Dual 5α-reductase inhibitor (type 1 and type 2)
Dutasteride 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 Dutasteride (Dutasteride). The combination is generally fine at 0.5mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Dutasteride 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 Dutasteride acts on CYP3A4 determines whether Dutasteride affects contraception. Most agents in Dual 5α-reductase inhibitor (type 1 and type 2) have no clinically meaningful effect on the pill at 0.5mg.
Practical guidance
According to the prescribing information for Dutasteride, women on hormonal contraception should review Dutasteride 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 Dutasteride therapy is the standard mitigation.
Frequently asked questions
Will Dutasteride make my pill less effective? ▾
Most Dual 5α-reductase inhibitor (type 1 and type 2) medications at 0.5mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Dutasteride states whether the interaction is meaningful.
Do I need a backup contraceptive on Dutasteride? ▾
Backup contraception is needed only when there is a documented interaction between Dutasteride and the contraceptive method. For most users at 0.5mg, no backup is required. The pharmacist confirms whether Dutasteride interacts with hormonal contraception.
Products containing Dutasteride
More on Dutasteride
- With alcoholDutasteride and alcohol — is it safe to drink?
- With foodShould Dutasteride be taken with food?
- Side effectsDutasteride side effects: common, rare and warning signs
- Dosage guideDutasteride dosage guide: how much to take and when
- OnsetHow fast does Dutasteride start working?
- DurationHow long does Dutasteride last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.