Antibiotics and birth control – the facts explained

contraceptive pill
Another million dollar question many females find themselves asking. If you are on birth control and find yourself prescribed antibiotics, you might wonder whether one might affect the other.

For years, women have been warned that their birth control could become less effective if they mix it with antibiotics.

The topic of antibiotics and contraception is one of great controversy. While there is sufficient evidence out there from individual studies, many argue that not enough clinical trials have been completed.

According to, some experts argue that studies that have been conducted are too small or poorly designed to determine the effects between individual antibiotics and birth control.

So, is there actually any cause for concern? The short answer is that most antibiotics do not interfere with nearly all methods of birth control, but there are a couple to be aware of.

Which antibiotics could affect my birth control?

Of course, this depends on what form of birth control you are on as some are not affected by antibiotics, but others are. According to the NHS, hormonal contraceptives that could be affected by other medicines include the combined pill, the mini pill, the patch, the vaginal ring and the implant.

Logically, the most common type of birth control to be affected by taking antibiotics would be the contraceptive pill. If the medication you are taking makes your vomit, then the pill you took that day may not have absorbed into your body and so might not count.

Luckily, research shows that hardly any antibiotics cancel out the role out contraceptives play on our bodies and especially because we may find ourselves prescribe antibiotics at least once a year. Research conducted by the Centers for Disease Control and Prevention shows that four out of five Americans could be getting antibiotics annually.

Of course, while there is some research out there on antibiotics and birth control, not every area has been covered.

Rifampin and my birth control

The only antibiotic that has proven to influence birth control is rifampin, also known as Rifadin or Rimactane. This can be used to treat or prevent diseases such as tuberculosis and meningitis.

Research shows that rifampin lowers the effectiveness by decreased the birth control hormone levels in females which are needed to prevent ovulation. It can also induce enzymes in your liver that can break down estrogen faster than normal, thus lowering hormone levels and the effectiveness of your birth control.

Research shows that these types of antibiotics can increase the enzymes in your body and can affect the quality of the pill, patch and the ring. Birth control methods that will not be affected by rifabutin or rifampicin are the progestogen only injection, the intrauterine device (IUD) or the intrauterine system (IUS).

The NHS suggests that you discuss your options with your doctor if you are taking these tablets for less than two months but want to continue using the same hormonal contraception.

Once the course of antibiotics is completed, there is still a chance your contraception may not be as effective, so it is advised you use other methods for 28 days – this is of course, if you do want to avoid pregnancy. Condoms, vaginal ring or the pull out method might be advised but discuss with your partner what you both feel is the right choice for you.

It is also possible that the antibiotic griseofulvin can interact with your birth control pill. You may be prescribed this medication to help treat several types of dermatophytosis – or ringworm. This can include fungal infections of the nails, scalp and skin if antifungal creams have not been successful.

If you are prescribed this tablet, then your doctor might suggest changing the dose of your birth control pill or change to a different form of birth control such as a condom.

Side effects of antibiotics and my birth control

While the two drugs should work just as well when taken together, it could be that mixed together, they cause some other side effects or increase the side effects that could already come along with the medications.

These side effects include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Changes in appetite
  • Headaches
  • Dizziness

Do remember though that vomiting could cause your birth control pill to not work, depending on the time taken and what pill it is, so make sure you monitor it correctly.

Of course, these side effects will vary depending on the person and the class of antibiotics and some people may not have any side effects at all.

Antibiotics not affected by birth control

While the only two medications that researchers have found to react to birth control. There are some we can be certain are not affected by hormonal birth control.

A study conducted in the Journal of the American Academy of Dermatology found that hormone levels remain unchanged when the following commonly prescribed antibiotics are taken with birth control pills:









and tetracycline. 

Most research conducted centers around antibiotics messing with your birth control, but what about the other way round? Unfortunately, there is not as much research conducted on this either.

It is also possible that hormonal contraceptives could change the effect of other medicines or affect what happens to your body.

Ciclosporin, which helps treat autoimmune and inflammatory conditions, can be affected by birth control. It is possible that the levels of ciclosporin may increase in your body which can cause harmful side effects. Research by pharmacytimes also states the two should not be mixed.

To summarise

To conclude, luckily, most antibiotics are safe when used with hormonal contraception but do keep in mind of the ones that are not. Remember, if you are prescribed any antibiotics and pregnancy is not on the cards for you, then do use other forms of contraception while you are taking the tablets and for the period advised after.

Please note that The Lowdown journalists are not medical professionals, so do seek advice from your doctor if you are prescribed antibiotics and are on birth control.

This guide was brought to you by The Lowdown. We are the world’s first contraception review platform, providing real-life experiences from thousands of reviews collected from our community of men and women.

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