Bee propolis

Propolis is a resinous material collected by bees from the buds or other parts of plants. It is known for its biological properties, having antibacterial, antifungal and healing properties.

In latest researches, Bee Propolis has shown antifungal activity on various Candida.
Candida albicans strains were collected from HIV-positive patients with oral candidiasis. The research studied the inhibitory [...]

In general, propolis is safe to use. It is a non-toxic substance and will not cause irritation for most people.
However, like with other honey bee products, there are some people who are allergic to propolis.
You may be one of them if you are:

allergic to any bee product (pollen, honey, royal jelly),
allergic to bee stings,
an asthma [...]