D-mannose is a simple sugar found in many fruits. It is related to glucose. It also occurs naturally in some cells in the human body.
Other names for D-mannose are:
Applying witch hazel to the skin is the most common way it is used -- and the safest.
People sometimes take witch hazel by mouth. When taken that way it is used to try to treat conditions as varied as:
Vomiting or coughing up blood
Colds and fevers
Witch hazel may bring some relief from hemorrhoids or skin irritations and lessen minor bleeding. Witch hazel extracts contain antioxidant compounds that may protect against sunburn and aging from the sun.
But the evidence is thin on its use for other conditions. Researchers have more work to do to demonstrate its effectiveness.
These are typical dosages of witch hazel:
By mouth: 2 grams of dried leaves three times daily or as a tea.
On the skin: 5 to 10 grams of leaf and bark simmered in 250 milliliters of water or undiluted.
As an alcohol extract (commonly available in pharmacies): Saturate a piece of cloth and apply to the affected area.
Rectal area. By suppository, use 0.1 to 1 gram leaf and bark applied one to three times daily. When applied to anal area, witch hazel water may be applied up to six times a day or after bowel movements.
Can you get witch hazel naturally from foods?
Witch hazel is not found naturally in foods.
What are the risks of taking witch hazel?
Witch hazel is relatively safe.
Side effects. Stomach upset may result from taking witch hazel by mouth. When you apply it to skin, it may, rarely, cause inflammation (contact dermatitis). But even children tend to tolerate it well on the skin.
Risks. If you use witch hazel in appropriate amounts, your risks are relatively minor. But if you take high doses by mouth, it may cause kidney or liver damage.
Although witch hazel contains a known cancer-causing ingredient, there's likely no need for concern. The amounts are very small.
Because studies are limited, avoid using witch hazel if you are pregnant or breastfeeding, unless you use it on the skin in small amounts and for short periods of time.
Interactions. There aren't any known interactions with drugs, foods, or other herbs and supplements.
The FDA does not regulate supplements. Be sure to tell your doctor about any supplements you're taking, even if they're natural. That way, your doctor can check on any potential side effects or interactions with medications, foods, or other herbs and supplements. He or she can let you know if the supplement might raise your risks.