Birth control, or contraception, is a device, medication, or procedure that helps prevent pregnancy. Types include barrier methods, hormonal birth control pills, intrauterine devices (IUDs), and sterilization. When used correctly, birth control can be up to 99.9% effective at preventing pregnancy.
Contraception can be highly effective, but certain factors can make it less reliable. One of these factors is interactions: when combining birth control with a drug or supplement affects how well the contraception works.
St. John's wort is an herbal supplement that people may use to help manage depression, anxiety, menopausal symptoms, and attention-deficit hyperactivity disorder (ADHD). It's widely known to have dangerous interactions with a variety of medications, including birth control pills.
Taking St. John's wort with birth control pills can weaken the effectiveness of the birth control pills. St. John's wort increases the activity of a liver enzyme (protein) called cytochrome P450 (CYP) 3A4. This makes your body break down the birth control pills too fast, which leads to lower levels of the pills in your system. It can lead to breakthrough bleeding and decreased contraceptive effectiveness.
2. Activated Charcoal
Activated charcoal is a fine, black powder. In medical settings, it's used to treat poisoning, overdoses, high cholesterol, hangovers, and upset stomach. It works by trapping chemicals in its pores. In recent years, it has been marketed as a wellness and "detox" supplement.
Taking activated charcoal and birth control pills together can decrease the amount of contraceptives your body absorbs, making birth control pills less effective at preventing pregnancy. To avoid this interaction, take activated charcoal at least three hours after or 12 hours before you take your birth control pills.
In most cases, antibiotics don't interact with birth control. The only exception is Rifadin (rifampin), an antibiotic used to treat tuberculosis. Rifadin can decrease the effectiveness of hormonal birth control, such as the pill, patch, ring, and implant.
Rifadin increases the activity of CYP enzymes that break down estrogens (female reproductive hormones) in your system. This can lead to lower levels of estrogen-containing birth control pills in your body, which makes them less effective. Always use a backup method of birth control while taking Rifadin and birth control.
Data is limited on whether other antibiotics interact with birth control. Take caution and use a backup method of contraception, such as condoms, while taking antibiotics.
4. Antifungal Drugs
Antifungal medications are used to treat fungal infections, such as athlete's foot and jock itch. They are available in topical, oral, and injectable forms.
Certain antifungals can interact with birth control. For example, Gris-PEG (griseofulvin) may decrease the effectiveness of hormonal contraceptives. Because of this, healthcare providers usually recommend using another form of contraception while taking Gris-PEG.
Some azole antifungals, such as Nizoral (ketoconazole) and Vfend (voriconazole), may also interact with hormonal birth control by blocking the enzyme responsible for breaking down hormonal contraceptives. This can lead to increased levels of the birth control in your system, which increases your risk of side effects, including nausea and breast tenderness.
Several anti-seizure medications interact with hormonal birth control by lowering the levels of the contraceptives in your system. This can make them less effective at preventing pregnancy. These anti-seizure drugs include:
- Tegretol (carbamazepine)
- Trileptal (oxcarbazepine)
- Depacon (valproate)
- Topamax (topiramate)
- Dilantin (phenytoin)
Combining hormonal birth control with the anti-seizure drug Lamictal (lamotrigine) can lead to lower levels of Lamictal in your system. This can make the drug less effective at managing seizures.
6. Human Immunodeficiency Virus (HIV) Medications
Certain HIV medications are known to interact with other drugs, including birth control. For example, the HIV drug Sustiva (efavirenz) can lower the effectiveness of hormonal contraception, including implants and the pill.
Many combination HIV medications contain efavirenz, such as Atripla (efavirenz/emtricitabine/tenofovir) and Symfi (efavirenz/lamivudine/tenofovir). Always check with your healthcare provider to see if your HIV regimen is safe to take with your birth control.
Birth control has been linked to certain nutritional deficiencies. One study found oral contraceptives can reduce vitamin B6, vitamin B12, folate, zinc, selenium, and magnesium levels.
Healthcare providers may recommend specific vitamins or dietary supplements, especially if you take birth control for a long period. However, there is no standard recommendation. It's important to talk to your healthcare provider about whether vitamin supplementation is necessary for you.
Other Considerations
Talk with your healthcare provider if you take birth control and need to start a new medication. Providing them with an up-to-date list of your medications and supplements can help them identify and prevent drug interactions. They can also discuss whether you'll need a backup form of birth control.
Contraception can be highly effective if used perfectly, but certain factors can make it less reliable. Certain medications and supplements can interact with birth control, reducing its effectiveness or worsening its side effects. These include St. John's wort, activated charcoal, antibiotics, antifungals, and drugs used to treat HIV and seizures.
Always consult a healthcare provider before starting new medications or supplements. They can help determine whether the drug or supplement will interfere with your birth control. If so, they may recommend a backup method of birth control.
