Is Benadryl used to make illegal drugs?

Benadrylcontainsas diphenhydramine which possesses anticholinergic, antitussive, antiemetic, and sedative properties. The drug has a strong hypnotic effect and is FDA-approved as a non-prescription sleep aid, especially in the form of diphenhydramine citrate.

While it would be possible to use Benadryl in the production of methamphetamine; Benadryl is more commonly abused in its native form as opposed to being used as a precursor in the manufacture of other drugs.