Birth Control Health Center

Birth Control Pills and Weight Gain

The birth control pill was a big hit when it went on sale in the early 1960s. Nearly 50 years later it's still one of the most popular methods of reversible birth control, with dozens of brands and formulations available.

And, as with any celebrity, half-truths and misconceptions have attached themselves to the pill. Perhaps none are more lingering than the myth that birth control pills can lead to weight gain.

What’s the truth about birth control pills and weight gain?

Birth Control Pills and (Very Little) Weight Gain

All medications can have side effects for some of the people using them. Aspirin may cause heartburn. Cough medicines can make some people sleepy. The most common birth control pill side effects are breakthrough bleeding, breast tenderness, nausea, and headache.

For a few women, the pill may cause some weight gain, often due to fluid retention. But not significant amounts, and not for most women. Indeed, a review of 44 studies showed no evidence that birth control pills caused weight gain in most users. And, as with other possible side effects of the pill, the minimal weight gain is generally temporary, going away within two to three months.

While weight gain is an uncommon and temporary side effect to the pill, if you happen to be one of those few women who put on pounds, talk to your doctor. Your doctor may suggest a different type of birth control pill. Why? Because all pills are not the same.

There are two types of birth control pill: combination pills, which contain estrogen and progestin, and progestin-only pills. While most birth control pills use the same type of estrogen in various doses, the progestin formulation in each can differ. This means that each brand of pill may offer a slightly different type of the hormone, at different doses. The result? Potentially different side effects.

Whichever pill you try, remember to give it at least three months for any side effects to pass.

How Did the Myth About the Pill and Weight Gain Get Started?

When birth control pills were first sold in the early 1960s, they had very high levels of estrogen and progestin, nearly 1,000 times more hormones than most women needed! And there’s the clue. Estrogen in high doses can cause weight gain due to increased appetite and fluid retention. So 50 years ago the pill may indeed have caused weight gain in some women.

Today's birth control pills have much lower amounts of hormones. The pill remains one of the most effective forms of birth control available when used correctly.