With full knowledge of what could happen (because effects are often not uniform), and with the right care and support I would think it can be done ethically.
Look at the trials of using LSD/mushrooms/MDMA to help people work through serious trauma. Done well it looks to be positively life changing, done poorly and it seems to be horrifying.
Fine, so print warnings on the bottle and make me sign a disclaimer. Isn’t it more harmful to create a black market with no quality controls? Isn’t it more harmful to ruin countless lives with felony convictions?
Not analogous at all. At this point, I would say what are the ethics on preventing someone from doing what they want to themselves if it does not hurt someone else.