Selective serotonin reuptake inhibitor (SSRI)
Fluoxetine 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 Fluoxetine (Fluoxetine). The combination is generally fine at 10mg, 20mg, 40mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Fluoxetine 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 Fluoxetine acts on CYP3A4 determines whether Fluoxetine affects contraception. Most agents in Selective serotonin reuptake inhibitor (SSRI) have no clinically meaningful effect on the pill at 10mg, 20mg, 40mg.
Practical guidance
According to the prescribing information for Fluoxetine, women on hormonal contraception should review Fluoxetine 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 Fluoxetine therapy is the standard mitigation.
Frequently asked questions
Will Fluoxetine make my pill less effective? ▾
Most Selective serotonin reuptake inhibitor (SSRI) medications at 10mg, 20mg, 40mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Fluoxetine states whether the interaction is meaningful.
Do I need a backup contraceptive on Fluoxetine? ▾
Backup contraception is needed only when there is a documented interaction between Fluoxetine and the contraceptive method. For most users at 10mg, 20mg, 40mg, no backup is required. The pharmacist confirms whether Fluoxetine interacts with hormonal contraception.
Products containing Fluoxetine
More on Fluoxetine
- With alcoholFluoxetine and alcohol — is it safe to drink?
- With foodShould Fluoxetine be taken with food?
- Side effectsFluoxetine side effects: common, rare and warning signs
- Dosage guideFluoxetine dosage guide: how much to take and when
- OnsetHow fast does Fluoxetine start working?
- DurationHow long does Fluoxetine last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.