Birth control & weight gain - myths & facts | Pill, implant, & IUD

Birth control use is very common in the United States. According to the CDC, 65% of women use some form of contraception with about 42% of those women using a pill, implant, or IUD. While a very effective means of preventing pregnancy, many women are hesitant to start birth control or they discontinue use due to concerns about weight gain. But is weight gain from birth control a myth or fact? Are some forms of birth control a better option than others? This article will take a look at the research on this topic and provide strategies for addressing this potential side effect.

Does birth control cause weight gain? 

While this is a commonly held belief among healthcare professionals and women of child-bearing age, the research doesn’t exactly back it up for most women. As with most medications, there are a wide range of biological responses. A medication can work extremely well for one person but have almost no effect for another person. We see something similar happen with side effects. Not only can we not predict who will develop side effects, but from the same medication it is possible one person gains a lot of weight, another sees no change, and yet another might even lose weight. Let’s look more specifically at the different forms of birth control and how they affect weight, while keeping in mind that an individual weight gain response is always possible, even if the research shows that on average, most people don’t. 

Do IUDs cause weight gain?

There are two types of intrauterine devices (IUDs) used for contraception - a progesterone-containing (hormonal) IUD and a copper (non-hormonal) IUD. Copper IUDs have not been found to cause weight gain. 

With hormonal IUDs, there are reports of women who experience weight gain as a side effect and even discontinue use for this reason. However, the research on IUDs and weight gain suggests that this is a rare side effect and the amount of weight gain experienced is not significantly different from placebo. Data from the manufacturers of Liletta^Ⓡ  and Mirena^Ⓡ, two hormonal IUDs on the market, suggest that 6% of women experienced weight gain after more than 1 year of use. Additionally, the average weight change appears to be small with one study showing an average weight gain of just 1 pound after 1 year of use and another showing about 6 pounds gained after 1 year of use compared to 3 pounds on placebo. 

Do contraceptive implants cause weight gain?

The contraceptive implant, also known by brand name Nexplanon^Ⓡ, has been associated with weight gain in multiple studies. According to the manufacturer, clinical trials showed that about 14% of women in the study gained 2-4 pounds on average after 1-2 years of use. Another study suggests this number could be as high as 7 pounds on average, and we have to keep in mind that averages don’t tell the full picture and some women will have gained significantly more than the average, while others less. Research shows as many as 20% of women with the implant report discontinuing use of contraceptive implants due to weight gain.

Do combined contraceptives cause weight gain (the pill, the patch, or the ring)?

Combined contraceptives are birth control methods that contain two hormones - estrogen and progesterone. These hormones can be delivered in the form of a pill, a skin patch, or a vaginal ring, depending on patient preference. A comprehensive review looking at multiple studies of combination contraceptives concluded that these birth control methods do not cause significant weight gain on average. With that said, as this is the average, it may not be the case for all women. Reviewing the prescribing information for a number of these products, it appears that small percentages of women (about 3-5%) do report experiencing weight gain during the clinical trials. 

Does the Depo-Provera® shot cause weight gain?

The Depo-Provera (medroxyprogesterone acetate) injection is the one birth control method that has been consistently linked to significant weight gain. Prescribing information from the manufacturer indicates that 38% of women gained more than 10 pounds after 2 years on the injection in clinical trials evaluating the safety of the drug. Another study showed similar findings, with an average weight gain of about 8 pounds after 2 years on the injection and 11 pounds after 3 years on the injection. This study also found that women gained more weight in the midsection with use of Depo injections, which increases the risk for conditions such as type 2 diabetes and cardiovascular disease.

The bottom line is that most forms of birth control do have at least a slight risk of weight gain, but based on the research, the majority of women will not experience this side effect. Combined contraceptives and IUDs appear to be the least likely to cause weight gain, but may not be appropriate for all women. You should have a thorough discussion with your healthcare provider about which option is best for you and monitor for changes in your weight after initiation. 

Why does weight gain from birth control happen?

The research regarding why some women gain weight from birth control is largely inconclusive. Some potential reasons that have been considered by scientists include water retention, increased appetite from estrogen, and/or increasing blood sugar levels from progesterone. It’s important to note, however, that none of these theories have been confirmed to be the cause of weight gain from birth control. 

What can you do about weight gain from birth control?

If you’ve experienced weight gain from birth control, there are some things you can do: 

1. Give it time. If the water retention theory is true, then your weight will stabilize again once your body has adjusted to the increased estrogen in your system. Just be sure to step on the scale regularly so you’re aware of what is happening with your weight and can address continued weight gain sooner rather than later. 
   

2. Follow a calorie-restricted diet. Reducing your calorie intake has been shown time and time again to be effective for weight loss. But extremely restrictive diets don’t typically work for long, so aim to do this in a way that feels sustainable. Typically, reducing portion sizes and eating more healthful, lower-calorie foods such as fruits, vegetables, and lean protein will help you to achieve weight loss. Additionally, tracking your food intake with an app can help you to be more aware of how much you’re eating. A Registered Dietitian is a great resource for providing you with guidance on an appropriate diet for weight loss if you’re having difficulty doing it on your own. 
   

3. Increase your physical activity level. Moving more burns more calories and helps to create the calorie deficit you need to lose weight. Going to the gym for an aerobics class or using a home workout video are great ways to increase your physical activity level, but also consider all of the non-exercise movements you’re doing. Parking farther away, walking your dog a bit longer, and playing with your kids are ways to easily incorporate more physical activity into your day if you are struggling to find time for dedicated exercise. It all adds up to burn more calories! 
   

4. Discuss alternative birth control methods with your healthcare provider. Just because you experienced changes in your weight with one method doesn’t mean you will have the same response to a different method. As discussed above, some birth control options are more likely to result in weight gain than others and there is a lot of individual variation, so there may be other good options for you to consider that will not adversely affect your weight. 
   

How Form Health can help you with weight gain from birth control

Form Health recognizes that many medications play a role in weight gain, with various birth controls being some of them. The Obesity Medicine Physicians at Form use evidence based methods to create personalized programs based on any medical history or medication use. Any medication or birth control will be assessed during the initial process to see if it may be contributing to any weight gain. 

Our Board Certified Doctors and Registered Dietitians will work with you to build healthy habits and a weight loss plan that consists of behavioral support, nutrition, physical activity, and if appropriate, FDA approved medicine. The tele-health program is done entirely though the Form Health app, where patients have unlimited, frequent access to communication and messages with their paired Doctor and Registered Dietitian. Find out if you are eligible by taking our quiz now. 

Depo-Provera^Ⓡ is a registered trademark of Pfizer Inc. 

Liletta^Ⓡ is a registered trademark of Odyssea Pharma SPRL.

Mirena^Ⓡ is a registered trademark of Bayer. 

Nexplanon® is a registered trademark of Organon.