What Is the Best Birth Control to Not Gain Weight?

Most forms of birth control do not cause clinically meaningful weight gain, and the methods least associated with any change are the copper IUD and the hormonal (levonorgestrel) IUD. A large Cochrane review of 49 trials found no evidence supporting a causal link between combination oral contraceptives and weight change, and most head-to-head comparisons between different pills showed no substantial difference. The one clear outlier is the injectable progestin shot (Depo-Provera), which consistently shows more weight gain than other methods across multiple studies. Beyond that, the picture is more nuanced than “hormonal equals weight gain,” and the type of hormone, its dose, and the way it is delivered all matter more than whether a method is hormonal at all.

What the Largest Reviews Say About the Pill

The idea that birth control pills make you gain weight is one of the most persistent beliefs in reproductive health, and the evidence does not support it for most people. A Cochrane systematic review that pooled data from 49 randomized trials, covering 85 weight-change comparisons across 52 distinct contraceptive pairs, concluded that available evidence was “insufficient to determine the effect of combination contraceptives on weight, but no large effect was evident.” The four placebo-controlled trials in the review found no causal association between combination oral contraceptives (or a combination skin patch) and weight change. Equally telling, discontinuation rates due to weight change did not differ between groups in the studies that tracked this.¹

A separate study that specifically looked at body composition, not just scale weight, reinforced this. Among 150 women who used oral contraceptives for three to four months, there were no clinically or statistically significant changes in weight or body composition, whether the women were normal weight or obese at baseline.² That matters because it addresses a common worry: that the pill might redistribute fat or increase body fat percentage even if the number on the scale stays the same. In this study, it did neither.

The Depo-Provera Shot Is the Outlier

If there is one contraceptive method that reliably shows up in study after study as linked to weight gain, it is depot medroxyprogesterone acetate, commonly known as the Depo-Provera shot. This injectable progestin is given once every three months, and its association with weight gain is not a myth. In a study of Navajo women, those on DMPA gained an average of about 6 pounds over one year and 11 pounds over two years compared to a control group, even after adjusting for age and initial weight.³ Another study from Ethiopia documented weight gain of 1 to 14 kg among DMPA users, with about 18% experiencing gains of 10% or more of their baseline body weight.⁴

The most informative data comes from a large randomized trial that directly compared DMPA to a levonorgestrel implant and a copper IUD. At the end of follow-up, the DMPA group gained an average of 3.5 kg, the implant group gained 2.4 kg, and the copper IUD group gained 1.5 kg. Expressed as percentages, those were 5.5%, 3.7%, and 2.5% increases respectively. DMPA users gained about 2 kg more than copper IUD users, a statistically significant difference.⁵ A Cochrane review of progestin-only contraceptives confirmed this pattern, noting that weight gain with DMPA was greater than with the copper IUD at one, two, and three years of use.⁶

What makes the shot different from other progestin methods is the dose and delivery. DMPA delivers a high bolus of progestin that circulates systemically at levels much higher than what a hormonal IUD releases locally. The mechanism behind the weight gain is not fully pinned down, but increased appetite and changes in fat storage are both suspected contributors.

How IUDs Compare

The copper IUD contains no hormones at all, which makes it a useful benchmark. Any weight change in copper IUD users over time reflects normal background fluctuation, life changes, and aging, not a drug effect. It consistently serves as the “control group” in contraceptive weight studies, and the average gain in those users tends to hover around 1 to 1.5 kg over a year or more.

The hormonal IUD, which releases levonorgestrel directly into the uterus, performs remarkably well by comparison. A study that tracked users of four different progestin-only methods found that levonorgestrel IUD users gained an average of about 1 kg at 12 months, essentially the same as copper IUD users. After adjusting for age and race, neither the hormonal IUD nor the etonogestrel implant showed a statistically significant weight difference compared to the copper IUD.⁷ A five-year study found the same thing: the levonorgestrel IUD caused no significant weight increase, and the difference was of the same magnitude as that seen in copper IUD users.⁸

For anyone whose top priority is avoiding weight gain, either type of IUD is a strong choice. The hormonal IUD has the added benefits of lighter periods and in many cases fewer cramps, while the copper IUD avoids hormones entirely. Both are highly effective at preventing pregnancy, and neither moves the scale in a way that differs from what happens without contraception.

