This article discusses the interaction between hormonal birth control and Lamictal and other birth control methods to consider.

Lamictal and Birth Control

Research has found that those using combined hormonal OCs (birth control pills that contain both synthetic estrogen and progestin hormones) experienced a greater than 60% reduction in the effectiveness of Lamictal. It was later discovered that this is due to the estrogen in combined hormonal contraceptives.

Estrogen in OCs can increase the speed of Lamictal’s metabolism in the body by inducing the liver enzymes involved. This may result in a lower concentration of Lamictal that won’t effectively treat the condition for which it was prescribed.

What’s more, during the hormone-free (placebo) pill week in combined hormonal OC packs, the concentration of Lamictal can double if the dose of it remains constant throughout the OC cycle.

Monitoring Use

Continuing to use estrogen-containing OCs or other combined-hormone contraceptives, including the contraceptive patch and ring, may require adjustments to Lamictal dosages.

Because the hormone-free placebo pills (or the patch- or ring-free week during use) can cause a potentially toxic increase of Lamictal in the body, monitoring levels of it while using hormonal contraceptives would be required.

However, it may not be practical to keep such a close watch on the concentration of Lamictal during the different points of the menstrual cycle.

An alternative would be to skip the hormone-free weeks, by not taking the hormone-free pills in a OC pill pack or using a new patch or ring immediately instead of waiting a week. That way, a healthcare provider can advise on the change in Lamictal concentration after the hormonal contraceptive is started. This may mean adjusting the Lamictal dose once, rather than throughout the menstrual cycle.

Other Methods of Birth Control

There are other birth control methods that may not impact the concentration of Lamictal in the body. These alternative options may allow for both medications to remain effective without requiring concentration monitoring or dosage adjustments.

These options may include:

Barrier methods: When used correctly and consistently, contraceptive methods such as condoms, diaphragms, and cervical caps can be effective methods of preventing unintended pregnancy for those using Lamictal. Because barrier methods contain no hormones, they will not impact the medication’s effectiveness. However, barrier methods are less effective in preventing pregnancy and have higher failure rates. Intrauterine device (IUD): Both the non-hormonal copper IUD and the IUDs containing levonorgestrel (a type of progestin) are unlikely to impact the metabolism of Lamictal. Contraceptive shot: Similar to the hormonal IUD, the injectable contraceptive containing medroxyprogesterone acetate (another type of progestin), Depo-Provera, may be yet another method to consider.

Remember that different methods of birth control have different levels of effectiveness, so be sure to discuss these options with a healthcare provider in advance.

Summary

Hormonal methods of birth control, including oral contraception (the pill), may interact with Lamictal (an anti-epileptic medication) and reduce its effectiveness. Therefore, people using Lamictal may want to consider other birth control methods to ensure that their birth control stays effective at preventing unwanted pregnancy.

A Word From Verywell

If you are taking Lamictal to treat your epilepsy or bipolar disorder, you may have concerns about how certain hormonal birth control methods, such as the combined oral contraceptive pill, will influence its effectiveness. Because hormonal contraceptives can interfere with Lamictal working effectively, you may want to consider alternative methods of birth control. Discuss the various options with your healthcare provider so you can ensure your Lamictal is working properly while still having safe sex.