Estriol (E3) is the weakest of the three major estrogens, abundant in pregnancy and used topically for skin thickness and hydration in perimenopausal women. GHK-Cu stimulates collagen gene expression and tissue remodeling. Niacinamide supports barrier function; hyaluronic acid hydrates.
Compounded estriol/GHK-Cu/niacinamide/HA creams target facial aging with lower systemic estrogen exposure than oral or patch HRT, though some absorption occurs. Popular in med-spa and telehealth longevity skin stacks paired with NAD+ face cream or injectable peptides.
Not for use in estrogen-receptor-positive breast cancer without oncology guidance. CLYR Health offers estriol + GHK-Cu cream as a preview skin SKU.