanged SERT expressions in MDD patients [103]. This may provide an explanation as to why not all patients respond favorably to SSRIs targeting SERTs. Additionally, this discrepancy may be further influenced by factors such as sex and age, which may indicate an interplay with hormonal status [104].

Testosterone is able to modulate SERT expression. Multiple studies have demonstrated that decreased testosterone levels negatively impact SERT expression, while testosterone replacement restores or enhances it. Namely, Fink et al. (1999) used a rodent model to demonstrate that testosterone, specifically its estrogenic metabolite, could increase SERT expression at both the mRNA and protein levels [105]. Similarly, Herrera-Pérez et al. 2013 found that in aging male rats, testosterone is reduced, but its restoration increased SERT expression in the dorsal raphe nucleus, which contains primarily serotonergic neurons [106]. Extending these findings to humans, Kranz et al. (2015) found increased SERT expression in several brain regions, including the amygdala and the raphe nucleus, after treating transgender males (female-to-male) with testosterone [107]. These effects however were not observed in transgender female (male-to-female) group who received estrogen and antiandrogen [107]. Such results reinforce the potential role of biological sex and hormone context in shaping serotonergic neurochemistry.

While physiological levels of circulating testosterone, or its metabolites, contribute to neuroprotection and mood regulation through ARs, given testosterone indirect influence on serotonin levels through SERT, it may be reasonable to speculate that individuals with clinically high testosterone levels may have a relative serotonergic deficit, making them more susceptible to mood disorders. By directly activating serotonin receptors, regardless of synaptic serotonin levels, psilocin may compensate for serotonergic deficiencies. In females, where testosterone participates in the regulation of the female reproductive cycle, this hypothesis becomes even more complex considering that additional fluctuating sex hormones, like estrogen described above, may influence serotonergic function and psilocin efficacy. Although theoretical and in need of empirical validation, such a model provides a framework for deeper investigation into the interplay between testosterone-driven serotonin modulation hormonal changes during reproductive stages. While psilocin requires a functional SERT to exert its behavioral effects in mice, it is not understood how excessive SERT expression due to elevated testosterone would affect psilocin’s 5-HT2A receptor agonism. Future research should evaluate psilocin application in this particular case. However, it is understood that psilocin has low affinity for SERT, making it a weak transport substrate and therefore it is hypothesized that its intended therapeutic effects may not be diminished [108,109].

6. The Potential Effects of Psilocin Across Different Reproductive Stages in Females

6.1. Puberty and Menstrual Cycle

Before puberty, the rates of depression between the sexes are similar. However, after puberty, the sex-specific pattern becomes notably disproportionate, with adolescent females becoming about twice more likely than adolescent male to experience depressive symptoms [110]. Following puberty, typical fluctuations in E2 levels during the menstrual cycle may contribute to sex-specific mood disorders susceptibility.

It is understood that the menstrual cycle is often irregular in the first few years after menarche due to ovarian hormonal control [111]. Such hormonal dysregulation in adolescents, although inherent to this phase of physical and cognitive changes (puberty), renders this population prone to developing mental health issues.

Testosterone plays a significant role to female reproductive physiology. During female puberty, testosterone levels increase and influence changes in physical development and emotional regulation [112]. Empirical studies are now beginning to highlight the link between higher testosterone levels and increased depression risk in adolescents [113]. Importantly, a study conducted on females showed that testosterone, but not E2 increase, is the sole determinant for depression in this population during puberty. Such findings are observed even when controlling for pubertal timing, which implies that the hormonal milieu itself may be driving mood susceptibility rather than just early physical development [114]. Moreover, increased testosterone in adolescent female is associated with sleep disruption and may potentially cause heightened emotional reactivity and risky behavior, all of which may ultimately affect mood [115,116]. Therefore, the evidence may support the consideration of female adolescents to be evaluate as potential candidates for psychotherapeutic use of psilocybin [117]. Drawing from the hypothesis outlined above, high levels of testosterone could lead to increased SERT expression, resulting in reduced serotonin stimulation. As an agonist, psilocin may counteract the deleterious effects of E2 fluctuation and abnormal testosterone levels to positively impact mood regulation. Historically, adolescents with MDD have been reported to misuse psilocybin, raising public health concerns of abuse and toxicity [118]. It is important to note that additional research is needed to elucidate the effects of psilocin on this critical developmental window, as much of the current data is conflicting. Findings in rodents suggest that psilocin’s effects may be age-dependent, with adolescents experiencing diminished responses compared to adults [119]. Additionally, there is limited controlled data that solidifies this specific relationship in humans. One of the few human prospective studies examined the effects of long-term psychedelic use in adolescents vs. adults through an online survey highlighting that while beneficial results were obtained by both test groups, adolescents were more likely to have negative experiences, including but not limited to fear, paranoia, and an increased prevalence of hallucinogenic persisting perceptual disorder [117].

