Evidence & Source Library
This site is an affiliate publication, so source discipline matters. We separate merchant claims from independent medical/regulatory context and link to authoritative references when that improves verification.
Core medical and regulatory sources
American Academy of Dermatology
Used for signs, diagnosis, treatment categories, regrowth timelines and why nail conditions can be confused with one another.
FDA OTC Monograph M005
Used for the regulatory context around topical antifungal actives such as undecylenic acid and the explicit “not effective on nails” direction for monograph skin antifungals.
FDA Nail Care Products
Used to distinguish cosmetic nail products from products intended to treat disease.
Commercial product sources
For Kerassentials we reviewed the current merchant text presentation supplied through the user's affiliate research link on September 28, 2026. For competitor comparison pages we reviewed current public product pages for ProNail Complex, Kerafen, Nail Refresh and Kerasal. We do not reproduce competitor purchase links because the site is monetized around Kerassentials and the comparisons can be explained without directing users to unrelated checkouts.
What we do not treat as proof
- Testimonials or before/after images without controlled evidence
- Ingredient studies as proof of the finished product
- “Doctor formulated,” “natural,” “GMP,” or “made in the USA” as proof of effectiveness
- A refund guarantee as proof of clinical results
- Facility registration language as equivalent to FDA approval of a product
Last reviewed: September 28, 2026
