Lamictal with the birth control pill
Many women of reproductive age take a combined or progestogen-only oral contraceptive while also using a chronic medication such as Lamictal (Lamotrigine). The combination is generally fine at 25mg, 50mg, 100mg, 200mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Lamictal can affect contraceptive efficacy
Combined and progestogen-only contraceptives are metabolised through CYP3A4. Strong CYP3A4 inducers (some antiepileptics, rifampicin, St John's Wort) lower contraceptive plasma levels and reduce efficacy. Whether Lamotrigine acts on CYP3A4 determines whether Lamictal affects contraception. Most agents in Neurological Medications have no clinically meaningful effect on the pill at 25mg, 50mg, 100mg, 200mg.
Practical guidance
According to the prescribing information for Lamotrigine, women on hormonal contraception should review Lamictal with the prescribing pharmacist or doctor. Where an interaction is documented, additional barrier contraception or switching to a non-oral method (IUD, implant) for the duration of Lamictal therapy is the standard mitigation.
Frequently asked questions
Will Lamictal make my pill less effective? ▾
Most Neurological Medications medications at 25mg, 50mg, 100mg, 200mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Lamotrigine states whether the interaction is meaningful.
Do I need a backup contraceptive on Lamictal? ▾
Backup contraception is needed only when there is a documented interaction between Lamictal and the contraceptive method. For most users at 25mg, 50mg, 100mg, 200mg, no backup is required. The pharmacist confirms whether Lamotrigine interacts with hormonal contraception.
More on Lamictal
- With alcoholLamictal and alcohol — is it safe to drink?
- With foodShould Lamictal be taken with food?
- Side effectsLamictal side effects: common, rare and warning signs
- Dosage guideLamictal dosage guide: how much to take and when
- OnsetHow fast does Lamictal start working?
- DurationHow long does Lamictal last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.