In the luteal or ovulatory phase of the menstrual cycle, when estrogen spikes [120] and E2 increases 5-HT2A availability in cortical brain areas for the control of emotion and cognition, the same dose of psilocin could be hypothesized to have a greater response than in low-estrogen phases, when neuronal sensitivity to psilocin is reduced. While this remains to be empirically validated, it is worth noting that sex-related differences in psychedelic effects, that include 5-HT2A receptor binding sensitivity and alteration in drug metabolism have been discussed in a recent review by Shadani et al. (2024) [10]. According to studies conducted in premenopausal women with regular cycles, E2 has been shown to affect the brain’s response to psychosocial stress. Specifically, higher levels of E2 were linked to less limbic deactivation and less subjective discomfort in response to an acute stressor [73]. This suggests that periods of low E2, such as those seen in the early follicular phase and luteal phase of the menstrual cycle, may be a sign of increased vulnerability to mood disturbance. Therefore, hormonal changes that commence at puberty not only reinforce sex differences in depression risk but also lay the scientific groundwork for how cyclical hormone fluctuations affect stress response and emotion regulation throughout the reproductive lifespan.

6.2. Pregnancy and Contraception

Pregnancy and postpartum periods tend to be linked to higher depression risks [121]. Although the relationship is complex and not entirely understood, research indicates that testosterone may have an impact on depression throughout pregnancy and the postpartum period, with testosterone levels progressively increasing during pregnancy and then sharply declining after delivery. Higher levels of maternal testosterone have been associated with increased feelings of anxiety, irritability, and depression, particularly during the third trimester and in the immediate postnatal period. For instance, a study conducted in India discovered that, within 24 h of giving birth, females who experienced postpartum depression (PPD) had noticeably greater testosterone levels than those who did not report any depressive symptoms [122]. According to a different Austrian study, females who had greater testosterone levels in the final stages of their pregnancies and in the initial days after giving birth reported feeling more depressed and irritable [123].

After birth, other sex hormones, including estrogen and progesterone, normally decline [124,125,126]. If testosterone remains elevated (or drops less sharply), the relative imbalance might affect mood regulation. This, in conjunction with other risks like sleep deprivation, previously diagnosed mental health disorders and social environments and circumstances, can further exacerbate negative effects during this time frame [127]. Considering this hormonal scenario, with E2 and testosterone modulating the 5-HT2A receptor and SERT expression, respectively, psilocybin dose should be carefully monitored throughout the post-partum period and adjusted relative to these sex hormones. Of note, the transfer of psilocybin or psilocin into breast milk has not been established; therefore, it must be a consideration if treatment is planned postnatal.

While psychedelic-assisted therapy could be considered an option for pregnant women to alleviate the symptoms of affective disorders, the ethical challenges of testing psilocybin during pregnancy have resulted in very limited available clinical data. Animal studies have shown that psilocin can cross the placenta and persist longer in fetal tissues due to slow elimination [128]. Consequently, it may be reasonable to suggest that pregnant females, at any point during pregnancy, may not be eligible for psilocybin treatment due to the limited understanding of safety for both mother and child.

Of further significance, research surrounding the use of hormonal contraceptives is comparatively underexplored. Although there is evidence of mechanistic connections between the use of hormonal contraceptives (HC) and serotonergic signaling, many clinical trials examining psilocybin for mood disorders have not accounted for HC use, nor have they stratified outcomes based on hormonal status or menstrual cycle phase. Identifying literature that records both psilocybin and HC use in the context of mood dysregulation is challenging. This paucity of research may contribute to the perception of a considerable variability in both subjective psychedelic experiences and therapeutic results between study participants. Considering that HCs are widely used and affect women of reproductive age, this constitutes a major gap in research design and clinical relevance. Studies should include stratifying participants based on HC use, including the type of formulation and duration of treatment, and perform neuroimaging like fMRI, to study serotonin receptor binding and activation patterns to investigate how hormonal modulation via HC treatment alters psilocybin’s effects. Such studies have been conducted in different scenarios collecting valuable clinical data [129].

