Grapefruit and Birth Control Pills: Your Questions Answered
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.
If you drink grapefruit juice with your birth control can it lower its effectiveness? Can you get pregnant if you drink grapefruit juice with your birth control pill? Let's look into this a little further.
Grapefruit and birth control
Combination oral contraceptives, the pill that most women use, contain both estrogen and progestins, the female hormone. Theoretically, consuming grapefruit with birth control pills might increase the estrogen levels in your blood. This shouldn't lower the effectiveness of your birth control, but it might increase the chances for side effects like breast tenderness, nausea, changes in uterine bleeding, blood clots, or breast cancer. Many of these side effects have not been proven with grapefruit, but theoretically may occur.
- 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. These enzymes are commonly found in our bodies and affect many different types of drugs.
- Grapefruit contains compounds known as furanocoumarins that block (inhibit) these 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.
One study looked at how grapefruit juice (containing 887 mg/mL of naringin) affect estrogen levels and compared this to the effect of drinking herbal tea.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%. This means that higher levels of estrogen were found in the body. A possible explanation is that grapefruit juice slows down the break down of ethinylestradiol. 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?
Probably not. Estrogen levels increase when the combined oral birth control pill is taken. Higher estrogen levels (as seen with the study above) should not lower the effectiveness of the birth control. However, birth control drug interactions or greater estrogen side effects like breast tenderness or nausea might occur. Grapefruit, 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 break down and possibly lower the effectiveness of your birth control pill. Inducers of CYP3A4 may reduce plasma concentrations of estrogens. Reduced blood levels of estrogens may result in a decrease in birth control effectiveness and changes in monthly bleeding.
Examples of drugs that may decrease birth control effectiveness include:
- the herbal supplement St. John's Wort (Hypericum perforatum) used for depression
- phenobarbital, carbamazepine (and other anticonvulsants)
- rifampin used to treat tuberculosis
But there are others, so always have your pharmacist or doctor check for birth control drug interactions each time you start or stop any new medication. This includes over-the-counter drugs, herbals, dietary supplements and vitamins. You may need to use a back-up method of birth control, such as a condom and spermicide, to help prevent pregnancy. Do not stop medications on your own without checking with your doctor or other healthcare provider.
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 without any issues.
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, don't forget to check the labels of other fruit juices to see if they contain grapefruit juice.
Is there an interaction if I consume grapefruit and my birth control at different times?
Does when you eat or drink grapefruit affect your birth control? As reported in a study by Monroe4 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?
Still worried about how to get your vitamin C? 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.3
- Higher estrogen levels won’t change the effectiveness of the pill but may lead to side effects like breast tenderness or nausea.
- This effect is variable and may not be clinically significant in every person.
However, orange juice can have some other 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. Lower levels may reduce the effectiveness of the antihistamine.
Fexofenadine (Allegra) should be taken with water; do not drink large amounts of grapefruit, orange, or apple juice with this medicine. Allegra ODT can be taken with or without water.11
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 (a progestin) 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 natural 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 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, but whether this affect is clinically important in women was not proven. It's important to know that other studies have found a protective effect of grapefruit and citrus juice with regards to breast cancer risk, and the risk of other cancers, as well.8,9
Does cranberry juice affect birth control?
Cranberry juice has not been shown to interact with birth control, but the blood thinner warfarin (an anticoagulant) 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 warfarin blood tests or a change in dose.
How do birth control pills work?
Birth control pills work by preventing fertilization of the woman's egg with the man’s sperm. Combined oral contraceptives contain the man-made hormone estrogen and progestin, and prevent an egg from being released in the middle of a woman’s cycle (stops ovulation). 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, no sexual intercourse)
- Permanent birth control options (tubal ligation, tubal implants, vasectomy)
- Emergency birth control options (Plan B One Step, Next Choice, Ella, copper IUD)
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
Related: 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 increase estrogen levels and side effects, or decrease estrogen levels which can lower birth control effectiveness. Always check with your doctor or pharmacist for clinically significant drug interactions.
Some drugs known as enzyme inhibitors may lower the 3A4 enzyme activity, 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)
- antifungals like voriconazole
- ritonavir (an HIV medicine)
Some drugs known as enzyme inducers may increase the enzyme activity and lower the effectiveness of an oral contraceptive. These include:
- some 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 (back-up) form of birth control like condoms 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 block intestinal enzymes and may lead to higher blood concentrations of over 60% of all orally administered drugs.
Combining grapefruit and oral contraceptives that contain estrogen, or grapefruit and hormone replacement therapies may lead to higher estrogen levels. Higher estrogen levels might cause side effects like breast tenderness, nausea, and changes in uterine bleeding. More serious side effects like blood clots or an increased risk of breast cancer are theoretical concerns, too (but not proven).
Clinically relevant drug interactions with grapefruit juice can occur, so always check with your doctor for the impact. Have your pharmacist complete a drug interaction screen each time you start or stop any new medication. If there is a recommendation to avoid grapefruit juice, it's best to avoid it completely when you are taking the medication, not just when you swallow your pill.
- Birth Control Pills
- Birth Control Pills - Periods
- Birth Control Pills and Breakthrough Bleeding
- Birth Control Pills: Benefits, Risks and Side Effects
- Emergency Contraception
- Emergency Contraceptives Available in the U.S.
- Hormonal Birth Control (Non-Pill Options)
- Missed taking your birth control pill? Here's what to do next
- 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 March 9, 2020. doi:10.1016/0010-7824(95)00252-9
- Drug Interactions Checker. Professional Interaction data. Ethinyl estradiol and Alcohol / Food Interactions. Accessed March 9, 2020 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 March 9, 2020 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 March 13, 2020. doi: 10.1080/01635581.2013.795982
- 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 March 13, 2020. DOI: 10.1007/BF03189673
- Bailey DG, Malcolm J, Arnold O, et al. Grapefruit juice-drug interactions. Br J Clin Pharmacol 1998;46:101-110. Accessed March 13, 2020. DOI: 10.1046/j.1365-2125.1998.00764.x
- Grande LA, Mendez RD, Krug RT, et al. Attention--grapefruit! Lancet. 2009 Apr 4;373(9670):1222. Accessed March 13, 2020. DOI: 10.1016/S0140-6736(09)60289-0
- 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. Accessed March 9, 2020. doi:10.3389/fphar.2017.00420.
- 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 March 13, 2020. https://doi.org/10.1038/sj.bjc.6603880
- Planned Parenthood. Birth Control Pill. Accessed March 9, 2020 at https://www.plannedparenthood.org/learn/birth-control/birth-control-pill
- Allegra Product Label. Sanofi-Aventis. Accessed March 9, 2020 at https://www.drugs.com/pro/allegra.html
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.