Does birth control cause weight gain? It’s a common side effect women report, yet it is often dismissed because the research is largely inconclusive. Concerns about weight gain are one of the highest reported barriers to women choosing to begin birth control and one of the number one reasons women quit it.
Wait, if weight gain is a top reason women stop birth control then isn’t there some truth to this idea that birth control can lead to weight gain? Yes, there are ways in which birth control can lead to weight gain and we’re going to explore them in this article.
Odds are you’ve experienced this or at least know someone who has. And I’d venture to guess you’ve probably heard it is a myth. The truth is, we don’t have a lot of great studies available and many of the ones we do have are flawed.
How Birth Control Can Contribute to Weight Gain:
- Fluid retention
- Low testosterone
- Loss of muscle mass
- Estrogen dominance
- Progestin replacing progesterone
- Low thyroid hormone
The issue is studies report average weight gain, which includes both women who have lost and gained weight. In some studies we’ve seen pretty extreme weight gain and weight loss, but once you calculate the average, it seems pretty negligible. That is, unless you’re the women who gained over 50 lbs!
In one study it was found that the depo provera shot resulted in increased weight and body fat, while the pill did not. It's confusing and enough to drive a gal crazy. But at the end of the day, what is most important is what is true for you.
Oh and just so we are super clear—this article isn’t body shaming, promoting thin as the only metric of wellness or health, and certainly isn’t saying you should go out and try to change your body. Instead, I’m answering a very common reader question and trying to provide clarity on this topic. Also, you 100% have the right to be concerned about your weight gain, body composition and shouldn’t feel shamed into “body positivity” because you question it. That is some toxic positivity BS that is just as damaging as diet culture. And yes, your weight changes can be a sign of big trouble in your body, which is why if you're concerned then my doctor brain is also concerned. Whew! Now let's keep moving!
Birth Control Related Weight Gain Disclosed on Package Insert
I think it is important to know that while the question of weight gain is often dismissed, it is listed as a side effect on the package insert of birth control pills and hormonal IUDs. That’s right, the manufacturers of these pharmaceuticals list it, but countless people, including doctors, line up to dismiss it. To be fair, it is considered rare, but just because something is “rare” doesn’t mean you don’t deserve to be in the know.
Is birth control weight gain temporary?
Here’s the deal, there are several studies that suggest the weight gain caused by the pill and other forms of hormonal contraceptives is a result of water retention. And this is true, for some women. If you’re a gal who started birth control, gained weight and then stopped and lost it immediately then yes, that is probably a water retention issue. And in this instance, yes, the birth control weight gain is temporary.
But there is so much more to the story!
There are studies that have shown the pill can lead to lower muscle mass and strength gains—and, by extension, a slower metabolism. The fastest way to bump your metabolism is to build muscle, but birth control can definitely mess with those #gymgoals.
This is the kind of body composition change that doesn't just resolve when you stop birth control.
As with any symptom, it’s important to look at the bigger picture. So instead of focusing solely on weight gain, we need to understand how and why the pill could be impeding your health and fitness goals.
To do this, I’m going to start by explaining the effect of the pill on one particular hormone: testosterone.
Can Birth Control Impair Muscle Gains?
They definitely can! As I explain in Beyond the Pill, hormonal birth control lowers testosterone production and also increases sex hormone binding globulin (SHBG), which grabs onto any testosterone you do make.
Yes, ladies, you need testosterone too! It’s an important hormone for women, and affects our brain and bone health, increases energy, and helps with weight loss. Testosterone that is too high or too low leads to unpleasant symptoms like hair loss, loss of libido, depression, and acne, so we really want this hormone to be optimized.
Many teens and women struggling with acne are prescribed the pill to clear their skin by lowering testosterone in the body. In addition, certain progestins (synthetic progesterone) also bind androgen receptors and do not allow for the anabolic (muscle building) effects that testosterone and DHEA can offer.
How Birth Control Pills Affect Testosterone
The pill decreases testosterone production by up to 50 percent, and also leads to increased sex-hormone-binding globulin (SHBG). SHBG binds free testosterone—meaning that it is no longer available for use by the body. The result is that women on the pill produce much less testosterone, and SHBG binds the free testosterone in the body. The bound hormone cannot be used by your cell’s receptors.
