Medically reviewed by Dr. Hayley Miller, Medical Director, Weight Management on November 1, 2024
If you’re thinking about starting birth control but you’re worried how it may affect the scale – read on. We’re here to help you better understand the relationship between birth control and weight so you can make an informed decision about your health.
How does birth control affect weight?
Let’s be clear upfront: The majority of birth control options do not directly affect weight. While there is one exception (outlined below), the evidence behind the thought that birth control = weight gain is anecdotal.
So what’s going on, then? First, past versions of the pill had stronger doses of hormones than modern pills do, and reports of weight gain (among other side effects) were much higher with the older pills. It’s possible that these early experiences left a lasting impression.
Still true today, though, is that the hormone estrogen can lead to water retention – AKA bloat – during the first few months of starting your birth control plan. Not permanent, perhaps not even cause a change on the scale, it could be enough to feel like you’re not 100% you for a little while.
Do certain types of birth control affect weight differently?
In today’s day and age, you have many birth control options at your disposal. Let’s review.
The pill
Birth control pills come in a pack. Generally, you take one pill at the same time every day. There are a few variations of the pill, including:
- Combination pills (AKA combined oral contraceptives, or COCs)
- Combination pills have both estrogen and progestin
- These are the most common type of birth control pill
- Progestin-only pills (AKA POPs or mini pills)
- Progestin-only pills only have, well… progestin
The pill, both COC and POP, is not shown to affect weight.
The ring
The birth control ring, commonly known as the brand name, NuvaRing®, is also one of the most common forms of birth control. You insert a small, flexible ring inside your vagina, which releases estrogen and progestin into your body.
The ring is not shown to affect weight.
The patch
You wear the patch on your body much like you would a bandage, and replace it every seven days. A transdermal contraceptive, it releases estrogen and progestin through your skin.
The patch is not shown to affect weight.
Implant
The birth control implant (brand name Nexplanon®) is a tiny, thin rod about the size of a matchstick that’s implanted into your body, typically your upper arm, where it releases progestin. You’ll need to visit a local doctor’s office, where a nurse or doctor will insert it.
It is not connected to weight gain.
IUDs
IUDs (intrauterine devices) are small, T-shaped devices that are placed inside your uterus, where they stay for a long time, usually several years. Hormonal IUDs release progestin. You’ll need to visit a local doctor’s office, where a nurse or doctor will insert it.
Hormonal IUDs are not connected to weight gain.
The non-hormonal, copper IUD is not connected to weight gain.
The shot
The birth control shot (brand name Depo-Provera®) is an injection you get once every three months. It only contains progestin.
Weight gain is a side effect of the shot; approximately less than ten pounds with two years of use.
In a large-scale clinical trial, participants showed an average weight gain of about 4% after one year. By the second year, the average gain was around 6%, and after four years, participants gained about 10% of their body weight.
Others
Emergency contraception, also known as the morning-after pill, also also known as Plan B One-Step®, Opill®, or Ella®, do not cause weight gain. Temporary bloating, though, is among the side effects.
External forms of birth control, such as condoms or diaphragm, do not affect weight because they do not affect hormones.
Can birth control cause weight gain?
Researchers looked at the results of 49 different research studies that analyzed the effects of 52 kinds of combined birth control (pills and patches that contain both estrogen and progestin). The evidence just isn’t there to say that these forms of birth control cause weight gain.
Another study looked at progestin-only birth control pills, hormonal IUDs, and implants. Again, there wasn’t enough evidence to conclude they cause any weight gain.
The only outlier is the shot, which can cause weight gain, as mentioned above.
Can birth control cause weight loss?
There are no birth control methods that actively lead to weight loss. The hormone progestin can act like a natural diuretic, which means it increases your need to pee, resulting in a temporary loss of water weight. This is not the same as losing fat or overall body weight.
How does weight affect birth control and emergency contraception?
Obesity may affect the efficacy of some hormonal contraceptives, but the research is still conflicting. However, there are specific guidelines regarding weight and the effectiveness of certain contraceptives:
- Xulane® may be less effective in preventing pregnancy in women who weigh 198 pounds or more or have a Body Mass Index of 30 or higher. NuvaRing may be a better option for those who weigh more than that.
- Plan B One-Step® is not as effective for people who weigh 164 pounds or more. Ella® is a better option for those who weigh more than that.
Do weight loss medications affect how well my birth control works?
Potentially, yes. GLP-1s* can reduce the effectiveness of oral contraceptives, especially when you first start taking GLP-1s or increase the dose. This is because GLP-1s can slow down stomach emptying. Meanwhile, most birth control pills need to be absorbed at the same time every day to work properly.
Vomiting, a possible side effect of some weight management medications, can also make birth control less effective.
Over time, the way GLP-1 medications* affect stomach emptying usually evens out. It’s best to talk to your birth control provider to find the right options for you. In the meantime, using backup protection when starting a GLP-1 medication is recommended.
What can I do to manage my weight while still taking birth control?
Following a healthy lifestyle is your best bet to managing weight while on (or off!) birth control. Focus on eating a balanced diet with plenty of fruits, veggies, lean proteins, and whole grains. Regular exercise, like walking or strength training, also support weight management.
If, along the way, you’re still concerned, you can talk to a healthcare professional about weight management medications. Want to take the first step, today? Nurx can help you get started here.
The bottom line
Studies show birth control pills are unlikely to cause an uptick on that scale. But at the same time – many users still report perceived weight gain. You don’t want fear or uncertainty around side effects to hold you back from choosing a birth control option that is the best fit for you. Reach out to a Nurx provider for support here.
*Compounded drugs are not FDA-approved or evaluated for safety, efficacy, or quality. Nurx compound drug offerings are not available to patients in California or Hawaii.
Services and treatments, not offered in every state, include medical treatment of overweight and obesity including lifestyle counseling (e.g., diet and exercise) and prescription medications, if clinically appropriate, based on completion of required consultation. Nurx requires regular check-ins to monitor your progress. Weight loss may be associated with other symptoms including but not limited to muscle loss, fatigue, menstrual changes, gallstones, and mood changes. Extreme/rapid weight loss may result in nutritional deficiencies that lead to hair loss, anemia, weak bones, or increased risk of infection. Talk to your provider immediately about symptoms. Many people with overweight or obesity who lose weight have a tendency to regain all or some of the weight over time. Overweight and obesity medication efficacy increases with the addition of diet and exercise. Individual response to treatment may vary and is not guaranteed by Nurx.
The information provided is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon this content for medical advice. If you have any questions or concerns, please talk to a medical professional.