What About Implants and Progestin-Only Pills

The etonogestrel implant (sold as Nexplanon) sits in a gray area. Short-term data is reassuring: a trial that compared women getting the implant to a control group found no significant difference in weight at one or three months. Perceived weight gain was more common in the implant group at three months, even though measured weight gain was not.⁹ That gap between what people feel is happening and what the scale shows is a recurring theme in contraceptive research.

Longer-term implant data is messier. An exploratory study of genetic factors found a median weight change of +3.2 kg among implant users, though the range was enormous, from losing 27.6 kg to gaining 26.5 kg. The researchers also found that a specific estrogen receptor gene variant was associated with dramatically more weight gain, suggesting genetics may explain why some implant users gain substantially while most do not.¹⁰ The practical takeaway is that the implant probably does not cause meaningful weight gain for most users, but a subset of women may be genetically predisposed to gain more.

For progestin-only pills (the minipill), the evidence is thin but mostly reassuring. Across 22 studies, mean weight gain at six or twelve months was less than 2 kg for most, and study groups generally did not differ significantly from controls. Multi-year data showed roughly double that amount at two to four years, but again with no clear difference from non-users.⁶

Drospirenone and the Fluid Retention Factor

Some of what people experience as “weight gain” on hormonal contraceptives is actually fluid retention caused by estrogen. Estrogen activates aldosterone receptors in the kidneys, which tells the body to hold onto sodium and water. Most progestins do nothing to counteract this. Drospirenone is different: it has anti-mineralocorticoid activity, which means it blocks the aldosterone effect and helps the body shed excess fluid.

Clinical studies have shown that pills containing drospirenone (such as those marketed under brand names like Yasmin and Yaz) had a more favorable effect on body weight compared to pills with other progestins like desogestrel. Women taking the drospirenone-containing pill tended to maintain body weight below their baseline for the majority of the study period, while those on the comparison pill did not.¹¹ This does not mean drospirenone causes fat loss. It means it prevents the water weight that estrogen-containing pills can cause. If bloating and fluid-related weight changes are your main concern, a drospirenone-containing pill is worth discussing with your provider.

Why People Think They Gained Weight When They Did Not

A strange finding shows up repeatedly: women on contraceptives report gaining weight at much higher rates than their actual measured weight change would justify. In the implant study mentioned earlier, about 15% of implant users reported perceived weight gain at three months, but measured weight gain did not differ from the control group.⁹ A study of etonogestrel implant users found minimal agreement between subjective reports of weight gain and actual measured changes, with a Cohen’s kappa of just 0.21, barely better than chance.¹⁰

This perception gap has real consequences. Perceived side effects, including weight gain that may not actually be occurring, drive high rates of contraceptive discontinuation.¹² Stopping birth control for a side effect that is not really happening puts people at risk of unintended pregnancy. If you feel like you are gaining weight on a new method, stepping on a scale at the start and periodically afterwards gives you real data instead of guesswork.

There is one biological angle worth knowing about, though. Early research suggests that combined oral contraceptives may increase the risk of binge eating and cravings for sweets in genetically susceptible women, which could lead to real caloric surplus and genuine weight gain in a roundabout way.¹³ The research on this is still early, but it offers one possible explanation for why a minority of pill users do gain weight even though placebo-controlled trials show no average effect.

Teenagers and the Depo-Provera Problem

Adolescents deserve a separate mention because their bodies are still changing, and the DMPA shot appears to hit them harder than adults. In one study, 25% of teen DMPA users gained more than 10% of their baseline weight within a year, compared to just 7% of teen oral contraceptive users.¹⁴ A useful early warning sign emerged: teens who gained more than 5% of their body weight by three months almost universally continued gaining through the rest of the year.

The risk is amplified for teens who are already obese. A study comparing obese and non-obese adolescent girls found that obese girls starting DMPA gained an average of 9.4 kg at 18 months, compared to just 0.2 kg for obese girls on oral contraceptives and 3.1 kg for obese girls using no hormonal method at all. There was also a significant interaction between length of time on DMPA and weight gain for obese subjects, meaning the longer they stayed on it, the more the weight accumulated.¹⁵ For teens and their parents weighing contraceptive options, these findings strongly favor an IUD, implant, or pill over the injection if weight is a concern.

Considerations for People With Higher Body Weight

If you already carry extra weight, there are two separate questions: will contraception make it worse, and will your weight affect how well the contraception works?

