Grapefruit and Birth Control Pills: Your Questions Answered
Medically reviewed by L. Anderson, PharmD. Last updated on Feb 20, 2018.
Have you received a medication at the pharmacy with a sticker that warns to avoid grapefruit or grapefruit juice? While this may seem like an unusual warning, it’s more common than you might think. In fact, grapefruit can interact with hundreds of medications. But is grapefruit affecting birth control a medical concern? Is grapefruit and pregnancy, and grapefruit and birth control effectiveness something you need to worry about?
Does Grapefruit Make Birth Control Less Effective?
Studies have shown that estrogens (contained in oral contraceptives or in hormone replacement therapy) are partially metabolized (broken down) by the intestinal cytochrome P450 3A4 (CYP3A4) enzymes. Grapefruit contains compounds known as furanocoumarins that block (inhibit) the CYP3A4 enzymes responsible for breaking down estrogens. When grapefruit and the pill are consumed, blood levels of estrogen may rise, resulting in a risk for new or worsened side effects such as breast tenderness, nausea, and changes in uterine bleeding.
A randomized, crossover, pharmacokinetic study of 13 healthy volunteers from Weber and colleagues evaluated the disposition of 17 alpha-ethinylestradiol after grapefruit juice consumption or herbal tea (containing 887 mg/mL of naringin).1 In contrast to herbal tea, grapefruit juice significantly increased peak plasma levels to 137% (Cmax) and the area under plasma concentration-time curve (AUC) from 0 to 8 hours to 128%. These levels are unlikely to affect the overall safety profile of estrogen; however, the authors suggested the clinical importance should be investigated.2,3
Does Grapefruit Make the Pill Less Effective?
Women may ask “Does grapefruit or grapefruit juice affect birth control?”. Estrogen levels increase when oral hormones like estrogen, contained in the birth control pill, are taken. Higher estrogen levels should not lower the effectiveness of the birth control but may lead to birth control interactions like greater estrogen side effects like breast tenderness or nausea. Grapefruit and grapefruit juice and birth control combined decrease the activity of the enzymes that break down estrogen, leading to the higher blood levels of estrogen.
However, some medications can increase (induce) the activity of the CYP3A4 enzyme, boost estrogen drug metabolism and possibly lower the effectiveness of the birth control pill. Inducers of CYP3A4, such as the herbal supplement St. John's Wort (Hypericum perforatum) used for depression, phenobarbital and carbamazepine (and other anticonvulsants), and rifampin used to treat tuberculosis -- among many others drugs -- may reduce plasma concentrations of estrogens. Reduced blood levels of estrogens may result in a decrease in birth control effectiveness and/or changes in bleeding. Alway have your pharmacist complete a screen for birth control drug interactions each time you start or stop any new medication. You may need to use a back-up method of birth control, such as a condom.
Tip: Check for pill interactions with the Drugs.com Interaction Checker
Can I Drink Grapefruit Juice with Birth Control?
- If you eat grapefruit or drink grapefruit juice, be sure to tell your doctor, pharmacist or other health care provider. Let them know how much grapefruit you consume each day. In most cases, you should be able to continue consuming grapefruit with birth control.
- While grapefruit normally will not lower the effectiveness of the birth control pill, you may need to discuss the possibility of greater estrogen side effects with your doctor.
- If you must avoid grapefruit juice with your medicine, check the labels of other fruit juices to see if they contain grapefruit juice.
- Seville oranges (often used in orange marmalade), pomelos, limes, and tangelos (a cross between tangerines and grapefruit) may have the same effect as grapefruit juice. Do not eat or drink those fruits if your medicine interacts with grapefruit juice.3 Pregnancy is not normally a risk with grapefruit, but higher estrogen levels may be.
- Always have your pharmacist perform a drug interaction check with all of your medications, including over-the-counter (OTC) medications, vitamins, and herbal supplements, to rule out an interaction before you combine them. Do not stop medications on your own without checking with your healthcare provider.
Is There an Interaction If I Take Grapefruit and My Birth Control at Different Times?
Does eating grapefruit affect birth control? As reported in a study by Monroe, et al.,4 taking medications and grapefruit or grapefruit juice at different times may not lessen the possibility for an interaction. The CYP450 enzymes, found in the intestine and the liver, can stay blocked after eating or drinking grapefruit -- sometimes for more than 24 hours.6 Consumption of a single 6 oz. glass of grapefruit may result in higher estrogen levels, but daily use of grapefruit may lead to a more significant, unpredictable effect. Even drugs that are only given once a day cannot be separated from the grapefruit effect. If you need to avoid grapefruit while you are taking a certain drug, it is best not to consume grapefruit at all, either the juice or whole fruit.3
Does Orange Juice Affect Birth Control?
Most other fruits like orange juice or cranberry juice are fine to eat or drink if you take birth control. However, some other citrus fruits may affect metabolism similar to the grapefruit. The seville orange (often used in marmalades), the pomelo, tangelos (a cross between tangerines and grapefruit), and limes also contain furanocoumarins that may cause the same interactions as grapefruit, leading to higher estrogen levels. Higher estrogen levels won’t change the effectiveness of the pill but may lead to side effects like breast tenderness or nausea. Remember, this effect is variable and may not be clinically significant in every person.
