You might have a friend who swears that birth control made her gain weight. Is she right? For many women, the answer can be the difference between trying birth control or not.
Can birth control make you gain weight?
As of now, doctors say no, birth control should not cause weight gain. That's because when you look at the years and years of research that's been done, there isn't enough evidence to say birth control causes weight gain. However, birth control can cause bloating and water retention.
What makes this debate even more messy (and slightly unfair!) is that people may simply gain weight as they grow older, or as their situation changes.
Why the truth matters when it comes to weight gain
Investigating whether birth control makes you gain weight is no easy task. Researchers have been studying it over two decades and counting, with thousands of women participating. It's a question the medical community takes very seriously, because they know it's a concern for women who want to take birth control.
Can we trust the research on weight gain
Researchers have examined the different kinds of birth control, from pills to the patch to the shot, to really see if the women participating in various trials showed enough weight gain to make the results significant.
Their research involved the 2 major types birth control: 1. Birth control with both progestin and estrogen (combination methods). Examples include most birth control pills and the birth control patch. 2. Birth control with progestin but no estrogen (progestin-only methods). Examples include the mini-pill (a birth control pill) or the Depo-Provera™ shot.
The facts: Birth control and weight gain
We can summarize what the researchers found:
For combination birth control, there's not enough evidence to say it causes weight gain.
For progestin-only birth control, there's little evidence of effects on weight. But they did find some evidence of changes in weight for women who used the Depo Provera shot.
Why it seems birth control causes weight gain
So, where does the stigma of birth control and weight gain come from?
Bloating side effect
First, it's possible to feel like you're gaining weight during the first few weeks or months of a new birth control method, even if you're not. This is because the hormones in birth control may cause fluid or water retention, which can lead to bloating as a potential side effect and definitely feel similar to gaining weight.
Water weight can cause the number on the scale to go up while your body composition (aka the amount of body fat you have and where it's located) remains the same.
Side note: Just because bloating isn't the same as gaining weight, it doesn't mean it's a fun symptom to have. If your bloating is severe or doesn't go away, you should talk to your doctor about it.
Body weight changes over time
Second, whether you're taking birth control or not, it's normal for body weight to fluctuate. Plus, humans tend to gradually gain weight—an average of little over a pound a year—throughout most of their adult lives.
You may gain weight around the time you start a new birth control without the two being connected.
The research says that it's unlikely, but not impossible, for birth control to make you gain weight. Still, you shouldn't brush it off if you feel like your birth control is causing negative side effects. Your doctor should be able to help you find other options that may work better for you.
What the doctors say about birth control and weight gain
The question about birth control and weight gain is complicated. When your doctor researches this, they make their decisions based on current research and what they've observed in their own patients.
Most doctors agree that if there is a risk of weight gain with hormonal birth control, the effect is probably small.
The one exception to this is the Depo-Provera hormone shot, which has been linked to weight gain in more than one study. Some doctors believe the reason Depo-Provera can cause weight gain is because it may activate signals in the brain that control hunger. (However, this definitely doesn't mean that everyone who gets the birth control shot will gain weight.)
Why birth control might cause weight gain
Hormonal birth control works because it prevents ovulation, helps keep sperm from making it to the uterus, and makes implantation unlikely—all things that have to happen for you to get pregnant. It does this by adding hormones to your body that cause these changes.
There are two types of hormonal birth control:
Combined hormonal contraceptives contain estrogen and progestin. This category includes:
Most birth control pills (Such as Apri, Aviane, Sprintec, Mircette, Ortho-Cyclen, and Yaz)
The patch (Xulane)
The ring (Annovera, NuvaRing)
Progestin-only contraceptives contain (you guessed it) only progestin. This group includes:
The implant (Nexplanon)
Most IUDs (Mirena, Kyleena, Liletta, and Skyla. The copper IUD doesn't contain any hormones, so it's not a part of this list.)
The shot (Depo-Provera)
Some birth control pills, such as the minipill (Camila, Micronor, Errin, Jolivette)
The hormones in birth control are great at preventing pregnancy, but they can sometimes cause other changes in your body too. These can include acne, headaches, breast tenderness, changes to your sex drive, irregular periods , and nausea.
Most side effects should go away within a few months, as your body gets used to the added hormones. You should let your doctor know if your side effects don't go away.
Why is weight gain a common concern
The stigma surrounding birth control and weight gain probably started decades ago, when symptoms used to be more severe than they are now.
When birth control was first available in the 1950s, it contained much higher levels of hormones. Think: 150 milligrams of estrogen instead of the 20 to 50 milligrams used in most birth control doses today.
When you're adding more hormones to your body, they're going to make bigger changes. That's why symptoms like bloating, increased appetite, and even weight gain, were more common in decades past.
Since then, doctors have worked consistently to find the minimum hormone dosage that can prevent pregnancy with as few potential side effects as possible.
Weight gain vs. specific birth control methods
Most birth control studies agree that hormonal birth control isn't likely to cause weight gain. But the actual evidence is different for each specific type of birth control.