6.3. Menopause

Menopause is a crucial transition period in a female’s life marked by the termination of ovarian follicular activity and drastic alterations in sex hormones. It is an ongoing process that involves three phases: perimenopause (transition phase preceding menopause), menopause (amenorrhea for 12 consecutive months), and postmenopause (phase succeeding menopause and lasting the remainder of the woman’s lifespan). These three phases are characterized by alterations in the body’s natural sex hormones, which can profoundly impact neuropsychological function. In support of this, Jia et al. (2024) found that the prevalence of depression in perimenopausal and postmenopausal women worldwide was 33.9% and 34.9%, respectively, highlighting the pervasive emotional load during these phases [130].

During the menopausal phases, the levels of testosterone undergo a more gradual decline compared to the fluctuating levels of estrogen and progesterone, often mediated by age-related reductions in ovarian and adrenal androgen production. Growing evidence highlights a potential role of androgenic changes modulating mood seen throughout this period. In particular, higher testosterone (urinary) and a higher testosterone-to-estrogen ratio in non-depressed women were found to be associated with higher depression risk in the late perimenopausal period. Likewise, a higher total testosterone and increases in testosterone (serum) over time were associated with depressive symptoms. This correlation remained unchanged even after adjusting for menopausal status and psychosocial factors. It is worth noting that, no correlation could be made with E2 [131].

However, the literature does not always favor changes in testosterone levels over the menopausal period or an association between testosterone and depression [132]. Another study, examining basal plasma testosterone in depressed women compared to normal controls, in perimenopausal periods, found no difference between the two groups [133]. Similarly, the Melbourne Women’s Midlife Health Project showed no change in serum testosterone levels during menopause [134]. Overall, these studies suggest that monitoring temporal fluctuations in hormone ratios instead of single-point measurements may prove more accurate for predicting mood disturbances during menopause. This is especially true, given that not all females have the same hormonal shifts or experience the same stressors that may impacting mood.

During menopause, estrogen levels fall below a clinically functional threshold that is needed for reproduction and other cyclic non-reproductive processes [135]. These low estrogen levels may affect serotonergic dynamics, resulting in dysregulated mood and abnormal cognitive symptoms. Even in the context of low E2 and possibly elevated testosterone, psilocybin may remain a valuable option for psychedelic-assisted therapy, as its potency seems to not be affected by SERT activity. Regardless, considering the hormonal variability among menopausal females, current hormone levels should be scrutinized, as it continues to be an important factor when developing a treatment plan.

While HRT in females is typically associated with treating hypoestrogenism and premature ovarian insufficiency, there are other scenarios where it is indicated. These include menopause resulting from surgery (oophorectomy), PCOS, and gender-affirming care [136]. In recent findings HRT has demonstrated positive, albeit indirect, effects on cognitive functions and regulating mood disorders [137,138]. With the understanding that MDD presents both affective and cognitive symptoms, integrating HRT with emerging psychedelic therapies may provide more robust and encompassing treatment options to address the neuroendocrine and serotonergic dysregulation associated with these conditions. Currently, there are no studies that evaluate psychedelic and HRT combination therapy in females in clinically low estrogen states suffering cognitive and mood-dysregulation, which presents an opportunity in research to understand ways to potentially treat these patients in a more comprehensive manner. It must be stressed that this will involve not just females in menopause, but all those who stand to benefit from HRT for all the conditions mentioned earlier.

Despite the renewed interest in psychedelic therapies and the known establishment of hormonal impacts on brain functioning, research in this area remains surprisingly scarce. One of the scant studies published on this subject is a case series of three women reporting changes in their menstrual cycles after using psychedelics such as psilocybin and LSD [126]. The documented experiences in this case series included menstrual return following amenorrhea, early menstruation when psychedelics were administered in the luteal phase, and increased regularity of menstrual cycles in a case of PCOS. These changes may indicate an involvement between psychedelics and the hypothalamic-pituitary-gonadal (HPG) axis, which is associated with the regulation of reproductive hormones.