Orange juice can have some drug interactions. The non-sedating antihistamine Allegra (fexofenadine) has been shown to interact with certain fruit juices, including grapefruit juice, orange juice and apple juice, and may decrease the levels of fexofenadine in the body. Fexofenadine should be taken with water; do not drink large amounts of grapefruit, orange, or apple juice.
Can Grapefruit Cause Serious Side Effects When Mixed With Birth Control?
More rare but serious side effects have been described when estrogen was combined with large quantities of grapefruit. A 2009 case report in The Lancet described a women who rarely ate grapefruit, but started an aggressive weight-loss diet plan, including 225 grams of grapefruit every morning (roughly one grapefruit). The woman also used a low-dose combined oral contraceptive containing drospirenone and ethinyl estradiol (an estrogen) for one year. Three days after starting the grapefruit diet, she experienced an acute venous thrombosis (a serious blood clot in a deep vein of the leg) and the authors theorize it may have been in part due to the interaction of the grapefruit, enzyme inhibition, and the estrogen in the birth control pill leading to enhanced risk of a blood clot.7
Does Grapefruit Affect Endogenous Estrogen Levels in the Body?
Elevating levels of naturally occurring estrogen in the body (endogenous estrogen) by consuming grapefruit could theoretically increase the risk for breast cancer. A 2013 pharmacokinetic study in 59 women found that eating grapefruit can increase levels of endogenous estrogen (but not grapefruit juice and estrogen).4 The results showed that whole grapefruit intake had significant effects on endogenous estrone-3-sulfate. Peak effects were seen at 8 hours, increasing by 26% from baseline. No changes in mean estrone or estradiol with whole fruit intake were observed. In contrast, fresh grapefruit juice, bottled grapefruit juice, and grapefruit soda intake all had significant lowering effects on estradiol. The authors conclude that the findings suggest an important interaction between grapefruit intake and endogenous estrogen levels and suggest further research is warranted. However, other studies have found a protective effect of grapefruit and citrus juice with regards to breast cancer risk, and risk of other cancers.8,9
Does Cranberry Juice Affect Birth Control?
Cranberry juice has not been shown to interact with birth control, but the blood thinner (anticoagulant) warfarin has been shown to have an interaction with cranberry. Ask your doctor before using warfarin together with cranberry. Using these medications together can cause you to bleed more easily. You may need to have more frequent blood tests or a dose adjustment.
How Do Birth Control Pills Work?
Birth control pills work by preventing fertilization of the woman's egg with the man’s sperm. Birth control pills contain synthetic estrogens and progestins that prevent an egg from being released in the middle of a woman’s cycle and stop ovulation (the release of the egg). The pill also helps to make an unfavorable environment for an egg to become fertilized and grow, by thickening the mucus on the cervix.10
What Types of Birth Control Are There?
Many options are available for birth control:10
- Birth control pills, also known as oral contraceptives
- Other forms of hormonal birth control (i.e., the birth control shot or implant, vaginal ring, birth control patch, intrauterine device or IUD)
- Non-hormonal birth control options (condom, sponge, spermicide, cervical cap, diaphragm, copper IUD, natural family planning, abstinence)
- Permanent birth control options (tubal ligation, tubal implants, vasectomy)
- Emergency birth control options (Plan B One Step, Next Choice, Ella, copper IUD)
Learn More: See the Drugs.com Birth Control Guide
List of Popular Birth Control Pills
There are many options for birth control pills. Some of the more commonly used birth control pills prescribed in the U.S. include:
- Lo Loestrin Fe (ethinyl estradiol / norethindrone systemic)
- Sprintec (ethinyl estradiol / norgestimate systemic)
- Lutera (ethinyl estradiol / levonorgestrel systemic)
- Yaz (drospirenone / ethinyl estradiol systemic)
- Ortho Tri-Cyclen Lo (Ethinyl Estradiol and Norgestimate)
- Yasmin (drospirenone and ethinyl estradiol)
- Aviane (ethinyl estradiol / levonorgestrel systemic)
- Tri-Sprintec (norgestimate and ethinyl estradiol tablets)
How Effective is the Birth Control Pill?
Even if you take the pill exactly the way you are supposed to, you still have a small chance of getting pregnant. The pill has a less than 1% failure rate (meaning less than 1 out of 100 women unintentionally become pregnant) if the pill is always taken correctly. For women who miss their pills, the failure rate goes up to roughly 9%, or 9 out of 100 women become pregnant unintentionally. Vomiting or diarrhea for 48 hours, or being extremely overweight may also lower the effectiveness of the pill. Also, certain drug interactions can make the pill less effective, so it’s always important to have your pharmacist check for interactions with birth control or any new prescription.
The most effective forms of birth control are complete abstinence from sex, the IUD, the implant, or sterilization. All of these forms of birth control are about 99% effective at preventing pregnancy.10
Learn More: All About Birth Control Pills
Drugs That Interact With Birth Control
It’s not just grapefruit that may have an effect with estrogen. Many drugs may alter enzyme activity and may increase estrogen levels and side effects, or decrease estrogen levels and birth control effectiveness. Always check with your doctor or pharmacist for clinically significant drug interactions.
