Search Results (27)

Background/Objectives: SARS-CoV-2 infection and COVID-19 vaccination have both been linked to post-acute alopecia, yet prevalence, patterns, and correlates remain poorly defined. We aimed to determine the prevalence and patterns of alopecia after SARS-CoV-2 infection and COVID-19 vaccination, and to identify independent correlates among Saudi adults. Methods: A cross-sectional study of 1261 Saudi adults (≥18 years) was conducted nationwide between March and July 2025 using a structured, self-administered, bilingual (Arabic/English) online questionnaire distributed via social media. Eligible participants had received at least one COVID-19 vaccine dose. Data captured demographics, vaccination type and dose history, prior SARS-CoV-2 infection, self-reported alopecia subtype guided by plain-language definitions, comorbidities, and nutritional status. Hair loss and subtypes were entirely self-reported and not clinically or dermoscopically confirmed. Chi-square tests assessed univariate associations, and multivariable logistic regression identified independent predictors of any self-reported hair loss. Results: Mean age was 28.0 ± 9.6 years; 62.1% were female, 97.7% vaccinated (76.0% Pfizer-BioNTech first dose, 58.1% three doses), and 53.6% reported prior COVID-19 infection. Overall self-reported hair loss prevalence was 62.4%, with hair loss reported by 57.5% of vaccinated and 49.7% of COVID-positive participants. Self-reported telogen effluvium was the predominant pattern (56.3%), followed by androgenetic alopecia (39.3%) and alopecia areata (2.7%). Independent correlates were female sex (aOR 4.89; 95% CI 3.78–6.32), vitamin/mineral deficiency (aOR 2.31; 1.73–3.09), iron deficiency anemia (aOR 1.89; 1.29–2.78), prior SARS-CoV-2 infection (aOR 1.31; 1.02–1.68), and COVID-19 vaccination (aOR 7.45; 2.51–22.12). Conclusions: Self-reported hair loss was reported by nearly two-thirds of Saudi adults after COVID-19 vaccination or infection. Female sex and correctable nutritional deficiencies are the strongest modifiable correlates and warrant targeted screening and counseling. Full article

Background: Biotin (vitamin B7) is widely marketed and used as an over-the-counter supplement for hair, skin, and nails, despite uncertainty about its clinical benefit for alopecia and hair growth. While overt biotin deficiency can be associated with hair changes, clinically meaningful deficiency is uncommon in individuals consuming a balanced diet, and published findings on biotin status in hair loss populations are inconsistent. Methods: This is a systematic review following PRISMA. A search was conducted in PubMed/MEDLINE (PROSPERO: CRD420251274919) for human studies evaluating biotin (alone or in combination) and including hair outcomes. The synthesis was qualitative due to clinical and methodological heterogeneity. Results: Ten studies were included. Across controlled and quasi-experimental interventions, biotin monotherapy did not show consistent benefit on objective hair growth outcomes; when improvements were reported, they typically occurred in combined regimens and were difficult to attribute specifically to biotin. Studies showed mixed findings on “low” biotin levels in hair loss populations, whereas controlled studies in telogen effluvium found no significant differences in serum biotin versus controls. No serious adverse events attributable to biotin were identified; however, high-dose biotin may interfere with immunoassays, potentially leading to clinically relevant false laboratory results. Conclusions: Current evidence does not support routine biotin supplementation for alopecia in the absence of documented deficiency, although it may be considered in scenarios with risk or confirmation of deficiency/malabsorption. Full article

