NSAID (phenylacetic acid)
Diclofenac 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 Diclofenac (Diclofenac). The combination is generally fine at 25mg, 50mg, 75mg, 100mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Diclofenac 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 Diclofenac acts on CYP3A4 determines whether Diclofenac affects contraception. Most agents in NSAID (phenylacetic acid) have no clinically meaningful effect on the pill at 25mg, 50mg, 75mg, 100mg.
Practical guidance
According to the prescribing information for Diclofenac, women on hormonal contraception should review Diclofenac 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 Diclofenac therapy is the standard mitigation.
Frequently asked questions
Will Diclofenac make my pill less effective? ▾
Most NSAID (phenylacetic acid) medications at 25mg, 50mg, 75mg, 100mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Diclofenac states whether the interaction is meaningful.
Do I need a backup contraceptive on Diclofenac? ▾
Backup contraception is needed only when there is a documented interaction between Diclofenac and the contraceptive method. For most users at 25mg, 50mg, 75mg, 100mg, no backup is required. The pharmacist confirms whether Diclofenac interacts with hormonal contraception.
Products containing Diclofenac
More on Diclofenac
- With alcoholDiclofenac and alcohol — is it safe to drink?
- With foodShould Diclofenac be taken with food?
- Side effectsDiclofenac side effects: common, rare and warning signs
- Dosage guideDiclofenac dosage guide: how much to take and when
- OnsetHow fast does Diclofenac start working?
- DurationHow long does Diclofenac last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.