It kills the bacterium Porpionibacterium acnes that
causes acne pimples.
It has an anti-inflammatory effect that reduces pimples and
the pain they cause.
It is a bleaching agent, oxidizing dyes to make them colorless.
It eliminates fatty acids on the skin.
A peroxide is a compound that has an oxygen-oxygen bond.
That is, it has two oxygen atoms bound together.
Look at the structural formula at the top of the page.
The molecule is symmetrical, with two identical parts joined
at their oxygen atoms with an oxygen-oxygen bond.
A familiar peroxide is
It has two oxygen atoms bound together, and each of those
atoms in turn it bound to a hydrogen atom.
Peroxides make good bleaches. The oxygen atoms combine with
dyes to make the dyes colorless. This process (called oxidation)
can kill germs.