Androgenetic alopecia (AGA) and telogen effluvium (TE) are common hair loss disorders characterized by dysregulated hair follicle cycling and impaired dermal papilla cell function. Emerging evidence indicates that exosomes are key mediators of intercellular communication, largely through their microRNA (miRNA) cargo. Milk-derived exosomes (Mi-Exos) represent an accessible and biologically active source of regulatory miRNAs with potential relevance for hair disorders. This study evaluated the in vitro effects of bovine milk-derived exosomes (MEV-miRNAs) on human hair follicles. MEV-miRNAs were enriched in miRNA families (Let-7, miR-21, miR-30, miR-200, and miR-148/152) previously implicated in hair follicle regulation. Viability/metabolic activity of hair follicle dermal papilla (HFDP) cells was assessed, and human hair follicles were cultured ex vivo to measure shaft elongation and modulation of the WNT signaling pathway by qRT-PCR. MEV-miRNAs significantly increased HFDP cell viability after 24 h compared with controls. Human hair follicles showed a non-significant trend toward increased elongation following treatment. Gene expression analysis revealed significant up-regulation of key WNT pathway components, including WNT2, WNT5B, WNT10A, WNT11, MMP7, WISP1, and NKD1, indicating modulation of WNT-associated pathways implicated in hair follicle growth and cycling. Overall, MEV-miRNAs exhibit positive modulatory effects on signaling pathways, supporting their potential as a novel therapeutic strategy for AGA and TE. Full article

Background/Objectives: Telogen effluvium (TE) is a common, non-scarring hair loss condition characterized by excessive shedding due to disruptions in the hair growth cycle. It is often triggered by stress, hormonal changes, or nutritional deficiencies and is often associated with impaired quality of life. The objective of this study was to evaluate the efficacy and safety of a novel once-a-day drinkable food supplement in women experiencing TE. Methods: A monocentric, open-label, single-arm pilot study was conducted, enrolling 37 female subjects aged 20 to 45 years with self-perceived hair shedding and diagnosed with TE. Subjects refrained from using products with similar effects throughout the study. Evaluations included hair density, hair shedding, anagen to catagen/telogen (A:C/T) ratio, and self-perception after 1, 3, and 6 months. Statistical analyses were performed using Linear Mixed-effects Models (LMMs) and Wilcoxon signed-rank tests. Results: At 1, 3, and 6 months, a statistically significant increase in hair density compared to baseline was observed under the regimen of the tested product. After 6 months, this translated into a 12% increase vs. baseline (p < 0.001). Hair shedding decreased significantly from baseline to each subsequent visit, with a 28% reduction in shedding after 6 months (p < 0.05). The A:C/T ratio significantly increased after both 3 and 6 months, from 3.39:1 to 6.96:1 (p < 0.001). Self-perception questionnaires indicated high satisfaction with hair improvements. Conclusions: This single-arm pilot study suggests that the novel, drinkable food supplement improves hair density and hair shedding in women experiencing TE and underscores the potential of supplement intervention for managing female hair thinning, mainly by reducing TE through increased density of growing hairs. Whilst these preliminary results are encouraging, we recognize that a larger, placebo-controlled, blinded, randomized trial using the product is necessary to corroborate these findings and further explore the underlying hair cycle effects. Full article

Background: Hair loss is a common complaint, especially in the primary care setting. Despite conflicting results in previous studies regarding the role of zinc in hair loss, zinc levels are being widely tested as part of an initial laboratory investigation for hair loss. Objectives: We aimed to investigate whether lower zinc levels were associated with patients’ complaints of hair loss. Methods: In this retrospective cross-sectional study, we collected data on the zinc levels of patients diagnosed with hair loss who underwent a zinc level test after their diagnosis. The zinc levels of these patients were compared to those of a control group, which included patients who were also investigated for zinc levels for reasons other than hair loss. Results: Between 2000 and 2020, 23,975 eligible patients were included in this study. Among these patients, 9.5% (N = 2279) had a diagnosis of hair loss and a median zinc level of 96 µg/dL (84.0–110.0), compared to 99 µg/dL (85.0–115.0) in the control group (p < 0.001). Conclusions: This cross-sectional study investigated the relationship between zinc levels and complaints of hair loss. While we do report lower zinc levels in those with hair loss complaints, this change is minor and lacks clinical significance. As the standard today, we suggest that zinc levels should not be obtained as a laboratory test when investigating hair loss. Further studies on the efficacy of zinc supplements in hair loss could elucidate the clinical relevance of zinc in hair loss conditions. Full article

