Does alcohol reduce the effectiveness of the pill?
Alcohol does not affect the functioning of the birth control pill.
According to Planned Parenthood, the following forms of contraception will continue to work in the same way if a person drinks alcohol:
- birth control pills
- intrauterine devices (IUDs)
- vaginal rings
- the Depo-Provera shot
With correct use, these methods are 91–99 percent effective. The birth control pill would be 99 percent effective if everyone used it correctly all the time. As they do not, it is about 91 percent effective in reality.
If a person drinks so much alcohol that they vomit within 2 hours of taking their pill, it will be less effective. If this happens, they should take another pill as soon as possible and see a doctor for further advice.
Alcohol can also affect a person’s judgment and memory. A person consuming an excessive amount of alcohol may forget to take the pill that day.
Or, if they use the progestin-only pill (POP), they may forget to take it within the proper timeframe. The POP is only effective if an individual takes it within the same 3-hour period every day.
Missing a dose can cause ovulation, which is when an ovary releases an egg.
The 3 days on which a female is most fertile are the 2 days leading up to ovulation and the day it occurs. If they have sexual intercourse with a male during the most fertile days and do not use contraception, they have a 27–33 percent chance of becoming pregnant.
If a person misses a birth control pill and wishes to avoid unintended pregnancy, they should use condoms or another form of contraception in addition to the pill for 4 weeks.
Does birth control affect alcohol tolerance?
People who take birth control pills metabolize, or process, alcohol more slowly than those not on the pill. This is because the liver has to metabolize both the alcohol and the hormones in the medication.
As a result, alcohol stays in the body for an extended period, and its effects last longer. People also remain intoxicated for longer during their menstrual periods, when the body releases more hormones.
Females typically tend to get intoxicated more quickly than males. This is because their bodies contain less of the enzyme that breaks down alcohol, which is called alcohol dehydrogenase.
Drinking excessive amounts of alcohol carries other risks, especially concerning sexual behavior.
Risky sexual behavior
People who are intoxicated may not use condoms or other contraception to protect themselves against sexually transmitted infections (STIs) or unintended pregnancy. Others may regret their choice of sexual partner.
The authors of a study from 2015 examined the relationship between alcohol and sexual behavior in adults aged 26, 32, and 38. They found that 13.5 percent of men and 11.9 percent of women aged 38 experienced unwanted outcomes following their behavior while intoxicated.
These outcomes included regretting sex, regretting the choice of sexual partner, and not using contraception.
There is a link between alcohol and sexual assault. A publication released by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) states that approximately 50 percent of people who report sexual assault say that they were drinking at the time of the assault.
The same report states that men who have been drinking alcohol are responsible for 50 percent of sexual assaults.
It is important to note that even if a person has been drinking before someone sexually assaults them, they are in no way to blame. The fault always lies with the perpetrator.
People who are taking the birth control pill and know that they will be drinking should plan accordingly. They could consider:
- Setting an alarm to remind them to take their pill on time
- Taking their pill in the middle of each day, when they are less likely to be drinking
- Carrying a barrier form of birth control, such as condoms, to prevent STIs
- Explaining to their partner that they wish to use condoms as a backup method of contraception while drinking