This one requires few words, and is a key belief of those whom have chosen to call themselves Libertarians.
Nothing you do to yourself should be illegal. For a crime to have been committed, there must be a victim. If you willingly ingest a product of your own free will, there is no crime. Willingly engage in a behavior that only endangers yourself, there is no crime. Willingly consent with another adult, there is no crime.
If there is no victim, there is no crime.
You simply cannot regulate someone’s behavior. People will do what they want. Let’s stop making victimless crimes, and let people pursue their own version of happiness.