What to Know About Birth Control Interactions with Dietary Supplements and Herbal Remedies

According to the Centers for Disease Control and Prevention (CDC), between 2017-2019, 65% of women between the ages of 15 and 49 in the U.S. reported using a form of contraception — more commonly known as birth control. According to the CDC’s most recent National Health and Nutrition Examination Survey, between 2017-2019, over 63% of U.S. women reported taking a dietary supplement in the last 30 days.

These statistics on their own may not surprise you. However, you may be unaware of the possible interactions between birth control and certain supplements and herbal remedies. This could lead to a number of potential problems, including less effective birth control resulting in unintended pregnancies.

In this article, we will discuss the top supplements that could be a concern when taken with birth control.

What types of birth control can interact with medications or supplements?

Birth control refers to multiple methods of preventing pregnancy. There are many types of birth control, including:

• Oral contraceptives (also called “the pill”)
• Patches
• Vaginal rings
• Shots (also called “the depo shot”)
• Barrier methods (e.g, condoms)
• Non-hormonal vaginal gels (e.g., Phexxi, spermicides)
• Implants, such as Nexplanon
• Intrauterine devices (IUDs), such as Mirena
• Surgical operations (e.g., tubal ligation)

But not all birth control is the same. Some of these options have hormones — forms of estrogen, progesterone, or both — while others are hormone-free. Interactions depend on the contents of the birth control you are using. This means some medications and supplements may interact with some types of birth control but could be safe to use with other types.

Most combination birth control pills contain ethinyl estradiol (EE) — a type of estrogen — and progestin — a type of progesterone. Some birth control pills contain progestin only.  

Common progestins in birth control pills include norethindrone, norgestimate, levonorgestrel,  drospirenone, desogestrel, and gestodene.

If your birth control contains hormones, there’s a potential for drug interactions when taking other medications. This can include dietary supplements and herbal remedies.

Why do some supplements interfere with birth control?

Some supplements interfere with birth control because of the way they are metabolized (broken down) by the body. EE and most progestins in birth control pills are metabolized by a set of proteins called the CYP450 enzymes. These enzymes also help break down nearly half of the medications on the market as well as some common foods and dietary supplements.

Birth control pills and certain supplements can have a conflicting relationship with the same enzymes. This means that when taken together, some supplements could make this type of birth control less effective. This could lead to multiple problems, including more side effects and unintended pregnancies.

What are some common supplements that might interact with birth control?

There are a variety of herbs that have been used for centuries to treat various conditions. Herbs and supplements are not held to the same standards as prescription medications, which go through thorough human clinical trials before being FDA-approved. 

A common misconception is that because supplements are derived from a plant or other natural sources, they are safer than laboratory-made medications. But this is not true. While some research shows the beneficial effects of herbs and supplements on the body, there is still much more that needs to be done. This makes it difficult for many healthcare providers to make recommendations on when and how to use them.

There are several dietary supplements and herbal remedies that could interfere with oral birth control. Do not start any dietary supplements or herbal remedies without first discussing it with your healthcare provider and double-checking for drug interactions with your pharmacist.

St. John’s wort

St. John’s wort has been used for hundreds of years by people to help with depressed mood and anxiety. It’s also notorious for causing multiple drug interactions. Due to St. John’s wort’s influence on CYP450 enzymes, it can cause EE and some progestins to break down quicker in the body.

St. John’s wort can cause birth control pills to be less effective, potentially leading to unintended pregnancies. This interaction has also been found to cause irregular monthly bleeding and breakthrough bleeding.

Soy products 

Soy products contain high amounts of chemicals known as isoflavones. Isoflavones are a type of phytoestrogen — compounds found in plants and foods that act similar to estrogen in the body. Phytoestrogens have been studied for potential benefits in weight loss, osteoporosis, heart disease, and breast cancer. 

There aren’t many studies looking at potential interactions between isoflavones and hormonal contraception. There is concern though that phytoestrogens can potentially affect a woman’s hormone levels, and theoretically this can impact the estrogen in birth control. However, more studies are needed to determine the effects of phytoestrogens on birth control.

There are studies that show the potential effects of soy on a woman’s reproductive health.  For example, eating high amounts of certain soy products may affect a person’s fertility or typical menstrual cycle length or regularity.

A small case report of three people with irregular monthly bleeding and other reproductive health symptoms reported that lowering or eliminating soy from their diets helped relieve their symptoms. More research is needed to determine if this dietary change would have a similar effect on other people or affect people using hormonal birth control.

A review of available studies found that a soy-rich diet slightly lengthened monthly cycles but did not change the amount of estrogen in the body. It was not noted if the people in the various studies were using hormonal birth control. Occasional consumption of soy products should be fine, but due to the lack of strong research, it’s best to consult with your healthcare provider first.

Flaxseed and kudzu root also contain high amounts of isoflavones. Several other foods and herbs (including many meat and dairy alternatives) include lower amounts of these phytoestrogen compounds. Whether or not these foods and herbs affect hormonal birth control remains to be researched. 

It’s important to discuss your typical diet with your healthcare provider when taking hormonal birth control, so they can help you find an appropriate contraceptive option. 

Grapefruit juice 

Before slicing up your morning grapefruit, it is important to know that this citrus fruit could interfere with many medications. Eating grapefruit or drinking grapefruit juice could impact the amount of medication your body absorbs. 

When it comes to birth control, grapefruit has been shown to slow the breakdown of EE in your body. This means the EE from your birth control may hang around in your system longer. Consumption of grapefruit has also been linked with higher estrogen levels in post-menopausal people who were not taking any hormonal medications.

There is a possibility that grapefruit can interfere with the regulation of hormones, but more research is needed to determine this. Since grapefruit can also affect an enzyme that breaks down progestins, it is possible that it may also interact with this type of hormone as well.

Occasionally eating grapefruit should not cause any issues. Research is needed to thoroughly investigate the effects of grapefruit on hormonal birth control, but it is something to keep in mind if you eat a lot of grapefruit. 

Also, beyond grapefruit, citrus fruits — such as Seville oranges, pomelos, and tangelos — may have a similar effect on medications. 

Can activated charcoal cancel out the effects of birth control?

You may have heard of activated charcoal, as it has recently become a health fad. It has traditionally been used in emergency situations after consuming toxic or poisonous substances. Because of its ability to strongly bind to almost anything ingested, activated charcoal can render many medications ineffective.

This interaction can also apply to birth control. Depending on when activated charcoal is taken in relation to birth control pills, it can potentially make them ineffective. However, more research is needed to determine the extent of this effect. 

If you have used activated charcoal recently, contact your healthcare provider about this interaction and discuss other immediate options for contraception in the meantime.

If you suspect an interaction with your birth control, should you see your healthcare provider?

First and foremost, it is important that you are taking your birth control as directed by your healthcare provider. This will help maximize its effectiveness (between 91-99%, depending on the type). If you’ve missed doses, contact your healthcare provider or pharmacist for details on how to get back on track.

If you realize you’ve been taking medications or supplements that could interfere with your birth control, contact your healthcare provider immediately as you may need to use a backup method of contraception — like condoms or emergency contraception. 

As always, be sure to discuss all prescription medications, supplements, and herbal remedies you take regularly with your healthcare provider.

The bottom line

Hormonal birth control may have potential interactions with several foods and dietary supplements. While research is limited on these interactions, there is concern these combinations could cause more birth control side effects or make your contraception less effective. If you are interested in learning more about what you should and shouldn’t consume when taking birth control, talk to your healthcare provider.