What is, overall, safer for your body: alcohol or marijuana?

Does acid (LSD) have a detrimental affect on women who use the birth control pill? Is it possible for a woman to be impregnated by pre-ejaculatory fluids four days after the menstrual cycle after unprotected sex?

I recently drank one shot of absinth(e) mixed with water at a party. I read up on it online and opinions differ vastly as to the potential for negative side effects. At this point my imagination has me suffering every possible one.

I would like to know the true possible effects and if one drink could realistically cause them. If it helps, the brand I had contained 100mg of thujone and it was Czech and I'm told they use an extract which is worse than using straight wormwood.

I hope you can help because I'm a little freaked out, the guy who gave it to me drank it extensively and recently committed suicide and I'm convinced the cause in part was the Absinthe.

I have a history of "experimentation" (infrequent or occasional use of ecstasy, 'shrooms, and other drugs — mostly prescription pills). I am completely sober now, but am worried about long-term damage to my brain. I used drugs infrequently (no more than three to five times for each substance), but drank regularly. How worried should I be? Is there anything I can do to combat long-term effects?

Recently, I have heard about a new hallucinogen available called salvia dinorium. Some of my friends have tried it and they tell me it is an incredible experience and that when you hallucinate, you have the perception of being brought back in time. Before I even think about trying this, however, I would like to have a more precise idea of what the effects are and what the possible risks of taking salvia are.