The Biggest Birth Control Myths, Debunked

Taking on some of the most common questions (and myths) about birth control

There’s a lot of information out there about birth control. We hear it from our friends, our siblings, our doctors, our mothers, and our internet searches. While much of this information is good, some of it is not entirely true or not true for everyone — and some of it is completely bunk.

Our bodies are complex, so it’s hard to label every claim about birth control as either true or false. Still, we think it’s important to challenge and investigate claims we’ve heard to see which are backed up by evidence, and which aren’t! Here are some of the most common questions we’ve asked and been asked about birth control, and what the real answers are.

Can I still get pregnant while on birth control?

Technically, yes, this one’s true: You can still get pregnant while on birth control. The likelihood of getting pregnant while on birth control depends on which method you’re using, and whether you’re using it perfectly (you’ll sometimes hear this called “perfect use.”) Think of perfect use as the condom that stays in place, doesn’t tear, and doesn’t leak.

If you’re using birth control like the pill, IUDs, or contraceptive implants — methods rated as highly effective, especially for typical use and not just perfect use — it’s unlikely you’ll get pregnant. If you want to decrease your odds of pregnancy even further, you can combine methods, for example by adding condoms and/or pulling out to a hormonal method like the pill, the patch, the shot, or an IUD.

Does the pill protect me from sexually transmitted infections?

No, hormonal birth controls like the pill do not protect against sexually transmitted infections. The only way to protect against STIs and STDs during sexual contact is to use a condom.

According to the CDC, using condoms consistently and correctly is the best way to protect against sexually transmitted infections like HIV and other STDs.¹ They’re most effective against diseases that are transmitted through bodily fluids, like chlamydia and gonorrhea. Other STDs are transmitted just by skin-to-skin genital contact, and this can still occur even with even a properly worn condom. Although condoms do offer some protection against these, you’re not as protected against STDs like genital herpes, or human papillomavirus (HPV).

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Is the pill effective immediately after you begin taking it?

No, the combination hormonal birth control pill can take up to seven days to start preventing pregnancy.² So, you should plan on using another form of birth control if you’re having sex during that time. It depends when during your cycle you start taking it, though — if you start during your period (specifically, within five days of the first day of your period), you’ll be protected right away.² And if you’re taking the pill for other benefits, like to relieve acne,³ it can take as long as three cycles (up to three months) to see those benefits as your body’s hormones adjust to new levels.

Will birth control make me gain weight?

The answer to this question is no, for most types of contraceptives at least. Studies of weight gain and hormonal contraceptives dating back decades find that birth control options like the pill, IUD, ring, and patch don’t cause weight gain. But two kinds of hormonal birth control, the shot, also called Depo-Provera, and the implant, can cause some people, but not all, to gain weight.

That birth control will make you heavier is a super commonly held belief, and it’s a side effect many hormonal contraceptive users attest to. In a survey of more than 2,500 women, 69% reported having experienced at least one side effect; of them, 55% reported weight gain and 41% said it was noteworthy enough that they stopped using the contraceptive because of it.⁴

Yet when researchers look for a direct effect of most hormonal contraceptives on weight gain, they can’t find it. In 2014, researchers reviewed 49 clinical trials that tested the idea, and found no consistent evidence that the combined contraceptive pill causes weight gain.⁵

What gives? Some researchers suspect temporary water retention is to blame, or possibly an increase in appetite.⁶ But these theories don’t have much evidence behind them yet — more research is needed to figure out if there is really a link and why.

There is evidence that the birth control shot and the implant can lead to weight gain for some people. A 2019 review of research on Depo-Provera reports a number of studies found weight gain to be a side effect.⁷ A 2014 study of both Depo and the implant also found that users of those two methods gained more weight than those using hormonal and copper IUDs (though  the implant showed no evidence of increased weight gain after adjusting for age and race.)⁸

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It may be that only some people gain weight when using the shot or implant, though. One 2020 study in the journal Contraception notes that some genetic variants might predispose people to weight gain when using the implant.⁹ A 2009 study of Depo-Provera users also found that some people gained significantly more weight than others after starting the contraceptive.¹⁰

Those two methods aside, the evidence shows the pill, IUDs and other common forms of contraception won’t cause weight gain.

Will using birth control prevent me from getting pregnant in the future? Will it cause infertility?

