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Does modafinil reduce the effectiveness of hormonal contraception?

The wakefulness drug modafinil, dubbed “Professor’s little helper” has in some circles become the go-to drug for pushing the clock back. Much of the distribution is conducted illicitly, meaning the patient information leaflet is often never seen by the person taking the pills. To many it’s therefore come as some surprise, that the patient information leaflet warns of an interaction between the drug and hormonal contraceptives.

The patient information leaflet provides no information on why this interaction may occur or the severity of the interaction, but it appears that Modafinil increases the effectiveness of the enzyme (CYP3A4/5) that metabolises contraceptive hormones. Notably, the same enzyme is inhibited by grapefruit juice. Though I’d certainly not suggest you try to use one to cancel out the other, but perhaps something along those lines could be an avenue for research. According to a review published in 2009 in the British Medical Journal the following drugs may limit the effectiveness of hormonal contraception:

“Barbiturates, Carbamazepine, Oxcarbazepine, Phenytoin, Primidone, Topiramate, Modafinil, Rifampicin, Griseofulvin, Certain antiretrovirals (such as ritonavir and nevirapine), Non-liver enzyme inducing antibiotics, Lamotrigine, Ciclosporin, Potassium sparing diuretics” 

Unfortunately there doesn’t seem to have been any actual direct research on impregnation rates but it undoubtedly seems wise to urge a great deal of caution and discuss the matter with your doctor if you use both modafinil and hormonal contraceptives. 

On the topic of hormonal contraceptives, the history is really quite fascinating. Check out Malcolm Gladwell’s (now pretty dated but still intriguing as ever) essay on how  politics affected the basic science of the pill’s creation.


Robertson P. (2002). Effect of modafinil on the pharmacokinetics of ethinyl estradiol and triazolam in healthy volunteers, Clinical Pharmacology & Therapeutics, 71 (1) 46-56. DOI:

Jean-Jacques, A. & Tripathi, V. (2009). Contraception for women: an evidence based overview, BMJ, 339 (aug07 1) b2895-b2895. DOI:

The information in this post should not under any circumstances be considered medical advice, do not adjust your medication without first consulting with your doctor. To keep up to date with this blog you can follow Neurobonkers on TwitterFacebookRSS or join the mailing list.


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