On the first question, the evidence supports combined oral contraceptive use in carefully screened obese women who don’t have known cardiovascular risk factors. IUDs are particularly well-suited because their efficacy is not reduced by body weight, though insertion may sometimes be more difficult.¹⁶

On the second question, the answer matters most for emergency contraception. Levonorgestrel-based emergency contraceptive pills (like Plan B) show significantly reduced effectiveness in women with higher body weight. A pharmacokinetic study found that blood levels of levonorgestrel were about 50% lower in obese women compared to normal-weight women, likely explaining the reduced efficacy.¹⁷ One analysis found that estimated pregnancy rates with levonorgestrel emergency contraception rose from about 1.4% in women weighing 65-75 kg to over 6% in women weighing 75-85 kg.¹⁸ Ulipristal acetate (sold as Ella) showed much more stable blood levels across weight groups in the pharmacokinetic study, making it a better emergency option for women with higher BMI. The copper IUD, which can also be used as emergency contraception and is the most effective option regardless of weight, is worth considering if you are in that situation.

PCOS and Oral Contraceptives

Women with polycystic ovary syndrome are often prescribed oral contraceptives to manage symptoms like irregular periods and acne, but the metabolic picture is more complicated. A study comparing women with and without PCOS found that after three months on a combined oral contraceptive, glucose tolerance worsened in the PCOS group compared to controls, and beta-cell function (the ability to produce insulin in response to sugar) declined significantly.¹⁹ These metabolic shifts don’t directly translate to weight gain, but worsened insulin resistance can make weight management harder over time, particularly for women with PCOS who already tend to struggle with it. If you have PCOS and are concerned about both symptom management and weight, these trade-offs are worth an honest conversation with your provider.

Exercise and Lifestyle Still Matter

Even for the methods most associated with weight gain, lifestyle habits appear to make a genuine difference. A study of three-month injectable contraceptive users found that reducing sedentary behavior and increasing physical activity could prevent the rise in BMI that is otherwise common with this method.²⁰ That finding is not surprising, but it is worth stating plainly: choosing a method that is associated with modest weight gain does not doom you to gaining weight. If you are on the shot and notice the scale creeping up early, you have a window to intervene with changes to your activity level, and the data from adolescents suggests that early weight gain predicts continued gain if nothing changes. Paying attention to that three-month mark gives you actionable information rather than letting a trend build up unchecked over a year or two.

1
Cochrane Database of Systematic Reviews. Combination contraceptives: effects on weight
2
PubMed Central. Weight and Body Composition Changes During Oral Contraceptive Use in Obese and Normal Weight Women
3
PubMed. Depo-provera associated with weight gain in Navajo women
4
PubMed Central. Changes in body weight and blood pressure among women using Depo-Provera injection in Northwest Ethiopia
5
EClinicalMedicine. Weight change among women using intramuscular depot medroxyprogesterone acetate, a copper intrauterine device, or a levonorgestrel implant for contraception
6
PubMed Central. Progestin‐only contraceptives: effects on weight
7
PubMed Central. Weight Change at 12 Months in Users of Three Progestin-Only Contraceptive Methods
8
Revista da Associação Médica Brasileira. Weight variation in users of the levonorgestrel-releasing intrauterine system, of the copper IUD and of medroxyprogesterone acetate in Brazil
9
PubMed Central. Association of Progestin Contraceptive Implant and Weight Gain
10
PubMed Central. An Exploratory Analysis on the Influence of Genetic Variants on Weight Gain among Etonogestrel Contraceptive Implant Users
11
PubMed. Added benefits of drospirenone for compliance
12
Journal of the Endocrine Society. SAT-115 Oral Contraceptive Discontinuation Due To Perceived Weight Gain In Women With And Without Polycystic Ovary Syndrome
13
PubMed Central. Combined oral contraceptive use and risk for binge eating in women: Potential gene × hormone interactions
14
PubMed. Weight change in adolescents who used hormonal contraception
15
JAMA Pediatrics. Weight Gain in Obese and Nonobese Adolescent Girls Initiating Depot Medroxyprogesterone, Oral Contraceptive Pills, or No Hormonal Contraceptive Method
16
PubMed Central. Contraception and the obese woman
17
PubMed. Pharmacokinetics of levonorgestrel and ulipristal acetate emergency contraception in women with normal and obese body mass index
18
PubMed. Effect of body weight and BMI on the efficacy of levonorgestrel emergency contraception
19
PubMed Central. Metabolic Effects of a Commonly Used Combined Hormonal Oral Contraceptive in Women With and Without Polycystic Ovary Syndrome
20
Jurnal Berkala Epidemiologi. The Influence of Lifestyle on BMI Change for Tree-Month Injectable Hormonal Contraceptive Users