Some birth control pills also block androgen (e.g. testosterone and DHEA) receptors, which helps to reduce acne. And while that’s great, it also means that those androgens can’t facilitate muscle growth—which will make your gym goals and impact your performance. Not to mention the long-term effects on your metabolism and libido. #lame
Women need testosterone. Not too much, but with it we are smarter, faster, stronger…I kinda feel a Kayne song coming on.
Testosterone and your metabolism in a natural menstrual cycle
In Beyond the Pill, I school you in ways you sex ed teacher should have, but didn’t, about the menstrual cycle and the different hormones involved. Testosterone is one of them. And girl, when testosterone is right, it is so good!
During the follicular phase of your cycle, testosterone rises leading up to ovulation It’s all designed to make you want to engage in sex to boost the chances you’ll get pregnant. Psst…don’t worry, if baby making isn’t on your agenda then you can still leverage the wonderful benefits of testosterone.
Research shows that our peak performance is up during the follicular phase, so it’s an opportune time to make progress in muscle mass and strength—time to lift some weights!
BTW, if you’ve been told you’ll “get bulky” then you can forget all of that business because it is some kinda weird story that gets told without being grounded in facts.
Additionally, if you are having a natural menstrual cycle, your metabolism will speed up (causing you to burn more calories) after ovulation in what is called the luteal phase. That’s right! Your Basal Metabolic Rate (BMR) or the amount of calories you burn just as a part of being a human is higher after you ovulate! Another reason why ovulation is so valuable.
On the pill, however, you do not ovulate, so you will not experience these bonus bumps in your metabolism. The worst.
In the “Metabolic Mayhem” chapter of Beyond the Pill, I provide in-depth information on how hormonal birth control affects our metabolism, weight gain, and insulin resistance and may even put us at risk for diabetes.
Does the Pill Affect Athletic Performance?
Over the years, you might have heard recommendations that athletes begin or remain on the pill to overcome the decrease in exercise tolerance during the luteal phase. And while some studies have shown a decrease in time to exhaustion during the luteal phase, other studies have noted that in temperate climates, there is no decrease in female athletic performance during the luteal phase.
In fact, a 2003 study published in the Medicine & Science in Sports & Exercise concluded that “regularly menstruating female athletes, competing in strength-specific sports and intense anaerobic/aerobic sports, do not need to adjust for menstrual cycle phase to maximize performance.”
All this biology can get complicated, so the point I want you to walk away with is this: You don't need to suppress your cycle with the pill to excel as an athlete.
Estrogen Dominance and Weight Gain
We know that excess of natural estrogen can lead to increased adiposity. It is plausible that synthetic estrogen (like you find in birth control) does the same.
In fact, some studies have concluded that the synthetic estrogen found in birth control can be up to ten times as potent as your natural estrogen. Your fat cells are primed with receptors for estrogen, which they readily respond to.
Estrogen is is also made from fat tissue, so the more fat cells you have, the more estrogen you can make.
While the pill does well at shutting down your ovarian function and estrogen production, it doesn’t stop your fat cells from making more fat.
In addition, your natural progesterone is a diuretic, which helps with fluid retention. When estrogen in unopposed by progesterone in a natural cycle it can lead to fluid retention, bloating and increased weight the week leading up to your period. When you're using hormonal birth control your cells are being exposed to progestin, which is in no way as beneficial as your natural progesterone and does not help you keep from retaining water. This is one reason why some women may gain weight on birth control—fluid retention.
Thyroid Making You Gain Weight?
It is well recognized that low thyroid can present with weight gain. Yup, when that thyroid hormone goes low then your weight climbs.
And I hate to be the one to break it to you, but birth control does your thyroid no favors. Read the Thyroid Birth Control Connection and get in the know on this little known side effect. And if you need a deeper dive, Beyond the Pill has got you covered.
There are several ways in which birth control can impact thyroid health, with a big one being increasing thyroid binding globulin. This is a protein that binds to your thyroid and doesn’t allow your cell’s to use it. The result? You have hypothyroid symptoms while your TSH (thyroid stimulating hormone) looks “normal.”
How Can I Avoid Gaining Weight on Birth Control
This is a common question amongst my patients who want to start birth control for pregnancy prevention. In some cases, we can support women in maintaining their weight and fitness goals. In others, not so much.
What’s the difference? I’m so glad you asked because this is exactly what we need research to answer. Because we don’t all respond the same to birth control, yet many doctors think we should. 🤷♀️
Some women experience no weight gain. Others lose weight! And then, there are those of us (girl, this was me too) that see the weight creep up despite our best efforts.
