Neurocosmetics and Aromatherapy Through Neurocutaneous Receptors and Their Functional Implications in Cosmetics

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Well organized document and overall reviews aspects of neurocosmetics. It would have been interesting to have had a section on finished product and claims used to achieve a neurocosmetic claim. 

Author Response

Comment: Well organized document and overall reviews aspects of neurocosmetics. It would have been interesting to have had a section on finished product and claims used to achieve a neurocosmetic claim. 

Response: We appreciate the reviewer’s observation. We agree on the relevance of including a section on the final product and the claims that substantiate a neurocosmetic assertion. However, in this review we chose to limit the scope to biological mechanisms and ingredient-level evidence. Our group is currently working on the formulation of blends of neurocosmetic actives, and we prefer not to pre-empt results or claims while we complete the physicochemical, safety, and efficacy evaluations. Our goal is to present that applied component in a subsequent manuscript once we have complete and verifiable data.

Reviewer 2 Report

Comments and Suggestions for Authors

• The phrase "Challenges of neurocosmetics and Essencial oil" contains a typographical error in the word "Essencial." The correct spelling in academic English is "essential."

• The manuscript should define the term "neurocosmetics" clearly at the beginning.

• It should explain related expressions such as "neurocosmetic actives" and "neurocosmetic formulations" to avoid confusion.

• A brief glossary or summary of key terms for clarity should be included.

• Consistent use of terminology should be ensured throughout the manuscript to maintain coherence.

Author Response

We appreciate the reviewer’s observation.

Comment: The phrase "Challenges of neurocosmetics and Essencial oil" contains a typographical error in the word "Essencial." The correct spelling in academic English is "essential."

Response: Changes in the manuscript. The heading was corrected to “Challenges of Neurocosmetics and essential oils”, and the usage of “essential oil(s)” was standardized throughout the text

Comment: The manuscript should define the term "neurocosmetics" clearly at the beginning.

Response: Done. We added a clear definition at the start of the Introduction.

Comment: It should explain related expressions such as "neurocosmetic actives" and "neurocosmetic formulations" to avoid confusion.

A brief glossary or summary of key terms for clarity should be included.

Consistent use of terminology should be ensured throughout the manuscript to maintain coherence.

Response: Agreed and implemented. To facilitate clarity, we added a concise glossary and opted to present it as a table highlighting the definitions we consider essential for the field.

Reviewer 3 Report

Comments and Suggestions for Authors

Your review reveals the positive effects of essential oils, but certain essential oils can also cause respiratory and skin allergies. These aspects should also be added and related to concentration of oils in formulation.

At line 321 table I replace with Table 2.

Line 451  Essencial -  Essential 

Author Response

Comment: “Your review highlights positive effects of essential oils, but certain essential oils can also cause respiratory and skin allergies. These aspects should be added and related to the concentration of oils in the formulation.”

Response. We appreciate the reviewer’s observation. In Section 1.5 — Challenges of Neurocosmetics and Essential Oils, we expanded the safety/tolerability discussion to address respiratory sensitization and allergic contact dermatitis associated with essential oils, explicitly emphasizing the concentration-dependent nature of these risks and the need to adhere to safe dermal levels and recognized safety monographs. We also highlight cumulative exposure, photosensitization risks in leave-on applications (notably for furocoumarin-containing citrus oils), and the value of developmental patch testing, oxidation control (e.g., limiting peroxides in linalool/limonene), and transparent allergen labeling. To support these additions, we incorporated three references (now cited as [223–225]).

Inserted text (Section 1.5; Track Changes visible).From a safety standpoint, essential oils can elicit concentration-dependent respiratory sensitization and allergic contact dermatitis in susceptible individuals. These risks may be compounded by cumulative exposure and, in the case of furocoumarin-containing citrus oils, by photosensitization—particularly in leave-on formulations. Accordingly, products should comply with published dermal limits and recognized safety monographs, incorporate stability controls to minimize oxidation of sensitizing constituents, and include patch testing during development with transparent labeling of potential allergens. Although fatal outcomes from dermal absorption have not been documented to date, cases of non-fatal systemic toxicity have been reported. The most common adverse effects are photosensitization and contact dermatitis. Given the uncertain true incidence and the wide variability in published estimates, essential oils should be used within safe concentration ranges and with prudent exposure management [223–225].

Comment: At line 321 table I replace with Table 2.

Response: Table renumbering: “Table I” → “Table 2” (previously around line 321). Done

Comment. Line 451  Essencial -  Essential 

Response: “Essencial” → “Essential” (previously around line 451). Done