Does birth control make you gain weight? What the research (and real life) says

When it comes to birth control pills and other contraceptive options, it can be hard to separate fact from fiction. An option that may work wonders for one person can cause any number of side effects for another, and finding the right option for you can be a daunting process.

One side effect many people worry about is weight gain that comes as a result of taking hormonal birth control. But when it comes to weight gain and birth control pills, what does the science actually say?

In this article, we'll break down everything you need to know about birth control and weight, and what you can do to prevent pregnancy without gaining weight in the process.

Can birth control cause weight gain?

When it comes to birth control pills, it's one of the most common concerns that people have. "Does birth control make you gain weight?" — maybe you've even asked your doctor before.

But the short answer is, "It depends".

While some people report weight changes and weight gain, there isn't a ton of strong evidence to link hormonal contraception to significant weight gain. In fact, despite significant research in the area, there's very little scientific proof that birth control pills can make you gain weight [1].

But with that being said, it's not uncommon to notice fluctuations in your weight after starting birth control pills, most commonly in the first few months as your body adjusts to the medication. Several factors can cause weight gain from various birth control methods, the most notable of which are fluid retention [1], changes in appetite, and other lifestyle factors that aren't connected to your birth control.

Why might birth control lead to weight gain in some people?

So, if birth control doesn't cause weight gain, why do so many people say that it does? Great question.

While birth control pills aren't proven to cause weight gain, they can affect the body in ways that indirectly contribute to weight gain for some people.

Any hormonal birth control method — like the pill, the shot, or a hormonal IUD — contains a synthetic form of estrogen and/or progestin, and these hormones can do a number on your body, increasing your appetite, causing fluid retention, or even subtly changing how your body stores fat [1][2].

Some studies suggest a slight increase in body fat or lean body mass depending on the method used, but these changes vary from person to person [3]. Other factors — like stress, sleep, diet, and the body’s unique response to hormones — also play a role [4].

Can the pill change your body shape?

Another common idea is that birth control pills can change your body shape. However, the research on whether this is the case or not remains inconclusive.

Currently, there’s no consistent evidence to show that combination pills or progestin-only pills (also called the mini pill [4][5]) can cause a visible change to your body shape. With that being said, there is some evidence that supports the claim.

One study showed that women on birth control pills with higher levels of oestrogen had higher levels of subcutaneous fat cells, which gave them more of a pear-shaped figure [6].

Still, for the most part, the idea that birth control pills change the shape of your body can be attributed to water retention, particularly around the hips, breasts and thighs [7]. This is because oestrogen impacts the way your body metabolises water. And in turn, this can make it feel like your body shape has changed.

That being said, this increased level of water retention is usually mild and temporary, so things should settle down after a few months

Types of birth control and how they can affect your weight

Different birth control methods affect people in different ways, so the impact they can have on your body — and your weight as a result of that — can vary greatly from person to person.

Hormonal birth control options, like the combined pill, the mini-pill (or progestin-only pill), hormonal IUDs, the patch, the ring, or the contraceptive injection, can cause mild fluid retention and/or appetite changes.

Of these options, the contraceptive injection is the most commonly associated with potential weight gain, with one study showing an average weight gain of 2.4kg over four and a half years [8]. On the other hand, non-hormonal options like the copper IUD don’t contain hormones and have not been linked to weight changes [9].

Is it harder to lose weight on birth control?

While it's possibly harder to lose weight while on birth control, it's certainly not impossible, particularly if you find the right birth control method for you.

Some people do find that it's harder to lose weight while taking birth control pills, likely due to the water retention, increased appetite, and mood changes that hormonal birth control methods can cause, as well as the subtle metabolic changes.

However, many women find that they're able to maintain or even lose weight while on birth control. One study found that in some birth control groups, participants actually experienced no significant weight gain or even saw slight reductions in weight over time [10].

Still, while there's no direct correlation between most birth control methods and a long-term weight loss plateau, if you've noticed changes that concern you, your best bet will always be to speak to your doctor about it.

How to reduce the risk of weight gain on birth control

If you're about to start taking birth control and are worried about potential side effects and weight gain, there are a few things you can do to reduce the likelihood of significant weight gain.

Essentially, it comes down to the basics — eating a balanced diet with plenty of lean protein, staying hydrated, and getting regular, quality sleep. And of course, it's important to stay active with regular movement — even a gentle walk can help your body adjust more smoothly, supporting your hormonal balance and reducing fluid retention.

If you're starting birth control, it's a good idea to jot any symptoms or possible side effects down as you notice them. That way, you can spot patterns early on, and if you're struggling or find that they persist over time, speak to your doctor, as there may be a better option out there for you.

How to manage unexpected weight gain

If you've recently started taking birth control and noticed yourself gaining weight unexpectedly, you're certainly not alone, and of course, it's nothing to be ashamed of. But if you're finding yourself distressed by the weight gain, don't panic — there are ways to manage it.

For some people, the weight gain may just be temporary water retention, while for others, it could be that the hormonal shifts have led to an increased appetite, or emotional eating brought on by changes in mood. Or, it could be linked to other factors, like stress or other lifestyle changes.

If you're doing all the usual things, like eating a healthy, balanced diet, drinking enough water, exercising regularly and getting enough sleep, then there may be factors beyond your control at play. In this instance, you should chat to your doctor about the weight gain and consider whether there may be a different birth control method that works better for you.

How to lose weight on birth control (safely)

If you've noticed weight gain after starting birth control, don't fret — it's still possible to lose weight while taking birth control. But if you've found that the usual methods aren't working for you, then Juniper's Weight Reset Program may be exactly what you're looking for.

Whether your birth control is having an impact on your body weight or whether it's other lifestyle factors, Juniper's Weight Reset Program is a holistic approach to long-term, sustainable weight loss that pairs medical weight loss treatments with dietitian-led health coaching and a private community of like-minded people who are all on the same journey as you.

At Juniper, we don't just want to help you lose weight; we want to set you up for success with the tools you need to address any lifestyle factors that are leading to weight gain. And, we're proud to report that it works: Juniper patients are 4.5x more likely to lose significant weight than people who are trying to lose weight with treatment alone.

Interested? Check your eligibility today.

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