How to Boost Your Metabolism Naturally
Whether you are on or off the pill, the Brighten Metabolic Protocol™ can help you improve your metabolic health. Oh snap, you mean it isn’t just about that number on the scale? Or the size of my clothes? Or the BMI my doc always talks about?
No. Your metabolic health is so much more than just body composition. It covers insulin, liver health, cholesterol, heart health, and so much more! But don’t get overwhelmed. Instead, start these 4 steps of the Brighten Metabolic Protocol!
1. Eliminate sugar and refined carbs.
The pill can cause insulin resistance, blood sugar dysregulation, and possibly a slower metabolism, so it’s important to carefully moderate certain foods like processed carbohydrates, desserts, and white bread.
Look, I’m not a “bad food” person. Food is information for your body. It is also a powerful tool to heal.
Cutting out the sugar is not as awful as it sounds—you can certainly indulge in the occasional piece of cake, donut, or cocktail and nobody round here will be judging you. But you do have to consume way less of the foods that spike blood sugar than the average US resident if you want to get your hormone game on point.
Giving them up completely for at least 3-4 weeks to support your metabolism is a good idea to hit that reset button. When you reintroduce you’ll have a better sense of what works for you.
2. Focus on real, whole foods.
Basically, you want to crowd out the less nutrient dense foods and opt for those that are loaded with the info your body needs to know the environment it lives in is safe and abundant.
The simplest way to do this is to fill your plate with nutrient-dense yumminess: protein, fat, and vegetables at every meal. There will simply be no room for food that doesn’t support your metabolic health. Eating a well-balanced meal also helps your liver and gut detoxify hormones.
Get my Hormone Starter Kit for a seven day nutrient-dense meal plan to help you optimize your hormones in a tasty way.
3. Exercise daily.
It might be frustrating to learn that the pill is messing with your gym gains, but don’t give up! Exercise is good for more than just muscle tone and fat loss. It also results in better moods, lowered inflammation, and increased insulin sensitivity.
Daily movement is what you’re made for. So embrace the animal you are and do what feels good. Sure, there are definitely exercises that you can leverage at each phase of your menstrual cycle, but girl, if you just listen to your body then you’ve got this!
And if you have a part of you that says, “let’s just lay on the couch and eat chocolate” then you know you’re not bad. I’ve got that little voice too. But those endorphins (feel good molecules) that you get from a workout are well worth it. Promise.
4. Find the eating schedule that works for you
If you have hypoglycemic episodes, you may need to eat regular meals to keep your blood sugar balanced. That means for you, eating every 2-3 hours might be part of your healing phase.
When my patients do not struggle with blood sugar crashes, I encourage them to try intermittent fasting. It’s a simple concept: Stop eating at a specific time each night, and do not eat again for 12 (or more) hours.
Intermittent fasting is a popular weight loss tool, and it also helps maintain muscle mass. But the benefits most definitely extend beyond weight loss for longevity, so don’t limit it to the weight loss factor.
It’s not just about calories and exercise
Body composition and maintaining a healthy weight is not just about how much you eat and how much you exercise. Every time I see someone dissing women about their weight because they are a “calories in, calories out” person I feel like they somehow got stuck in 1990's and never caught up with the fact that hormones do play a role.
Please do not fall for the “if you just restrict all the food” or the “if you just spend 3 hours a day in a gym” or the “just ramp up your metabolism with X” that we see on the internet. You're a complex biological organism living in a very artificial environment.
If you’re a man reading this, please refrain from “mansplaining” women’s weight to them based on the research that contained only male subjects. We know you mean well, but man, it doesn’t end well when these words fall on our ears.
Skeptical women’s hormones influence their weight because some doc told you that it wasn’t true? Google hypothyroid symptoms and tell me what you find out about weight gain.
For my women and assigned female at birth crew, your hormones 100% play a role in your metabolism, muscle mass, fat stores, and body composition. Those synthetic hormones in birth control also have an impact.
Your hormones and hormonal birth control play a role in how you build muscle, increase fat tissue, and reach your fitness goals, means that the weight isn’t necessarily all up to you to control with diet and exercise. In fact, I'd encourage you to get lab testing and assess if your body composition is a sign of an underlying issue. You may need to switch or stop birth control based on your symptoms.
In need of more support? Grab my free Hormone Balancing Starter Kit with a 7 day meal plan + recipes to help you get your hormones on track!