Research results suggest the potential of topical adenosine as a hair-promoting agent. The aim of this study was to examine the available clinical evidence of the efficacy of topical adenosine products in hair loss. This systematic review was conducted in accordance with PRISMA and PICO guidelines and included articles indexed in PubMed, Scopus, and Web of Science. The strength of evidence was assessed according to the GRADE system. Wherever feasible, data were extracted for a meta-analysis. Among 8625 articles returned by the query, 7 clinical trials were identified of topical adenosine (lotion, shampoo) in hair loss. They unanimously reported on a reduction in hair loss and increase in hair density (strength of evidence very low to moderate). A meta-analysis of three eligible trials showed a tendency to increased hair density (OR = 1.03, 95% CI: 0.89–1.20, p = 0.68), an increase in thick hair (OR = 1.4, 95% CI: 0.82–2.38, p = 0.21) and a decrease in thin hairs (OR = 0.93, 95% CI: 0.61–1.43, p = 0.75) after 6 months of alopecia treatment with a 0.75% adenosine lotion. The results from clinical trials published until now suggest that topical adenosine increases hair thickness, reduces excessive hair loss, stimulates hair regrowth, and increases hair density. The overall strength of evidence remains low due to flawed design and small sample sizes in most trials. Nevertheless, topical adenosine products seem worth trying, especially in the case of contraindications or adverse effects to approved medicinal products for hair loss. Further, better designed trials of adenosine in hair loss are warranted. Full article

Among the distressing side effects of cancer treatments, hair loss is one of the most disturbing for the quality of life and adherence to therapy in breast cancer patients. Many patients take nutritional supplements to prevent hair loss or enhance regrowth. Based on their mechanism and timing of use, nutritional supplements could be divided into safe, cautious, debated, and contraindicated categories. Non-contraindicated supplements generally include safe supplements like vitamin D, which is not known to interfere with cancer treatments. Those that are contraindicated include phytoestrogens and compounds affecting estrogen pathways because of the risk of stimulating tumor growth in cancers sensitive to estrogen. Antioxidants like tocotrienols and resveratrol are given judiciously because of potential interference with cancer therapies dependent on reactive oxygen species. Supplements debated, including nicotinamide, folate, and iron, pose a risk by promoting cellular proliferation or altering the tumor microenvironment. Biotin is nontoxic but interferes with blood test results and is thus difficult in cancer monitoring. Evidence regarding nutritional supplements’ safety and efficacy in this context is conflicting. Management by an oncologist is required along with more studies to clearly establish the safety parameters and efficacy guidelines. Full article

Botulinum toxin (BoNT) is well-recognized throughout dermatology for its cosmetic indications and growing therapeutic value. Recent studies have trialed BoNT in the treatment of hair and scalp disorders, many of which lack long-term effective treatments and significantly impact quality of life. In this review, we summarize the current clinical literature on this topic to comprehensively evaluate the efficacy, safety, and clinical value of BoNT in treating hair and scalp conditions. A literature search on PubMed/MEDLINE and Scopus identified 40 articles reporting the use of 25–200 units of BoNT-A or B in 689 patients with hair loss (79.5%), scalp seborrheic dermatitis/hyperseborrhea (10%), craniofacial hyperhidrosis (9%), folliculitis decalvans/dissecting folliculitis (0.86%), scalp pain (0.43%), or linear scleroderma (0.29%). Most studies on BoNT therapy for androgenetic alopecia (AGA) reported mild or non-significant hair growth; however, considerable variability in outcome measures complicates the ability to draw definitive conclusions or justify the use of BoNT over established AGA therapies. BoNT-A and B showed consistent efficacy in treating craniofacial hyperhidrosis with minimal side effects. Additional scalp conditions may benefit from BoNT therapy, but the evidence is limited, and larger, controlled studies are needed to better understand BoNT’s clinical value in these conditions. Full article

