Well, he's fictional, so there's no way to "know" anything about him that's not indicated in the movie. For example: did he play Little League as a kid, and what position(s)?
If I had to say, though, I'd say no, based on two different analyses -

• The extent to which it was consistent with what we did know of him, and of the time in which he lived: He was bit on the old side for the age group with the highest rate of usage. In that era, those who did use tended to go overboard pretty quickly, unless they were restrained by circumstances (funds, job loss, etc.). Gekko was pretty free of any restraint. Of course, people went overboard and then recovered, but there's no whiff of any bump of that sort in Gekko's backstory.
• The author's intention: Oliver Stone is not exactly huge on subtlety and leaving things unspoken - particularly things that can be played for melodrama. If he thought Gekko was a drug user, we would've had an over-the-top scene in which fell down the stair with his nostrils caked in white powder.

Those guys rail out fat lines of yayo while banking millions and getting sucked off by young girls on their private g500s. Evidence lolgekko worked out alot I don't see him using any more than for rec

i'm going to say no. why? because the Gordon Gekko character was based on a composite of Ivan Boesky, Carl Icahn, and Asher Edelman. and there is no evidence that any of them consumed illicit drugs.