Synthetic steroid (STEAR)
Tibolone 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 Tibolone (Tibolone). The combination is generally fine at 2.5mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Tibolone 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 Tibolone acts on CYP3A4 determines whether Tibolone affects contraception. Most agents in Synthetic steroid (STEAR) have no clinically meaningful effect on the pill at 2.5mg.
Practical guidance
According to the prescribing information for Tibolone, women on hormonal contraception should review Tibolone 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 Tibolone therapy is the standard mitigation.
Frequently asked questions
Will Tibolone make my pill less effective? ▾
Most Synthetic steroid (STEAR) medications at 2.5mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Tibolone states whether the interaction is meaningful.
Do I need a backup contraceptive on Tibolone? ▾
Backup contraception is needed only when there is a documented interaction between Tibolone and the contraceptive method. For most users at 2.5mg, no backup is required. The pharmacist confirms whether Tibolone interacts with hormonal contraception.
Products containing Tibolone
More on Tibolone
- With alcoholTibolone and alcohol — is it safe to drink?
- With foodShould Tibolone be taken with food?
- Side effectsTibolone side effects: common, rare and warning signs
- Dosage guideTibolone dosage guide: how much to take and when
- OnsetHow fast does Tibolone start working?
- DurationHow long does Tibolone last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.