Other than, on one theory of the origin of homosexuality, a hormonal flush during fetal development, I’m fairly sure the answer is “no.” (But medical or pharmaceutical experts should validate that.)
One common effect of certain drugs, in both the recreational-drug and pharmaceutical-drug meanings, is to reduce inhibitions – which means that any Kinsey-1 and -2 people who have been in self-denial about slight to moderate same-sex attraction may find themselves more open to it. I’ve heard people report this effect with marijuana and most particularly with Ecstasy.
Well, at some point, there was a proposal to the US military for looking into research on a so-called ‘gay bomb’, which in theory would incapacitate an enemy platoon by… well, having them give each other a good rogering, so to speak.
However, the proposal admits that no suitable chemical was then known, and to my knowledge, there isn’t one now, either.