Some drugs may lower the 3A4 enzyme activity (enzyme inhibitors) and can increase estrogen levels and lead to worsened side effects. However, the interaction can be variable based on the amount of the CYP enzyme in each person’s intestine and the drug consumed. Example of drugs that inhibit 3A4 enzyme activity include:
- clarithromycin (Biaxin, Biaxin XL)
- certain azole antifungals like voriconazole
Some drugs may increase the enzyme activity (inducers) and can lower the effectiveness of oral contraceptive:
- certain anti-seizure medications or anticonvulsants (e.g., carbamazepine, eslicarbazepine, oxcarbazepine, phenobarbital, phenytoin, and primidone)
- the antifungal medicine griseofulvin
- St. John’s Wort, an herbal supplement
- barbiturates like phenobarbital
- certain HIV medications like ritonavir
- the tuberculosis (TB) antibiotics rifampin or other rifamycins (rifabutin and rifapentine)
This is not a complete list of all drug interactions with birth control. Always check with your doctor or pharmacist for possible drug interactions with prescription, over-the-counter, or herbal supplements. You may need to use an additional or alternative form of birth control while using the enzyme inducer and for one cycle after you stop taking the inducer.
Learn More: Does Birth Control Interact With Alcohol?
Grapefruit and grapefruit juice can react with hundreds of prescription medications. In fact, compounds in grapefruit have an inhibitory (blocking) effect on the intestinal cytochrome P450 3A4 (CYP3A4) system and may lead to higher blood concentrations of over 60% of orally administered drugs. Combining grapefruit and oral contraceptives that contain estrogen, or grapefruit and hormone replacement therapies may lead to higher estrogen levels.
Clinically relevant grapefruit juice-drug interactions can occur, so always check with your doctor for the impact of grapefruit with your drugs. Alway have your pharmacist complete a drug interaction screen each time you start or stop any new medication. Iff there is a recommendation to avoid grapefruit juice, remember you need to avoid it completely when you are taking the medication, not just when you swallow your pill.
- Birth Control Pills
- Birth Control Pills - Benefits vs Risks & Side Effects
- Birth Control Pills - Periods
- Birth Control Pills and Breakthrough Bleeding
- Emergency Contraception
- Hormonal Birth Control (Non-Pill Options)
- Missed taking your birth control pill?
- Non-hormonal Birth Control
- Permanent Birth Control
- Weber A, Jäger R, Börner A, et al. Can grapefruit juice influence ethinylestradiol bioavailability? Contraception. 1996;53:41-7. Accessed February 18, 2018 at https://www.ncbi.nlm.nih.gov/pubmed/8631189.
- Drug Interactions Checker. Professional Interaction data. Ethinyl estradiol and Alcohol / Food Interactions. Accessed February 19, 2018 at https://www.drugs.com/food-interactions/ethinyl-estradiol.html?professional=1
- Grapefruit Juice and Some Drugs Don't Mix. U.S. Food and Drug Administration (FDA). Updated July 2017. Accessed February 20, 2018 at https://www.drugs.com/fda-consumer/grapefruit-juice-and-medicine-may-not-mix-208.html
- Monroe KR, Stanczyk FZ, Besinque KH, et al. The Effect of Grapefruit Intake on Endogenous Serum Estrogen Levels in Postmenopausal Women. Nutr Cancer. 2013; 65(5): 644–652. Accessed February 20, 2018 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5796810/
- Schubert W, Eriksson U, Edgar B, et al. Flavonoids in grapefruit juice inhibit the in vitro hepatic metabolism of 17 beta-estradiol. Eur J Drug Metab Pharmacokinet. 1995;20(3):219-24. Accessed February 20, 2018 at https://www.ncbi.nlm.nih.gov/pubmed/8751044
- Bailey DG, Malcolm J, Arnold O, et al. Grapefruit juice-drug interactions. Br J Clin Pharmacol 1998;46:101-110. Accessed February 20, 2018 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1873672/
- Grande LA, Mendez RD, Krug RT, et al. Attention--grapefruit! Lancet. 2009 Apr 4;373(9670):1222. Accessed February 19, 2018 at http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)60289-0/fulltext
- Cirmi S, Maugeri A, Ferlazzo N, et al. Anticancer Potential of Citrus Juices and Their Extracts: A Systematic Review of Both Preclinical and Clinical Studies. Frontiers in Pharmacology. 2017;8:420. doi:10.3389/fphar.2017.00420. Accessed February 20, 2018 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491624/
- Kim EH, Hankinson SE, Eliassen AH, at al. A prospective study of grapefruit and grapefruit juice intake and breast cancer risk. Br J Cancer. 2008;98:240–241. Accessed February 20, 2018 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2359690/
- Planned Parenthood. Birth Control Pill. Accessed February 20, 2018 at https://www.plannedparenthood.org/learn/birth-control/birth-control-pill
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.