propolis

Propolis is a resinous material that honeybees produce by combining plant resins and saps with beeswax and pollen, then use to seal and protect the hive. It is marketed as a dietary supplement in forms such as capsules, tinctures, extracts, lozenges, and topical products. Its chemical composition varies considerably depending on the plant sources the bees foraged from, so no two products are necessarily alike.

Evidence in people is limited. Memorial Sloan Kettering's About Herbs resource notes that laboratory and animal research points to possible antimicrobial, anti-inflammatory, and antioxidant activity, but states that "data in humans are limited" and that propolis has not been shown to treat the conditions it is marketed for. A few small human trials have suggested possible benefit for warts and for fungal foot infections; its effect on mouth sores caused by chemotherapy (mucositis) is described as equivocal. In a study of supplemental propolis for colon-cancer prevention in higher-risk patients, it was not helpful and showed signs of possible harm. None of this rises to the level of established efficacy, and more rigorous human studies would be needed before any therapeutic claim could be made.

There is no established or standardized supplement dose for propolis, and product strength is inconsistent because its composition differs from hive to hive. Dietary supplements are not tested by the FDA to confirm that the contents match the label, so quality and potency can vary between products. Talk to a clinician before using propolis, particularly if you have a health condition, take medications, or are pregnant or breastfeeding.

Avoid propolis if you are allergic to bees or bee stings, honey, ragweed, or chrysanthemum. NCCIH warns that people with pollen allergies may have allergic reactions to bee products, including propolis. Published case reports have linked propolis or bee-pollen use to serious harms, including severe allergic reactions, photosensitivity, acute kidney failure requiring dialysis, and elevated liver enzymes. Use caution and stop using it if any reaction occurs.

The most commonly reported problems are allergic and skin reactions, such as contact dermatitis, irritation around the mouth, lip swelling, and photosensitivity (increased sensitivity to sunlight). More serious reactions have appeared in case reports. Seek prompt medical care for trouble breathing, severe swelling, or other signs of a systemic allergic reaction.

Propolis and bee pollen may interact with the blood thinner warfarin. A published case report described a probable interaction with honeybee pollen that raised the INR, a measure of how long blood takes to clot. People taking warfarin or other anticoagulants should avoid propolis unless their clinician approves.