No! Reversible forms of birth control do not make you infertile or decrease your chances of having a baby someday. If you’re using hormonal birth control like oral contraceptives, your fertility should return to normal levels within 2–6 months, although some people can get pregnant immediately.⁷ In fact, one study found that women coming off the pill after more than two years of use were actually more likely to get pregnant than compared to their peers who had used only barrier methods before trying to get pregnant.⁷

Read more: Can birth control cause infertility?

Will birth control “unbalance” my hormones?

No, in fact, the opposite is typically true! Hormonal birth control can help regulate the extreme changes in hormone levels that occur during your menstrual cycle, which, for some people, is a good thing. Regulating your hormones out can help with heavy or irregular bleeding, cramping, and more. Hormone levels naturally fluctuate (“balanced” hormones isn’t really a thing), and they continue to fluctuate even when you’re on hormonal birth control.

Why take birth control if you’re not sexually active?

There are a number of benefits to birth control beyond preventing pregnancies, and many people take hormonal contraceptives for other reasons. Because hormonal birth control can help to even out hormonal fluctuations, it can help with things like PMS symptoms, irregular bleeding, hirsutism, and even acne.⁹

Will birth control make me depressed?

This one depends on your biology. Certain methods of birth control are associated with higher risk of depression, especially in adolescents.^10-11 Estrogen and progesterone, two of the key hormones in many hormonal birth controls, affect your mood. But that doesn’t automatically mean birth control will make you depressed. For some people, hormonal birth control can actually improve mood by keeping cycle-related irritability and moodiness in check. But for others, it can have the opposite effect: Mood changes are one of the most frequently cited reasons that people stop taking birth control.

This is a topic that desperately needs more study. We hope you’ll join us here at adyn as we develop a more complete data set on birth control side effects like depression, in search of more inclusive scientific conclusions!

Will my IUD fall out?

No, it’s not likely that your IUD would fall out — though it is possible. The IUD expulsion rate can range from 2–10% depending on age and how long the device is left in place.^12-14 Some researchers have found it tends to be higher for teens and for people who have had one in place for longer. But a lot of studies have reported conflicting results, so more research is needed.

Be sure to occasionally check that your IUD strings are still in place, and if anything ever seems amiss or if you know your IUD has fallen out, contact your doctor right away and use alternative forms of contraception to be safe.

Are all birth control methods effective?

All forms of birth control, when used correctly, do something to reduce your risk of pregnancy. But not all forms of birth control are equally effective. We only recommend using contraceptives rated : 98% effective for preventing pregnancy with perfect use. Birth control shots, patches, pills, rings, implants, and IUDs all fall into this category.

Do you still need birth control if you practice fertility awareness?

Yes. Fertility awareness is not considered an effective form of birth control. We recommend switching to or supplementing with another method if you don’t want to get pregnant.

That said, if you’re ovulating (so, not taking hormonal birth control), it can be helpful to know which times of the month you’re most and least likely to get pregnant. Most ovulating people are at their most fertile in the five days before ovulation until one day after. Ovulation occurs around day 14 of your menstrual cycle, counting from when your period starts. That means you can decrease your chances of pregnancy by avoiding penis-in-vagina sex on days 10 through 15 of your cycle.

Do you still need birth control if your partner pulls out?

Yes. The pull-out method is not considered an effective form of birth control, and you should supplement it with additional contraceptives if you don’t want to get pregnant. Pulling out, also called the “withdrawal method,” is only about 82% effective at preventing pregnancy.¹⁵ That means nearly 1 in 5 couples using that strategy will get pregnant every year. The reason it’s not effective is twofold: it’s hard to actually achieve, and even when your partner pulls out on time, pre-ejaculate can contain sperm.¹⁶

Will all birth control methods affect my hormones?

No, not all birth control methods affect your hormones. Although some birth control options use hormones to prevent your body from ovulating, others use physical barriers and other methods. Internal and external condoms (aka “male” and “female” condoms), and other barrier methods won’t affect your hormones, nor will spermicidal gels. That said, these methods aren’t as effective as hormonal birth control methods like the pill, patch, ring, implant, or hormonal IUDs. One notable highly effective, non-hormonal option is the copper IUD, which works by preventing sperm from swimming properly.¹⁷

Any other birth control myths you want fact checked? Tweet at us with your question or a myth that needs busting!

This article was originally published on January 24, 2022 and updated on May 9, 2024.