Birth Control and Weight Gain: What the Evidence Says

By Mustafa Bilgic · Updated June 2026 · Reviewed against guidance from ACOG, the Mayo Clinic, MedlinePlus (NIH), and Planned Parenthood.

"Will birth control make me gain weight?" is one of the most common questions about contraception — and the research-backed answer surprises many people. For most hormonal methods, high-quality reviews have not found strong evidence that they cause significant weight gain. The notable exception is the birth control shot (Depo-Provera), which has been more consistently linked to weight gain. Here is a balanced, cited rundown by method.

What the research actually shows

Large evidence reviews, including Cochrane systematic reviews, have generally found no strong evidence that combined hormonal contraceptives (the pill, patch, ring) cause significant weight gain. Reviews of progestin-only methods reach broadly similar conclusions, with the clearest signal of weight gain seen with the injectable (Depo-Provera). ACOG and other authorities note that while individual people may notice weight changes, studies as a whole do not support the popular belief that most birth control reliably causes meaningful weight gain.

This matters because fear of weight gain leads some people to avoid effective contraception. Understanding the actual evidence — method by method — can support a better-informed choice with your provider.

The pill (combined and progestin-only)

For combined oral contraceptives, Cochrane reviews have not found evidence that they cause significant weight gain. Some people report mild, temporary fluid retention or bloating early on, which often settles. Progestin-only pills ("mini-pills") are similar in the evidence. If you notice a change, it is worth discussing, but the pill is not a reliable cause of major weight gain in the research.

Hormonal IUDs (Mirena, Kyleena, Liletta, Skyla)

Hormonal IUDs release a progestin locally in the uterus, with relatively low systemic hormone levels. Studies generally show little effect on weight for most users, though some people report changes. We cover this method in depth in Does Mirena cause weight gain?

Copper IUD (Paragard)

The copper IUD contains no hormones, so it is not expected to affect weight through hormonal mechanisms. It is often chosen by people who want to avoid hormonal effects entirely.

The implant (Nexplanon)

The etonogestrel implant is a progestin-only method placed under the skin of the upper arm. Weight gain is listed among reported side effects, and some users report it, but high-quality evidence that it causes major weight gain is limited. See our detailed page: Does Nexplanon cause weight gain?

The shot (Depo-Provera)

The injectable contraceptive depot medroxyprogesterone acetate (DMPA, Depo-Provera) is the method most consistently associated with weight gain in the research. Reviews have found that some users do gain weight on the shot, and the product information acknowledges weight gain as a possible effect. If weight is a concern for you, this is the method most worth discussing carefully with your provider.

Patch and ring

Like the combined pill, the patch and vaginal ring deliver combined hormones, and evidence reviews have not shown that they reliably cause significant weight gain. Individual experiences vary.

Quick-reference table

Summarized from Cochrane reviews, ACOG, and product information; see References. Individual experiences vary.

Why it can feel like birth control causes weight gain

• Timing overlaps with life changes. Many people start contraception in their late teens and twenties, a period when weight naturally tends to rise regardless of birth control.
• Fluid retention. Some methods can cause mild, temporary bloating early on that feels like weight gain but is not fat.
• Individual variation. A minority of people do report real changes; population studies just don't show it as a reliable, across-the-board effect.

Mustafa Bilgic

Operator of WeightGain.us, based in Adıyaman, Türkiye. Mustafa is an independent publisher, not a medical professional; every clinical statement here is attributed to the cited authorities (ACOG, Mayo Clinic, MedlinePlus/NIH, Cochrane, Planned Parenthood). For personal contraceptive advice, consult your own doctor.

Frequently asked questions

Does birth control cause weight gain?

For most hormonal methods, large reviews have not found strong evidence of significant weight gain. The clearest exception is the birth control shot (Depo-Provera), which is more consistently linked to weight gain. Individual experiences can vary.

Which birth control is most likely to cause weight gain?

The injectable contraceptive (Depo-Provera) is the method most consistently associated with weight gain in research. Other methods, including the pill, patch, ring, and hormonal IUD, do not show strong evidence of significant weight gain.

Which birth control is least likely to affect weight?

The non-hormonal copper IUD (Paragard) has no hormonal weight effect. The combined pill, patch, ring, and hormonal IUDs also lack strong evidence of significant weight gain for most people.

Can the pill make me bloated?

Some people experience mild, temporary fluid retention or bloating when starting the pill, which often settles within a few cycles. This is not the same as gaining fat, and studies do not show the pill reliably causes significant weight gain.

Should I avoid birth control because of weight gain?

For most methods, the evidence does not support avoiding contraception over weight concerns. If weight is important to you, discuss it with your provider, who can help you choose a method that fits your needs and effectiveness goals.

Related guides

References

Sources: ACOG — Combined Hormonal Birth Control · Mayo Clinic — Birth control pill FAQ · Cochrane — Combination contraceptives and weight · MedlinePlus (NIH) — Birth Control · Planned Parenthood — Birth Control.