Alopecia encompasses diverse conditions that vary by etiology, progression, and clinical presentation, including androgenetic alopecia, alopecia areata, telogen effluvium, and scarring alopecias such as lichen planopilaris and central centrifugal cicatricial alopecia. Managing these conditions requires tailored therapeutic approaches, with topical treatments emerging as effective first-line interventions. This literature review examines topical therapies across alopecia types, assessing mechanisms of action, clinical efficacy, and safety profiles to guide evidence-based clinical practice. Methods involved a comprehensive search across PubMed, SCOPUS, and Web of Science databases, focusing on clinical research published within the past five years. Articles were screened based on relevance to alopecia management, excluding abstracts, non-English studies, and ongoing research. Topics covered include commonly used agents such as minoxidil, corticosteroids, and emerging options like Janus kinase (JAK) inhibitors. Topicals for trichotillomania, such as capsaicin and numbing creams, are highlighted for their behavioral conditioning potential, while treatments like minoxidil and adenosine are explored for telogen effluvium. Findings indicate that topicals provide symptom relief, promote hair regrowth, and often serve as adjuncts to systemic therapies. Minoxidil and corticosteroids demonstrate efficacy in multiple alopecia types, while JAK inhibitors show promise in alopecia areata. This review underscores the value of topical treatments in alopecia management and highlights areas for future research, advocating for individualized approaches to enhance therapeutic outcomes in patients experiencing hair loss. Full article

Placentae and their derivatives have been used in both traditional and modern medicine, as well as in cosmetic sciences. Although hair loss is frequently mentioned among problems for which the placenta is supposed to be a remedy, the evidence seems rather scarce. The aim of this study was to highlight the clinical evidence for the efficacy of placenta products against baldness and hair loss. Methods: This systematic review was performed according to PRISMA and PICO guidelines. Database searches were conducted in PubMed, Google Scholar and Scopus. Results: Among the 2922 articles retrieved by the query, only 3 previously published clinical trials on placental products were identified. One study was a randomized controlled trial, in which the efficacy of a bovine placenta hair tonic was found to be comparable to that of minoxidil 2% in women with androgenic alopecia. Another controlled study showed that a porcine placenta extract significantly accelerated the regrowth of shaved hair in healthy people. The third study was an uncontrolled trial of a hair shampoo and tonic containing equine placental growth factor in women with postpartum telogen effluvium with unclear and difficult-to-interpret results. Due to the design and methodology of these studies, the level of evidence as assessed with the GRADE method was low for the first study and very low for the other two. Conclusions: The very limited scientific evidence available to date appears, overall, to indicate the efficacy of placental products in both inhibiting hair loss and stimulating hair growth. Unfortunately, the number of clinical studies published to date is very limited. Further, carefully designed, randomized controlled trials of well-defined placental products are needed to definitively address the question of the value of the placenta and its derivatives in hair loss. Full article

Oligodontia can be isolated or syndromic, associated with other ectodermal abnormalities. The aim of the study was to perform hair examination in orthodontic patients diagnosed with oligodontia with a low clinical expression of symptoms of ectodermal origin. All available orthodontic patients diagnosed with oligodontia in the permanent dentition were enrolled. Hair examination included clinical evaluation of the patients’ hair, trichoscopy, trichogram and evaluation of the hair shafts under a polarized light microscope. In total, 25 patients, 18 males and 7 females, aged 6 to 24 years were evaluated for the presence of dental and hair abnormalities. The number of congenitally absent teeth ranged from 6 to 24 teeth and diastemas, microdontia, taurodontism and altered tooth shape were found in 23 patients. Hair disorders were found in 68% of the subjects. Hypotrichosis, the heterogeneity of shaft color and loss of pigment, androgenetic alopecia, telogen effluvium, trichoschisis, pili canaliculi, trichorrhexis nodosa and pseudomoniletrix were observed. Trichoscopy and trichogram are valid non-invasive diagnostic tests which could be used to differentiate between isolated and syndromic oligodontia in patients with a low clinical expression of ectodermal symptoms. Full article

