Propolis: What We Really Know About Bee Glue
Propolis turns up in throat sprays, lozenges and toothpastes in many countries. Here is what this sticky bee product is, what the studies actually show, and why it is not as harmless as its natural image suggests.
In pharmacies and health shops in many countries you will find propolis in throat sprays, lozenges, tinctures, mouthwashes and toothpastes. It is sold as a natural helper for colds and sore throats, and many people trust it because it comes from bees.
Propolis is genuinely interesting, and it has a long history of use. But the research in people is thin, and it can cause allergic reactions, sometimes strong ones. Here is a clear look at both sides.
What propolis is
Propolis is often called bee glue. Memorial Sloan Kettering describes it as a resinous mixture of pollen and beeswax that honeybees collect from the buds and sap-like exudates of certain trees and plants. Bees use it in the hive to seal holes in the honeycomb, smooth the inside walls and protect the entrance against intruders, according to a 2011 review in the Journal of Pharmacy and Bioallied Sciences.
Its make-up depends on the plants growing near the hive. The same review says the chemical composition is highly variable, which makes propolis hard to standardize. Memorial Sloan Kettering notes that its constituents vary with geographic origin. In practice, this means two propolis products can be quite different from each other, even if the labels look similar.
People have used propolis in folk medicine for a very long time, and the review traces its use back to around 300 BC. Today it is added to mouthwashes, toothpastes and lozenges, as well as sold as sprays, drops and capsules.
What the evidence says
Most of the exciting results come from lab and animal studies. Memorial Sloan Kettering says wound healing has been shown only in animals, and evidence for diabetes and heart disease is lacking. One trial for preventing colon growths found no benefit.
Studies in people are small. Memorial Sloan Kettering reports small studies suggesting possible benefit for warts, fungal foot infections and diabetic foot ulcers, and one in which a propolis and zinc solution reduced ear infections in children. Results for mouth sores caused by chemotherapy are mixed. A trial in rheumatoid arthritis found no benefit.
For colds and sore throats, the main reason most people buy it, Memorial Sloan Kettering does not report good evidence of benefit. Instead, it describes a case of a life-threatening deep neck infection that spread to the chest after someone took liquid propolis for cold symptoms. So the honest answer is that propolis has not been shown to help a cold, and it is not risk-free.
Allergy and other safety concerns
Allergy is the best known risk. Memorial Sloan Kettering calls propolis a strong sensitizing contact allergen, with reported reactions including lip swelling, redness and pain, and an itchy rash on the eyelids. The 2011 review reports that a small share of people patch-tested for dermatitis were sensitive to propolis, and that beekeepers are the most affected. Allergy can show up on the skin or as inflammation and soreness inside the mouth.
Rarer but serious problems have also been reported. Memorial Sloan Kettering describes a man who needed dialysis for sudden kidney failure after two weeks of taking propolis, and raised liver enzymes in someone who ate more than 10 propolis candies a day. Propolis can also lengthen the time it takes blood to clot, so it should not be taken with warfarin.
The review's authors conclude that propolis is not completely harmless, and that poor quality control can be a risk to health. NCCIH also advises caution with bee products in general, especially for people with pollen allergies, and notes that most supplements have not been tested in pregnant or breastfeeding women or in children.
If you still want to try it
First, check your allergies. Skip propolis completely if you are allergic to bee stings, honey, ragweed or chrysanthemums, as Memorial Sloan Kettering advises. Second, check your medicines. Do not use it if you take warfarin, and tell your doctor or pharmacist about any supplement you use.
If you want to try a propolis product on the skin or lips, test a small amount on your inner arm first and wait 48 hours. Stop at once if you notice itching, redness, swelling or soreness in the mouth. Choose a single-ingredient product from a pharmacy, use it for a short time only, and do not take large amounts. For a sore throat, plain options such as warm drinks, honey for anyone over 1 year and rest are simpler places to start.
Questions people ask
Does propolis help a sore throat or cold?
There is no good evidence that it does. Most research is from lab or animal studies, and one serious case of harm has been reported after liquid propolis was used for cold symptoms.
Is propolis safe if I am not allergic to honey?
Not necessarily. Propolis is a strong contact allergen on its own, and people can become sensitive to it over time. Test it carefully and stop if you react.
Why do propolis products vary so much?
Bees make propolis from the plants around their hive, so its chemistry changes from region to region. This is one reason it is hard to standardize.
Sources
- Propolis (About Herbs) — Memorial Sloan Kettering Cancer Center
- Is propolis safe as an alternative medicine? — Journal of Pharmacy and Bioallied Sciences (via PubMed Central)
- Seasonal Allergies at a Glance — NCCIH
This article is for general information only and is not medical advice. Herbs can interact with medicines and health conditions. Talk to a doctor or pharmacist before trying a herbal remedy, especially if you are pregnant, breastfeeding, giving it to a child, or taking any medication.
