Drugs that could interfere with your oral contraceptive

Last Modified: 7/05/2022

birth control

This post was written by Caroline Rahrig, pharmacy intern, reviewed by Betsy Meisberger, PharmD, PGY1 Residency program coordinator, Parkview Health. 

Recent numbers show that 900,000 women aged 15-49 are currently taking some form of oral contraception. With this huge percentage of the population using these medications, it is important to consider how other medications affect your birth control.

How oral contraception works

Oral contraception works in multiple ways to help women prevent pregnancy, regulate their cycle, lessen painful menstruations, and aid with a variety of other conditions.

Drug interference

Taking other medications, either over-the-counter or prescription, can affect the way birth control works. Many times, these medications decrease the amount of oral contraception in the body, making it less effective in preventing pregnancy. While there are other forms of birth control, including IUDs, patches and vaginal rings, these forms may have other or additional medication interactions and should also be discussed with your pharmacist or provider.

There are many things to consider when taking birth control, including what other medications you are taking and if those medications decrease the effectiveness of the birth control. Examples of such medications include:

Certain types of antibiotics

  • Examples: Nafcillin, Rifampin and Rifabutin
  • Prescribed to treat: severe infections
  • Over the counter or prescription: prescription

St. John’s wort

  • Used to treat: an herbal remedy that may help with depression or anxiety
  • Over the counter or prescription: over the counter

Antiseizure medications

  • Examples: Phenytoin, Topiramate, Carbamazepine
  • Prescribed to treat: to treat and prevent seizures
  • Over the counter or prescription: prescription


  • Example: Griseofulvin
  • Prescribed to treat: severe fungal infections in the body
  • Over the counter or prescription: prescription   


  • Example: Ritonavir, Darunavir
  • Prescribed to treat: HIV
  • Over the counter or prescription: prescription               
Addressing potential efficacy concerns

It’s important that you don’t stop taking your prescription medications. Instead, use a back-up method, such as a condom, during the entire time of taking the medications listed above as well as for 7 days after completing your medications.

Back-up plan

In the case that you have unprotected sex and are taking the medications listed above, there are several options including emergency contraception. Emergency contraception can be bought over the counter at your local retail pharmacy and is only effective for 72 hours after unprotected sex. After this 72-hour time period, consult your provider for additional options.

Other substances worth mentioning


When taking birth control, NSAIDS such as Aleve®, Advil, or aspirin may increase the amount of hormonal contraception in your body. This can cause negative effects, including increasing the risk of clots. While this is rare, it may occur if someone is susceptible to clots and takes daily NSAIDS.


Tobacco in products like cigarettes, cigars, chew, and e-cigarettes used with birth control can cause serious heart issues. People who use tobacco on a regular basis should not be using birth control products that contain estrogen.


Melatonin is a helpful over-the-counter sleep agent that many people take right before bed. If taking melatonin on birth control, this will increase the effect of melatonin. Women on oral contraception should be careful when taking melatonin for sleep as it may cause extreme drowsiness.

It is always important to be mindful of the medications that you are taking. If you are ever concerned about any interactions with your birth control, ask your pharmacist or provider to learn more!




Kimberly Daniels et al. Current Contraceptive Status Among Women Aged 15–49: United States, 2017–2019. Center for Disease and Control. Published October 2020. Accessed June 10, 2022.

Melatonin. Mayo Clinic. Published May 3, 2021. Accessed June 10, 2022.

Rebecca H Allen. Combined estrogen-progestin oral contraceptives: Pateint selection, counseling and use. UpToDate. Published June 7, 2022. Accessed June 10, 2022.



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