What is hormonal contraception?
Hormonal contraception methods include:
- Oral contraceptive pills (the Pill)
- The patch (Evra®)
- Injectable contraception (Depo-Provera®)
- Intrauterine device (IUD) (Mirena®, Kyleena™). IUDs are also known as intrauterine contraception (IUC)
- Vaginal ring (NuvaRing™)
- Implant (Nexplanon®) – a small rod inserted under the skin of the arm
Hormonal contraception uses 1 or 2 hormones similar to estrogen and progestin, which your body produces. It can have many clinical uses including:
- Preventing pregnancy (all methods)
- Gender-affirming/transition care (the Pill)
- Acne control (some methods)
- Preventing heavy bleeding during menstruation (IUDs)
- Other uses
Talk to your health care provider about which method is right for you.
Does hormonal contraception affect my other medications?
Hormonal contraception can make some medications (or herbal supplements) work less effectively, such as anti-seizure drugs.
Ask your health care provider about how your hormonal contraception may affect your other medications. There may be contraception methods that work better with the medications you are taking. Your provider may also suggest you change your medication or the dose.
Can other medications affect my contraception?
Yes. Certain medications may affect how well your hormonal contraception works. Some may stop them from working entirely.
These include, but are not limited to:
- Antibiotics such as rifampin
- Anticonvulsants or anti-seizure medications such as carbamazepine (Tegretol®), phenytoin (Dilantin®), oxcarbazepine (Trileptal®), primidone or topiramate (Topamax®)
- Antifungal medications such as griseofulvin
- Antiretroviral such as ritonavir
- Herbal medications such as St. John’s wort
It is important that you talk to your health care provider and pharmacist about any medications, dietary supplements, or recreational drugs that you are taking. They can discuss medication options with you that will not affect your contraception.
How does hormonal contraception prevent pregnancy?
Pregnancy occurs when an egg is fertilized by sperm. The fertilized egg attaches to the lining of the uterus, where it grows and develops into a fetus.
Hormones control the release of the egg and prepare the body to support the growth of a fetus.
Hormonal contraception helps prevent pregnancy by doing one or more of the following:
- Preventing ovulation (i.e., the ovary does not release an egg)
- Thickening the cervical mucus, which makes it difficult for the sperm to enter the uterus
- Thinning the lining of the uterus, in case a person does ovulate (e.g., if they miss taking pills), making it difficult for an egg to attach
How can I make sure I don’t get pregnant if I’m taking medications which affect my hormonal contraception?
Talk to your health care provider about your options. You may need to use a barrier method as well as your hormonal contraception. These include:
- Cervical caps
These methods are not affected by medications. Condoms are the only contraceptive method that protects you against sexually transmitted infections (STIs).
Some anti-seizure medications and other drugs, such as isotretinoin (Accutane®) for acne, significantly increase the risk of birth defects. It is important to use effective contraception to prevent pregnancy and to plan any pregnancy carefully with your health care provider’s advice if you use these medications.
Speak to your health care provider about how long you should use a barrier method, even after you stop taking a medication that affects your hormonal contraception.
For More Information
For more information on contraception options and how to prevent pregnancy while taking medications or herbal supplements, speak with your health care provider, pharmacist, or public health nurse.
For information about sexually transmitted infections, see HealthLinkBC File #08o Preventing Sexually Transmitted Infections (STIs).