One 2020 study in the journal Phytotherapy Research argues that propolis’s antiviral properties may mean that it works against SARS-CoV-2. This is the coronavirus that causes COVID-19. According to one small study in the review, propolis significantly decreased the amount of bacteria in the saliva of people with periodontitis. Inflammation Dumitrescu, M., Crisan, I., and Esanu, V. [The mechanism of the antiherpetic action of an aqueous propolis extract. II. The action of the lectins of an aqueous propolis extract]. Rev Roum.Virol. 1993;44(1-2):49-54. View abstract.

When applied to the skin: Propolis is possibly safe when used appropriately. It can cause allergic reactions, especially in people who are allergic to other bee products. Pregnancy: There isn't enough reliable information to know if propolis is safe to use when pregnant. Stay on the safe side and avoid use. Bruyère F, Azzouzi AR, Lavigne JP, et al. A multicenter, randomized, placebo-controlled study evaluating the efficacy of a combination of propolis and cranberry (Vaccinium macrocarpon) (DUAB®) in preventing low urinary tract infection recurrence in women complaining of recurrent cystitis. Urol Int 2019;103(1):41-8. View abstract. Hashimoto T, Tori M, Asakawa Y, Wollenweber E. Synthesis of two allergenic constituents of propolis and poplar bud excretion. Z Naturforsch [C] 1988;43:470-2. View abstract. Researchers had a hunch that propolis could decrease TH and in turn, lower blood pressure. So they took a bunch of rats and fed them something called nitro-l-arginine methyl ester for 15 days, to produce high blood pressure. They then fed the rats propolis for the last five days.Scientists recently decided to look at the anti-cancer and anti-microbial potential of propolis at the same time. One study investigated the anti-bacterial capabilities of bee propolis in the mouth and more specifically with regards to root canals. Brumfitt, W., Hamilton-Miller, J. M., and Franklin, I. Antibiotic activity of natural products: 1. Propolis. Microbios 1990;62(250):19-22. View abstract. Bezuglyi, B. S. [Effect of the Propomix preparation on corneal regeneration]. Oftalmol.Zh. 1980;35(1):48-52. View abstract. Hoheisel O. The effects of Herstat (3% propolis ointment ACF ) application in cold sores: a double-blind placebo-controlled clinical trial. Journal of Clinical Research 2001;4:65-75.

Terpenoid: esters of long-chain fatty acids, (3-hydroxystearic acid ( n = 11) procrim a; 3-hydroxystearic acid ( n = 13), procrim b and a pentacyclic triterpenoid (lupeol))

Viuda-Martos M, Ruiz-Navajas Y, Fernández-López J, Pérez-Alvarez JA. Functional properties of honey, propolis, and royal jelly. J Food Sci. 2008;73(9):R117-R124. doi:10.1111/j.1750-3841.2008.00966.x

Another 2021 review found that propolis may also help treat mouth and throat infections, as well as dental caries (cavities). Here, researchers suggest that the product’s antibacterial and anti-inflammatory effects could potentially play a role in overall oral health care. CancerReported in the International Journal of Dermatology in November of 2009, scientists found that propolis shows strong activity against warts.