Does Alcohol Affect The Effectiveness Of the Birth Control Pill?

Duly Care
Jul 14
7 min read

The birth control pill is one of the most common ways for women to prevent an unintended pregnancy. It is taken every day and works by using hormones. Because it needs to be taken regularly and is processed by the body, many women wonder if certain habits - like drinking alcohol - might change how well the pill works. This question often comes up during social events, holidays, or weekends, when both drinking and sexual activity are more likely.

In this blog, we will explain what the birth control pill is and how it works, and then answer a common question that many women have: does alcohol affect the effectiveness of the birth control pill?

Key Takeaways:

The birth control pill, also known as the oral contraceptive pill, is a hormonal medication taken daily to prevent an unintended pregnancy. These pills contain synthetic versions of the natural female hormones estrogen and progesterone.
After drinking, alcohol enters the bloodstream and is broken down slowly by the liver. It can affect brain function, making it harder to think clearly or remember daily tasks like taking medications.
Alcohol does not stop the pill from working. But if drinking leads to vomiting soon after taking the pill or causes you to miss pills, the effectiveness may be reduced.
Drinking responsibly, staying mindful of pill intake, and taking prompt action in case of vomiting can ensure reliable effectiveness against pregnancy.

What is the Birth Control Pill?

The birth control pill, also known as the oral contraceptive pill, is a hormonal medication taken daily to prevent an unintended pregnancy. These pills contain synthetic versions of the natural female hormones estrogen and progesterone. These hormones prevent pregnancy mainly by stopping ovulation, which means no egg is released for sperm to fertilise. The pill also thickens the mucus at the entrance of the uterus, making it harder for sperm to travel, and thins the inner lining of the uterus so that a fertilised egg is less likely to attach to the lining and develop into a pregnancy.

When taken correctly, the birth control pill is highly effective. With perfect use—meaning a pill is taken at the same time every day without missing any doses- the pill can be up to 99 percent effective. However, in typical daily life, missed or late pills are common. Because of this, the pill is about 91 percent effective in real-world use.

The pill does not become effective immediately in all cases. If the pill is started within the first five days of a period, it begins working right away. But if started at any other time in the cycle, it usually takes seven full days of daily use before it becomes reliable for pregnancy prevention. During that time, it is important to use a backup method like condoms.

For the pill to stay effective, it must be taken once a day at around the same time. This helps maintain steady hormone levels in the body. Missing a pill or taking it late can cause hormone levels to drop, which increases the chance of ovulation and reduces protection.

There are two main types of birth control pills: the combined oral contraceptive pill, which contains both estrogen and progestin, and the progestin-only pill (also called the mini pill). The timing is even more important for progestin-only pills, which need to be taken at the exact same time every day. A delay of even three hours may lower effectiveness.

What Happens in the Body When Alcohol Is Consumed?

After alcohol is consumed, it travels quickly through the digestive system and enters the bloodstream. From there, it spreads throughout the body and begins to affect different organs, especially the brain and the liver.

The liver plays a major role in breaking down alcohol. It uses natural chemicals called enzymes to change alcohol into other substances that can be safely removed from the body. One of these enzymes, called alcohol dehydrogenase, breaks alcohol down into a compound that is then processed further and passed out through urine or breath. This process happens at a steady rate—about one standard drink per hour. Drinking more than that causes alcohol to build up in the body.

This breakdown process is important because the liver also handles other substances, including hormones. Just like alcohol, the hormones in the birth control pill are processed in the liver. That is why it is helpful to understand how alcohol moves through the body when discussing any medicine that contains hormones.

As alcohol levels rise, it starts to affect how the brain works. It can lead to dizziness, poor coordination, slower thinking, and difficulty focusing. Even at lower levels, alcohol may affect memory or decision-making, which can disrupt regular routines.

In some cases, alcohol can also irritate the stomach. This might cause nausea (a sick feeling in the stomach) or vomiting (throwing up). These effects can interfere with the way medicines are absorbed, especially if they are taken by mouth and need time to settle in the stomach.

How Alcohol May Affect the Effectiveness of the Birth Control Pill

Here are some ways in which alcohol may affect the effectiveness of the birth control pill:

No direct interaction: Research reveals no direct chemical interaction between alcohol and the hormones in the birth control pill. Alcohol does not reduce the pill’s ability to suppress ovulation, thicken the cervical mucus, and thin the inner lining of the uterus. Thus, the pill’s hormonal mechanism remains fully effective even when alcohol is consumed in normal amounts.
Concerns in case of vomiting: A key risk arises if vomiting occurs shortly after taking the pill, typically within two hours. Vomiting can prevent full absorption of the hormonal dose, potentially reducing the effectiveness of the pill. In such a scenario, a replacement pill should be taken as soon as possible, and the instructions provided in the pill pack should be referred to for any additional steps. This approach makes up for any missed or unabsorbed dose.
Effect on pill intake and routine: The most significant effect of alcohol may come from not remembering to take the pill or daily pill routine. Even moderate drinking can impair concentration and awareness. This increases the risk of missing the daily pill or taking it late. Missing a single dose or delaying intake by more than 24 hours can weaken its contraceptive effectiveness.
Liver enzyme effects and hormone duration: Some studies have explored whether alcohol influences the liver enzymes that metabolise hormonal contraceptives. While slight changes in enzyme activity have been observed, current medical reviews indicate these are minimal in typical drinking patterns and unlikely to reduce hormone levels enough to affect contraceptive performance. On the contrary, hormonal changes caused by the pill may slightly prolong the presence of alcohol in the body, potentially extending feelings of intoxication.
Potential risk of clots when combined with heavy drinking: Both the combined oral contraceptive pill and heavy alcohol consumption are independently associated with a small increase in the risk of blood clots forming in veins. When heavy drinking is combined with a hormonal contraceptive like the COCP, the risk becomes slightly greater. Light to moderate alcohol intake does not significantly elevate risk of clot for most healthy women. However, those over the age of 35, who smoke, or who have existing clotting disorders, should consult a doctor before mixing alcohol and the pill.

In summary, alcohol does not directly affect the way the birth control pill works. The pill remains highly effective as long as it is taken correctly and absorbed properly. The main concern lies in how alcohol may indirectly interfere with consistent use or absorption, rather than with the pill’s action itself.

Conclusion

The birth control pill remains highly effective even if alcohol is consumed. There is no direct interference with its action. The main concerns revolve around vomiting soon after taking the pill and the possible disruption of pill routine, leading to missed doses. Drinking responsibly, staying mindful of pill intake, and taking prompt action in case of vomiting can ensure reliable effectiveness against pregnancy.

Frequently Asked Questions (FAQs)

Can moderate alcohol consumption make the pill ineffective?
The level of alcohol in the body does not affect the pill’s effectiveness directly. Pregnancy risk arises mainly from forgetting to take the pill or vomiting.
What should occur if vomiting happens after taking the pill?
If you vomit (throw up) within two hours of taking the birth control pill, your body might not have had enough time to fully absorb the hormones contained in the pill. This means the pill may not be fully effective. If you vomit shortly after taking the pill, take another one as soon as you can and refer to the pill pack for any additional steps.
Does the pill make alcohol stay in the body longer?
Some evidence suggests the pill may extend alcohol presence in the body, leading to a prolonged feeling of intoxication. However, the evidence is not very conclusive.
Does drinking heavily while using the pill raise health risks?
Heavy drinking while using the birth control pill can slightly raise the risk of blood clots, particularly in women with other risk factors.

Important

This blog, including its text, images, and infographics, is for educational purposes only and not a substitute for professional medical advice. For personalised advice, always consult a doctor.