Diagnostic Comparison: SH‑1 Molecule vs PP405 — Safety Profiles in Hair Science

June 2026 in “ HAL (Le Centre pour la Communication Scientifique Directe) ”

Melvin Sewell

TLDR SH‑1 is safer for cosmetic use than PP405.

The document compares the safety profiles of two hair-science molecules: SH‑1, a cosmetic active ingredient, and PP405, an investigational drug candidate. SH‑1 shows zero systemic absorption and maintains epidermal barrier integrity at all dose levels, indicating a strong safety profile for cosmetic use. In contrast, PP405 exhibits dose-dependent systemic uptake, with dermal infiltration and a breach of critical safety thresholds at therapeutic concentrations, highlighting potential risks. This comparison underscores the differences in safety and regulatory considerations between cosmetic and investigational molecules in hair science.

View this study on hal.science →

Discuss this study in the Community →

Related Community Posts Join

6 / 1000+ results

community PP405 will be available on Everychem soon apparently

in Research/Science 99 upvotes 1 year ago

PP405 is a potential hair loss treatment, but its safety and effectiveness are uncertain. Users advise caution and suggest waiting for more data before purchasing unverified versions.

community If PP405 goes systemic this would be quite catastrophic

in Research/Science 4 upvotes 1 year ago

Concerns about the potential systemic effects and safety of PP405 for hair loss, with discussions on its comparison to existing treatments like finasteride and minoxidil. Users express skepticism about untested research chemicals and emphasize the importance of clinical trials to ensure safety and efficacy.

community Don't use PP405 from everychem. it is likely fake.

in Research/Science 66 upvotes 1 year ago

PP405 from Everychem is likely fake and potentially harmful, with concerns about its stability and the risk of using the wrong MPC inhibitor, which could damage hair follicles. The real PP405 was studied under strict conditions, and DIY attempts are discouraged due to unknown formulation and quality control.

community PP405 (Everychem 3HP) users - assemble and share your updates!!

in Chat 44 upvotes 3 months ago

Users discussed experiences with Everychem's solution similar to PP405 for hair loss, noting some positive results like increased hair thickness and new growth. There was skepticism about the product's legitimacy and safety, with some users reporting early signs of effectiveness and others expressing concerns about the lack of evidence and safety profiles.

community PP405 (Everychem 3HP) Users - Assemble and share your story!

in Chat 19 upvotes 2 months ago

Users discussed the effectiveness of Everychem's solution, similar to PP405, with some reporting improved hair thickness and new growth. Concerns were raised about safety and the legitimacy of the product, with some users advising against purchasing research chemicals.

community PP405 Hair Loss Drug: Phase 1 Human Results & Biopsy Insights

in Research/Science 215 upvotes 1 year ago

PP405 is a potential hair loss treatment undergoing trials, with discussions on its effectiveness and comparison to existing treatments like finasteride and minoxidil. There is skepticism about its status as a cure, with hopes for future advancements in genetic treatments like CRISPR.

Similar Research

5 / 1000+ results

research LB1045 Inhibition of pyruvate oxidation activates human hair follicle stem cells ex vivo

July 2024 in “Journal of Investigative Dermatology”

PP405 may help hair growth by activating hair follicle stem cells.

research PP405 in Alopecia: An Emerging Molecule worth Investigating

January 2026 in “Journal of Community Medicine and Health Solutions”

PP405 shows promise as a new, effective treatment for hair loss with minimal side effects.

research Detection of polysulfide species in human hair cuticle and protective effect of sulfur donor on heat induced-damage of hair

February 2020 in “The Pharmaceutical Society of Japan”

research Chemical Safety and Technical Decision-Making in Hair Procedures: A Professional and Scientific Perspective

February 2025 in “Zenodo (CERN European Organization for Nuclear Research)”

Proper training and scientific knowledge are crucial for safe and effective chemical hair procedures.

research Chemical Safety and Technical Decision-Making in Hair Procedures: A Professional and Scientific Perspective

February 2025 in “Zenodo (CERN European Organization for Nuclear Research)”

Scientific knowledge is crucial for safe and effective chemical hair procedures.