Additionally, insight into how psilocybin microdosing affects female diagnosed with premenstrual dysphoric disorder, a severe form of premenstrual syndrome, is currently being developed. The preliminary investigation highlights self-reporting from participants claiming to experience effective regulation, decreased physical symptoms, and an improved overall quality of life when microdosing psilocybin throughout the premenstrual cycle [139]. However, due to the self-reporting nature of experimental evidence, these findings are not yet definitive. These self-reported outcomes point toward possible therapeutic potential, though more rigorous studies are needed to validate efficacy and safety. Recent literature suggests that a direct relationship between psilocin and estrogens may exist, affecting these hormone states outside of the influence of serotonin. Although this relationship is relevant to this paper’s topic, it will not be discussed here due to the limited and inconclusive evidence available in the current literature.

While future research will be required to fully explicate the relevant dynamics, psilocin’s activity may potentially be bound to the hormonal context in which it is applied.

Table 2. Hormonal changes and their effect on mood changes in females from puberty through the reproductive cycle, pregnancy, and postpartum.

Stages of Development	Hormonal Changes	Mood Changes	References
Puberty	Fluctuations in E2 Increase in Testosterone	Risk for depression.	[113,140]
Menstrual	Decrease in estrogen and progesterone levels Increased testosterone (especially during the ovulatory phase)	Increased risk for depression.	[120,141,142]
Pregnancy	Increased estrogen and progesterone levels Increased testosterone	E2 and progesterone are protective against severe depression. Elevated testosterone linked to increased risk for depression.	[123,143,144,145]
Postpartum	Deficiency in estrogen and progesterone levels Decrease in testosterone	Lower E2 and progesterone causes an increased risk for depression/psychiatric disorders. If testosterone increases, then possibility of depression.	[122,123,124,125,126]
Menopausal	Decline in ovarian estradiol production Gradual decline in testosterone	Mood swings If testosterone increases then possibility of depression	[131,146]
Perimenopausal	Decline in progesterone levels, Estrogen deficiency (mostly) Gradual decline in testosterone	Depressive symptoms, sleep disruption. If testosterone increases then greater risk for depression.	[124,125,147,148]
Postmenopausal	Estrogen shifts from estradiol to estrone. Testosterone low and stable	Increased risk for depression. Weak/Absent link between testosterone and depression.	[124,132,147]

summarizes the concept described above, regarding the hormonal changes at various reproductive stages in females, from puberty to post-menopause, and associated mood changes.

7. Conclusions and Future Directions

Though its first appearance showed psilocybin as a tool for healing and culturally unique experiences in centuries-old ceremonies and rituals, the contemporary view based on active clinical trials is that it is considered one of the most promising substances in treating disorders such as depression, anxiety, PTSD, and addiction [1,38,39,40]. Psilocin’s effects on anxiety and depressive symptoms appear to originate from a break in the rigid rumination loops of the DMN, thereby increasing neural plasticity, entropy, and communication that enhance cognitive function and ultimately lead to a subjective recalibration of mood states, as evidenced by fMRI studies [79,149]. These are mediated by the serotonergic receptors, which become one of the major points of intersection between sex hormones and psilocin [27,55,69,72,150,151].

While much progress has been made in revealing the crosstalk between sex hormones, psychedelic therapies, the serotonergic system, and affective disorders, important gaps in research remain. The synergistic effects of psilocin and sex hormones on the serotonergic system could potentially affect the outcomes of psychedelic-assisted treatment. The current literature supports that psilocybin is a hopeful candidate for the treatment of mood dysregulation pathologies, but its effects in female patients may be moderated by the dynamics of estrogen and testosterone fluctuations over their lifespan.

Integrating the measurement of these sex hormones across various hormonal stages into study design, as well as clinical practice, may advance the understanding of the mechanisms of psilocybin and further improve its therapeutic potential. Future research should prioritize sex-specific, and hormone-guided approaches to better understand how sex hormone status associates with psychedelic therapy, which will drive the evolution of personalized treatment.