Witch Hazel Worst Irritant Oil Control Witch Hazel at a glance Commonly used plant extract from the Hamamelis virginiana shrub Can have potent astringent, anti-irritant, and skin soothing properties Its high tannin content can also make it sensitizing to skin Can be derived from different parts of the plant Witch Hazel description Commonly used plant extract that can have potent antioxidant properties and some soothing properties. However, witch hazel’s high tannin content (tannin is a potent antioxidant) can also make it sensitising if used repeatedly on skin because it denatures proteins that help keep skin healthy. The bark of the witch hazel plant has a higher tannin content than the leaves, which contain other compounds, including beneficial antioxidants. Producing witch hazel water by steam distillation removes the tannins and can circumvent the need to use skin-damaging alcohol (ethanol), but the plant’s astringent qualities are what most believe give it benefit. But using water or steam distillation rather than alcohol is one way to obtain a gentler form of this ingredient for occasional use; it just doesn’t make witch hazel problem-free, so we don’t advise using it on skin often. Alcohol added during the distillation process is typically used in amounts of 14-15%. That’s more than enough to damage skin, as research has shown amounts as low as 2% can harm skin cells. Witch hazel water is distilled from all parts of the plant; therefore, you never know exactly what you’re getting, although the alcohol content remains since this form of witch hazel either uses alcohol during distillation or it is added afterward to enhance penetration of the witch hazel water. Summing up, depending on the form of witch hazel, you’re exposing your skin either to a sensitising amount of alcohol or to tannins, or both. Moreover, witch hazel contains the fragrance chemical eugenol, which is another source of sensitivity. For a deeper dive into the research on witch hazel, see our in-depth analysis here. Related ingredients: Hamamelis Virginiana Hamamelitannin