At the end of the day, it's YOUR body. Realistically, as a consenting adult, whatever you put in is fundamentally your own business.
Similarly, as long as all parties are consenting and competent adults, what sexual acts you engage in and why you do so are simply none of the governments business. Consent, competence, and (at a minimum) the local definition of adulthood are the critical variables that may be legitimately questioned.
Nothing in this relieves you of any responsibility for the results of your acts - if, while chemically altered, you engage in criminal acts - you are no less responsible than if stone cold sober. Similarly, if while engaging in physical friskies with a pleasant partner(s) you manage to damage yourself or playmate(s), you bear criminal and civil liability for your bad acts resulting in physical injury.
To the extent we fail to realize this fundamental truth in favor of bigotry, distaste, or "because gawd said so", we fail both ourselves and our nation. We fail the cause of freedom, upon which this nation was founded.
Prohibition has demonstrably failed spectacularly - both in version 1.0 (Alcohol) and 2.0 (the Drug War nee' "The War on Civil Rights") on two occasions in our country - perhaps, like the man hitting himself in the head with a baseball bat, we should stop and enjoy how good the cessation of pain truly is.
I am all for treatment, punishment of bad conduct (assault, rape, homicide, arson, etc ad nauseum) - but spending huge sums to prop up a violent black market with obscene profit margins, where the true addicts end up feeding their self-destructive hungers regardless...perhaps not so much. If we must have addicts, what say we do it without the far more destructive black market?
Similarly, on sexual matters, there exist practices and reasons for sexual interaction that many find repugnant or just icky. That's not a legitimate reason for a law. Neither is "Gawd said so" or "it's immoral". It is neither our business nor societies why two or more competent and consenting adults voluntarily get together for genital frolics; similarly what acts they perform so long as medical mishap to which one or more involved parties objects do not occur - it's simply none of our business, short of corpses turning up.
Self-ownership - wacky idea that it is, may just cut way down on the misery in the world.