It may be used as a supposed remedy for psoriasis and eczema; in aftershave and ingrown nail applications, to prevent dehydration of skin; and for insect bites and poison ivy. Clinical studies supporting its effectiveness for these skin conditions are absent. Despite this lack of evidence, it is used in folk medicine to "ease discomfort" involving vaginal soreness and hemorrhoids while they heal after childbirth. There is no good clinical evidence for its other purported traditional uses, including gastrointestinal illnesses (diarrhea), common colds, tuberculosis, and inflammation. Distilled witch-hazel water does not contain the tannic acid found in Hamamelis bark, and does not have the therapeutic attributes often claimed for it.
The leaves and bark of the North American witch-hazel, Hamamelis virginiana, may be used to produce an astringent decoction as a cooling agent for various uses in traditional medicine, herbalism, and skincare products. This decoction was widely used for medicinal purposes by Native Americans and is typically sold in modern pharmacies as witch-hazel water and as semisolid ointments, creams, gels, and salves. It is commonly used to treat diaper rash in infants. Witch-hazel water can be produced by maceration and by distillation. As an ingredient and as topical agent, witch hazel water is regulated in the United States as an over-the-counter drug for external use only to soothe minor skin irritations.
The main constituents of witch-hazel extract include calcium oxalate, gallotannins, safrole, and chemicals found in the essential oil (carvacrol, eugenol). Witch hazel is mainly used externally on hemorrhoids, minor bleeding, and skin irritation
Studies have not showed the side-effect.