Hair loss is a common clinical condition connected with serious psychological distress and reduced quality of life. Hormones play an essential role in the regulation of the hair growth cycle. This review focuses on the hormonal background of hair loss, including pathophysiology, underlying endocrine disorders, and possible treatment options for alopecia. In particular, the role of androgens, including dihydrotestosterone (DHT), testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEA), and its sulfate (DHEAS), has been studied in the context of androgenetic alopecia. Androgen excess may cause miniaturization of hair follicles (HFs) in the scalp. Moreover, hair loss may occur in the case of estrogen deficiency, appearing naturally during menopause. Also, thyroid hormones and thyroid dysfunctions are linked with the most common types of alopecia, including telogen effluvium (TE), alopecia areata (AA), and androgenetic alopecia. Particular emphasis is placed on the role of the hypothalamic–pituitary–adrenal axis hormones (corticotropin-releasing hormone, adrenocorticotropic hormone (ACTH), cortisol) in stress-induced alopecia. This article also briefly discusses hormonal therapies, including 5-alpha-reductase inhibitors (finasteride, dutasteride), spironolactone, bicalutamide, estrogens, and others. Full article

Obesity and obesity-related conditions today constitute a public health problem worldwide. Obesity is an “epidemic” chronic disorder, which is defined by the WHO as normal or excessive fat accumulation that may impair health. It is also defined for adults as a BMI that is greater than or equal to 30. The most common obesity-related diseases are type 2 diabetes mellitus, cardiovascular diseases, metabolic syndrome, chronic kidney disease, hyperlipidemia, hypertension, nonalcoholic fatty liver disease, and certain types of cancer. It has been also proven that obesity can have a negative effect on hair. It can lead to hair thinning. Patients with obesity can undergo bariatric surgery if they meet the inclusion criteria. The four common types of weight loss surgery include a duodenal switch with biliopancreatic diversion, laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, and sleeve gastrectomy. Bariatric surgery can affect skin and hair and is associated with telogen effluvium due to weight loss, microelement deficiency, anesthesia, low calorie intake, and low protein intake. Patients who undergo bariatric surgery can experience post-bariatric surgery depression. Hair loss can have a major impact on self-esteem, negatively affecting one’s self-image. The purpose of this narrative review is to critically review how obesity, obesity-related diseases, and bariatric surgery affect hair health in general and the hair development cycle, and how they influence hair loss. Full article

Astragalus membranaceus and Cinnamomum cassia are used as spices and flavorful ingredients, or medicinal herbs with pharmacological effects. In this study, the hair-growth-promoting effects of the YH complex, a newly developed formula consisting of membranaceus and C. cassia, are investigated with the prediction of its molecular mechanism. The target gene of the YH complex was about 74.8% overlapped with the gene set of ‘Hair growth’ on the GO Biological Process database. The oral administration of the YH complex promoted hair regrowth and increased hair-shaft thickness in depilated hair loss mice. In addition, the anagen/telogen hair follicle ratio was significantly increased by the YH complex. The growth factors affecting the growth of hair follicles were dose-dependently increased by treatment with the YH complex. The Wnt/β-catenin signaling pathway expressions in skin tissues were apparently increased by the administration of the YH complex. In conclusion, the YH complex consisting of A. membranaceus and C. cassia induced hair follicle differentiation and preserved the growing-anagen phase by increasing growth factors and the Wnt/β-catenin signaling pathway, leading to the restoration of hair loss. The YH complex can be a remedy for hair loss diseases, such as alopecia areata, androgenetic alopecia, telogen effluvium, and chemotherapy-induced alopecia. Full article

Telogen effluvium post-COVID-19 is a condition characterized by the diffuse and reversible loss of scalp hair in the period following infection with SARS-CoV-2, and it is currently the second cause of alopecia in women. In the context of the COVID-19 infection, intense psychological stress contributes to alopecia appearance, along with systemic inflammation, autoimmune reactions, oxidative stress, and virally induced hypoxia. Cytokines with proinflammatory action and vasoactive substances negatively modulate the metabolism of some molecules, such as proteoglycans, involved in the hair follicle’s growth cycle. Studies show that a large percentage of hairs will suddenly enter the catagen phase during a moderate to severe COVID-19 infection. In the present paper, we update the data from the literature with a clinical example. Our case highlighted that the telogen effluvium after infections with SARS-CoV-2 is reversible with appropriate dermatological treatment. For therapeutic success, informing the patient about this pathology’s self-limited and reversible character is essential to reduce the emotional stress that may aggravate the disease. Full article