Or just “I don’t do drugs”, or “I don’t do recreational drugs”?
Or “I don’t smoke weed” and “I don’t drink alcohol” when they come up, separately?
I wouldn’t generally say it at all unless I’m in a situation where I’m offered recreational drugs such as cannabis or alcohol.
My understanding is the term ‘straight edge’ might be more well known than ‘teetotal’, but neither are completely known by everyone.
I take straight edge to mean not doing any recreational drugs. However I read that straight edge can have punk culture connotations that some people might maintain are part of it. Like I might meet a punk straight edger who claims I’m not really straight edge unless I have connections to the punk scene. They also apparently often claim you need to be vegan to be straight edge, I am vegan though coincidentally but not for reasons relating to straight edge culture.
Teetotal I believe most often means abstinence from simply alcohol, but can be used to mean abstaining from all recreational drugs (I think). It may be more well known as just not drinking alcohol. For example teetotallers often still smoke weed.
Apologies if I misrepresented any of these terms.
I live in Wisconsin, and if there’s one thing Wisconsin is known for is a strong drinking culture. I’ve had extremely good luck with simply saying “not tonight” or “no thank you” or at strongest “I have to be good for my drive home”
If you specifically identify yourself as a teetotaler or straight edge or whatever could be interpreted as seeing yourself as better than others who just want to experience an altered state of mind, which is not a good first impression to make.