I have two concerns:

My boyfriend claims psychedelics open your mind to new ideas/perspectives and help you experience the "spiritual world." I maintain that anything you see or think is just a result from a brain overloaded on chemicals. However, I am beginning to feel closed-minded, and I would like to have your opinion on psychedelics — are they beneficial if used for a one-time experience, and will they immediately/permanently alter the way I view the world and myself? Given that I have doubts, should I even try anything this mind-altering? I have read your answers pertaining to short-/long-term effects, but I wanted to know if there was any actual evidence of the beneficial effects.

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 know that it is extremely dangerous to mix viagra (or other ED drugs) and poppers (amyl nitrate), and that one should wait for 24 hours after using viagra (to let it get out of your system) before using poppers. My question is what is the waiting period after using poppers before it is safe to use viagra? In other words, how long before the physiological effects of poppers wear off?