Commonly used plant extract that can have potent antioxidant properties (Sources: Phytotherapy Research, June 2002, pages 364–367; and Journal of Dermatological Science, July 1995, pages 25–34) and some anti-irritant properties (Source: Skin Pharmacology and Applied Skin Physiology, March-April 2002, pages 125–132).
However, witch hazel’s high tannin content (and tannin is a potent antioxidant), can also be irritating when used repeatedly on skin because it constricts blood flow. The bark of the witch hazel plant has higher tannin content than the leaves. Steam distillation for producing witch hazel water removes the tannins, but the plant’s astringent qualities are what most believe give it benefit. Alcohol is added during the distillation process, the amount typically being 14–15%. Witch hazel water is distilled from all parts of the plant, so in that sense you never know what you’re getting, though the alcohol content remains (Source: www.naturaldatabase.com; www.drugs.com). Depending on the form of witch hazel, you’re either exposing skin to an irritating amount of alcohol (which causes free radical damage and collagen breakdown), tannins, or both. Moreover, witch hazel contains the fragrance chemical eugenol, which is another source of irritation (Source: International Journal of Trichology, July-September 2014, pages 100-103).