Witch HazelvsZinc Oxide

Hamamelitannin (a gallotannin) and polyphenols cross-link and precipitate stratum corneum proteins via hydrogen bonding and hydrophobic interactions, temporarily tightening skin surface, reducing pore appearance, creating matte finish by binding sebum. Tannins inhibit 5-lipoxygenase (reducing leukotriene B4) and scavenge reactive oxygen species. Gallic acid, catechins, proanthocyanidins provide antioxidant protection. Hamamelitannin inhibits elastase, potentially protecting elastin. Astringent effect temporary (hours) — does not alter pore size or sebum production long-term. Alcohol-free witch hazel (distillate or hydrosol) preserves benefits; alcohol formulations add drying and barrier-disrupting effects. Polyphenols may have mild vasoconstrictive effects, reducing erythema.

Zinc oxide particles sit on the skin surface and primarily scatter and reflect UV radiation across the full UVA (320–400 nm) and UVB (280–320 nm) spectrum via Rayleigh and Mie scattering. At nano scale, zinc oxide also absorbs UV photons and undergoes semiconductor band-gap excitation, converting UV energy to heat—a mechanism similar to organic chemical filters. It provides the broadest single-ingredient UV coverage available. Beyond photoprotection, zinc oxide exerts anti-inflammatory effects by inhibiting NF-κB activation, reducing pro-inflammatory cytokine release (TNF-α, IL-6), and modulating Toll-like receptor signaling. It supports barrier repair by promoting occludin and zonula occludens-1 expression in tight junctions. Zinc ions have mild antimicrobial activity against Staphylococcus aureus and Candida species. These properties underlie its use in diaper rash creams, wound care, and post-procedure skincare. Zinc oxide does not penetrate intact stratum corneum when formulated as micronized or nano particles.