Beauty analyzes products at the level of the formula: active ingredient, concentration, delivery system and the evidence supporting each claim. Coverage spans skincare, sun protection, hair treatment and in-clinic procedures, with realistic timelines for visible change and clear notes on when a dermatologist is the better purchase.
Skincare and haircare examined by formulation: which actives work at which concentrations, how long results take, and where topical treatment stops.
The 600-IU baseline survived a decade of challenges; the Endocrine Society's 2024 guideline and the VITAL trial rewrote the case for testing and for high doses.
Written by Sarah Collins
Citrate, glycinate, oxide — the label chemistry decoded, with the absorption studies behind the rankings and the claims that outpace them.
Written by Sarah Collins