Is there any prohibition in The Great Gatsby?

The Prohibition created another opportunity for Wolfshiem to begin a brand new shady endeavor, which he ultimately hooked Gatsby into. Because alcohol was outlawed, it was harder to come by(obviously); however, in the 1920's you could get alcohol as a prescription drug and drug stores were allowed to carry it. So Gatsby and Wolfshiem opened up numerous drug stores together and made a profit by selling alcohol under the table. This is where all of Gatsby's wealth comes from (or so it's inferred), which enables him to throw the parties, which increases his "popularity", et cetera, et cetera...