Olive Leaf
Olive Leaf
This information describes the common uses of Olive Leaf, how it works, and its possible side effects.

How It Works

Olive leaf extract has not been shown to prevent or treat cancer in humans.

Olive leaves contain a substance called oleuropein, which is thought to help reduce cholesterol levels. Olive leaf extracts (OLE) also reduce glucose levels in the blood. Laboratory studies found that OLE can kill a number of microorganisms including yeasts, bacteria and fungi. It was also shown to have anticancer effects. Human studies are needed.

Purported Uses

  • To prevent or treat cancer
    Laboratory results show possible benefit, but human studies have not been conducted.
  • To lower cholesterol
    Animal studies have shown a possible effect. Human studies are lacking.
  • To fight HIV
    Laboratory results show possible benefit, but human studies have not been conducted.
  • To reduce high blood pressure
    Animal and human studies show that olive leaf extract can lower blood pressure.
  • To fight infections
    Laboratory results show olive leaf extract to be effective against a variety of microorganisms.
  • To promote urination
    There is no evidence to support this claim.

Do Not Take If

  • You are taking blood pressure medicine: Olive leaf extract may increase the blood pressure lowering effect.
  • You are taking insulin or other blood sugar medicine: Olive leaf extract may cause blood sugar levels to drop too low.
  • You are undergoing chemotherapy: Olive leaf extract may interfere with the actions of certain chemotherapy drugs due to its antioxidant effects.

Side Effects

  • The pollen from olive trees can cause severe respiratory allergy.