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?
No research was found that showed any direct information or research about LSD and birth control pills, probably because LSD has been illegal in the U.S. since 1966. A few things to think about however... LSD is a member of an ergot alkaloid chain named d-lysergic acid diethylamide. Ergot has both medicinal purposes and poisonous effects. The most important drugs produced from ergot are ergotamine, used to treat migraines, and ergonovine, used to control blood loss from the uterus following childbirth or an abortion. It's reasonable to believe that ergonovine is the form of ergot that might relate to the birth control pills. Ergonovine works by causing the muscles of the uterus to contract, which compresses the blood vessels and thus reduces bleeding.
Other things to think about are the liver and your blood pressure. Once in the body, LSD is quickly absorbed and cleared out of the bloodstream. After two hours, less than 10 percent of the drug is still active; most is already broken down by the liver into active by-products. The progestins and estrogens in birth control pills affect the general functioning of the liver. Some practitioners suggest that women only take the pills when liver function test results are fully normal. What does this mean for a tripping woman on birth control pills? A Ph.D. dissertation, or some new medical research perhaps, but common sense tells us that the hormones might very well interfere in some way with LSD absorption by your body. Does this simply mean that more LSD will be available to your brain and you'll have a more intense trip, or that the LSD absorption may be chemically altered by the effects of hormones on your liver function? Your guess is as good as anyone's.
Secondly, one of the side effects of LSD is increased blood pressure, as is one of the side effects of birth control pills. There are usually no direct symptoms of high blood pressure, yet when taking both drugs, your heart could be working harder than normal and your arteries put under great strain. Both the pill and LSD can also have side effects of headaches and nausea.
Lastly, LSD and other hallucinogenics disrupt the action of the neurotransmitter serotonin in your brain. It is a chemical involved in the transmission of nerve impulses between nerve cells. It is thought to be instrumental in controlling states of consciousness and mood. How or if birth control hormones affect the neurotransmitter serotonin is not known.
You wouldn't want to become or be pregnant while on LSD as it can cause spontaneous abortions, and the verdict is still not in regarding possible birth defects in a child born to an LSD user. If you are taking LSD regularly, you may want to switch to a form of birth control other than the pill. Otherwise, it seems prudent to use a back up method of contraception if you are having sex while tripping.
As far as your second question, it is rather unlikely, although certainly possible, for a woman to get pregnant four days after her menstrual period. Most women ovulate about half-way into their cycle (if it's 28 days), or more accurately, 14 days before their next period. If one has irregular cycles, or is under extra stress, has changed her diet or exercise patterns, or has had any lifestyle changes during the last few weeks, it is possible that her cycle would not be exactly 28 days. This is true even if you've had a consistent cycle for a long time. For more about menstrual cycles, see questions Woman's menstrual cycle, Fertile times?, and Optimal times to conceive? in the Go Ask Alice! Sexual and Reproductive Health archives.Alice!