Propolis is a very complex substance used by bees to control the environment of the nest. Bees collect sap from trees containing plant phenols and bioflavonoids.

The actual constituent parts vary according to climate and plants visited by the bees.

They collect these plant products and carry them home in their corbiculae.

Guidance will follow to describe how to extract propolis for topical use.
Scientific Beekeeping
Leinster Honey
This article produced in Bee Culture gives a clear understanding of the background of Propolis: PROCESSING PROPOLIS: PART I
Part 2 from Bee Culture goes on to make claims which are yet to be backed upon by serious double blind scientifically performed research. I place the link here for interest: PROCESSING PROPOLIS: PART II