Here's what researchers have observed so far:
Myth vs. fact: The pill causes weight gain
Unlike other birth control methods, there's been a good amount of research on birth control pills over the years. Several studies have found that, overall, women taking birth control pills (combined estrogen and progestin) don't gain weight any faster than women using non-hormonal birth control. Women on the pill also didn't notice any body fat changes compared to women not using hormonal birth control.
Myth vs. fact: The ring causes weight gain
Like the pill, the ring isn't likely to cause any increases in weight gain or body fat. This 2006 study published in the scientific journal Human Reproduction looked at 983 women either taking the pill or using NuvaRing. There was no difference in weight gain or body composition between the two groups.
Myth vs. fact: The patch causes weight gain
The birth control patch is applied to the skin and delivers the two hormones progestin and estrogen to the body. Some women are afraid that the patch could make them gain weight. There have been trials done in the past where a woman's weight was measured while on the patch. Researchers reviewed these studies and came to the conclusion that birth control patches should have no major effect on weight.
Myth vs. fact: The implant causes weight gain
This 2016 study observed no noticeable difference in weight gain between people with the implant versus people using a copper IUD. (Birth control studies often use the copper IUD as the comparison group because it doesn't have any hormones.)
Likewise, this 2017 study compared women with the implant and women with a placebo implant (one that didn't contain any hormones). There was no evidence of extra weight gain in the women with the implant.
But the authors note that expecting to gain weight on birth control may make you more likely to feel like you're gaining weight.
Myth vs. Fact: The IUD causes weight gain
The evidence on hormonal IUDs is a little different from the other birth control methods we've talked about so far. Research has shown that this birth control isn't likely to cause an increase in weight gain. However, one study found that women with a hormonal IUD had increased body fat compared to women using copper IUDs. Other studies have found different results, though.
Myth vs. fact: The shot causes weight gain
Multiple (but not all) birth control studies have found that women on the shot have gained more weight than women using other birth control methods. This study, published in the reproductive health journal, Contraception, in 2014, found that women using the shot gained more weight and body fat over time than those with a copper IUD.
Birth control that won't affect weight
Aside from the copper IUD, there are other ways to prevent pregnancy that don't use hormones and, therefore, won't affect your weight. These include (with their failure rates):
Male condoms: With typical use, condoms have a failure rate of 13 out of 100.
Diaphragms and cervical caps: With typical use, diaphragms and cervical caps have a failure rate of 13 out of 100.
Sponges: With typical use, sponges have a failure rate of 14 to 37 out of 100 (the higher number is for women who have given birth before.
Spermicides: With typical use, condoms have a failure rate of 21 out of 100.
**For comparison, the pill has a failure rate of 7% with typical use.
Weight gain is a common concern with women who are thinking of trying birth control, as well as women who are already on it.
Most studies agree that birth control shouldn't make you gain weight. Still, that doesn't mean that different hormonal birth controls won't cause weight gain in some individuals. Plus, others may experience water retention that feels like weight gain.
Before you decide on a birth control, talk to your doctor about your options. There's a lot out there these days. If one method isn't working for you, you can always try something else. Your doctor should work with you to find a birth control that fits your lifestyle without any unwanted side effects.
Gallo M et al. Combination contraceptives: effects on weight. Cochrane Library. Published January, 2014.
Lopez L et al. Progestin‐only contraceptives: effects on weight. Cochrane Library. Published August 28, 2016.
Institute for Quality and Efficiency in Health Care. Contraception: Do hormonal contraceptives cause weight gain? Updated June 29, 2017.
Mayo Clinic. Combination Birth Control Pills. Published January 9, 2019.
Maholtra R et al. Young adult weight trajectories through midlife by body mass category. Published February 2013.
American Academy of Family Physicians. Side Effects of Hormonal Contraceptives. Published December 2010.
Liao P. Half a century of the oral contraceptive pill. Canada Family Physician. Published December 2012.
Reubinoff B et al. Effects of low-dose estrogen oral contraceptives on weight, body composition, and fat distribution in young women. Fertility and Sterility. Published March 1995.
Milsom I. Effects on cycle control and bodyweight of the combined contraceptive ring, NuvaRing, versus an oral contraceptive... Human Reproduction. Published June 8, 2006.
Mayo Clinic. Birth Control Patch. Published January 26, 2019.
Santos, P et al. Changes in body composition in women using long-acting reversible contraception. Contraception. Published April 2017.
Dal'Ava, N et al. Body weight and composition in users of levonorgestrel releasing intrauterine system. Contraception. Published March 23, 2012.
Gallo, M et al. Association of Progestin Contraceptive Implant and Weight Gain. Obstetrics & Gynecology. Published March, 2016.
Taneepanichskul S., Reinprayoon, & Jaisamrarn. Effects of DMPA on weight and blood pressure in long-term acceptors. Contraception. Published May 1999.
Dal'Ava et al. Body weight and body vomposition of depot medroxyprogesterone acetate users. Contraception. Published August 2014.
CDC. Birth Control Methods. Reviewed August 13, 2020.