Grapefruit may interact with birth control and hormones by affecting a certain enzyme in the body. However, there is limited scientific research proving a link.
However, it is unclear to what extent grapefruit can interfere with hormonal birth control. The response may vary from person to person.
This article will discuss how grapefruit affects birth control and hormones, as well as other factors that may impact contraceptives.
Grapefruit may affect birth control, but there is limited research showing a direct interaction between grapefruit and contraceptives.
It is possible that grapefruit may also inhibit the body’s ability to break down the hormones in some types of birth control. This can increase the chance of side effects.
However, few studies have proven this. An older 1996 study involving 13 volunteer participants found that grapefruit juice increased the amount of an estrogen drug, but this was a very small sample group.
Larger trials that also track the rates of birth control side effects are necessary to determine if grapefruit has a significant impact on health.
Certain compounds in grapefruit
The CYP3A4 enzyme can play a
However, it is important to note that people have varying amounts of CYP3A4 in their intestines. Some have more than others, meaning grapefruit can have a bigger or smaller effect on different individuals.
The results of the 1996 study suggest this is true for the metabolism of ethinylestradiol, which is a synthetic form of estrogen present in some types of birth control. The peak concentration of this drug in the participants’ blood spanned 64–214%, showing a range of responses even when the volunteers all took the same dose.
So, if grapefruit can significantly affect how the body processes hormonal birth control, it may be hard to predict how much.
Progesterone-only birth control delivers the progestin hormone without any estrogen. Examples of progesterone-only birth control
Even though these forms of contraception do not contain estrogen, grapefruit may still affect them. As with estrogen, the body uses the CYP3A4 enzyme to metabolize progestin, meaning that interference could increase progesterone levels.
Again, though, more research on this is necessary.
In addition to affecting the hormones in birth control, grapefruit may also affect hormones the body makes on its own.
Whole grapefruit had no effect on some other types of estrogen. However, fresh and bottled grapefruit juice, as well as grapefruit soda, decreased an estrogen known as estradiol.
More research can help determine if and how grapefruit affects reproductive hormones.
One of the main factors that can interfere with hormonal birth control is how a person uses it. Forgetting to take pills, receiving a late dose, or in the case of the mini pill, taking the drug at inconsistent times of the day, can all make these forms of birth control less effective.
Similarly, vomiting and diarrhea for more than 48 hours can affect whether birth control works, as this may reduce how much of the drug is in the body.
There are also medications that may reduce the effectiveness of birth control, including:
- certain antibiotics, such as rifampicin
- the antifungal drug griseofulvin
- some HIV medicines
- some epilepsy medicines
- St. John’s wort
People taking these medications need to use an additional barrier method of contraception to prevent pregnancy.
Some birth control methods can deliver progestin hormones, or a combination of estrogen and progestin hormones. Grapefruit may impact how the body processes these hormones.
Grapefruit can interfere with some medications by inhibiting the CYP3A4 enzyme. This enzyme helps process estrogens and some progestins, and so plays a key role in hormonal drug metabolism.
If something hinders the CYP3A4 enzyme, it may impact how well the body breaks down hormones, leading to higher hormone concentrations. However, people can have different responses to grapefruit, so it is unclear if this is a major concern for most people.
People who are concerned about drug interactions with their birth control, including from grapefruit, can speak with a doctor or sexual health professional.