Estrace 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 Estrace (Estradiol). The combination is generally fine at 0.5mg, 1mg, 2mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Estrace 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 Estradiol acts on CYP3A4 determines whether Estrace affects contraception. Most agents in Hormones and Birth Control have no clinically meaningful effect on the pill at 0.5mg, 1mg, 2mg.
Practical guidance
According to the prescribing information for Estradiol, women on hormonal contraception should review Estrace 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 Estrace therapy is the standard mitigation.
Frequently asked questions
Will Estrace make my pill less effective? ▾
Most Hormones and Birth Control medications at 0.5mg, 1mg, 2mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Estradiol states whether the interaction is meaningful.
Do I need a backup contraceptive on Estrace? ▾
Backup contraception is needed only when there is a documented interaction between Estrace and the contraceptive method. For most users at 0.5mg, 1mg, 2mg, no backup is required. The pharmacist confirms whether Estradiol interacts with hormonal contraception.
More on Estrace
- With alcoholEstrace and alcohol — is it safe to drink?
- With foodShould Estrace be taken with food?
- Side effectsEstrace side effects: common, rare and warning signs
- Dosage guideEstrace dosage guide: how much to take and when
- OnsetHow fast does Estrace start working?
- DurationHow long does Estrace last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.