[G Larry]

That is NOT the definition of a "controlled substance" under the law.
Do some homework!

[Ostlandr]

While the dictionary definition

http://www.wordwebonline.com/en/CONTROLLEDSUBSTANCE

would seem to include perscription medications, sildenafil citrate does not in fact appear in the DEA schedules of controlled substances.

http://www.deadiversion.usdoj.gov/schedules/index.html

I stand corrected