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Does Birth Control Make Your Breasts Bigger? Flo Investigates

The birth control pill is a popular method of contraception for women around the world. Not only does it help prevent unwanted pregnancies, but it also can help regulate hormonal imbalances that may cause uncomfortable symptoms like heavy periods, painful cramps, PMS, and acne, but does birth control influence breast growth?
A woman holding doughnuts next to her breasts

Can birth control make your breasts bigger?

A woman’s breasts start developing during puberty, between the ages of 8 and 14. This happens due to hormonal changes, especially estrogen and growth hormone. Estrogen, when produced by the ovaries during puberty, leads to fat collecting in the connective tissues around the chest, which enlarges the breasts. At the same time, the duct system begins to grow. After menarche (the first period) and when a girl starts to ovulate, secretory glands start to form and grow. Breast maturation and growth continues for several years before reaching full size by the end of the teen years, in most cases. 

As an adult, your breast size may change with physiological changes in your body, like during your menstrual cycle or during pregnancy and breastfeeding

Even though breasts come in all shapes and sizes (and nipples do, too), not every woman loves the breast size they have. Women with large breasts may wish for smaller breasts, while women with small breasts may wish they had larger ones. Those in the latter group may consider turning to birth control for bigger breasts.

The birth control pill is a chemical compound of estrogen and progestin — two reproductive hormones that contribute to shaping a woman’s hips and chest by changing the way fat is distributed throughout the body.

For those of us who are wondering does birth control pills make your breast bigger, there is some evidence to support that this might be true.

1. Weight gain

Some women gain weight while they’re on the pill — though there’s no way to tell for certain whether this is due specifically to the pill, or other lifestyle factors. There is no conclusive scientific evidence that the pill causes weight gain, but the subcutaneous fat tissues on a woman's body (around the hips, thighs, and breasts) contain a large number of estrogen receptors, which increases the concentration of fat in those areas.

2. Muscle mass

A study on how genetics influences muscle growth found that women who were on the pill gained substantially less muscle mass than women who were not taking it. Researchers specifically saw that the women on the pill had less of the muscle-growth hormone DHEA in their bloodstream. Generally speaking, the less lean muscle mass you have, the more likely you are to carry excess fat — though it doesn’t necessarily mean that the fat will be in the breast area.

3. Fluid retention

The estrogen in the birth control pill also impacts how a woman’s body metabolizes water, which can lead to increased water retention. There is the potential, then, that swelling from increased fluid in the body could affect breast size.

So, do birth control pills make your breasts bigger? They might, but there’s no guarantee.

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A bra and birth control pills which make your breasts bigger

Birth control can be comprised of any of about ten different kinds of synthetic progestins and two estrogen analogues designed to mimic the effects of estrogen and progesterone. When taken according to the instructions, the pill prevents the ovaries from releasing an egg every month so that you can have sex without the risk of pregnancy.

The synthetic estrogen compound used in the birth control pill is up to 10 times stronger and remains in the body far longer than naturally-occurring estrogen. A woman’s body contains a unique balance of natural hormones, so the effects of hormone-based contraceptives like the pill differ from woman to woman. The higher the dose of hormones, the more likely you are to experience physical side effects. 

You may notice a slight increase in breast size during the 21 days that you take the active pills, but the effects are not permanent. Even if you aren’t on the pill, you may notice changes in breast size depending on where you are in your menstrual cycle. When you’re ovulating, your cup size might increase and your breasts may feel tender or sore, which happens due to water retention. 

Is it safe to use birth control solely for breast enlargement? 

Although the birth control pill is considered a safe and effective method of contraception, it’s not without its risks. Some women experience unpleasant side effects from taking the pill, including: 

Since larger breasts are not always a side effect of taking birth control, it’s not a reliable method for enlarging your breasts. If you’re interested in taking the birth control pill, speak to your doctor to see if it’s right for you.

With that said, there are other ways you can change the appearance of your breast size: 

  • Practice weight lifting or strength training exercises that target the pectoral muscles in the chest.
  • Experiment with wearing different push-up bras during the day. Be sure not to wear a bra to bed, though. Rather than keeping your breasts perky and lifted, sleeping with a bra can reduce circulation to the breast tissues, cause skin irritation, and may even lead to a fungal infection!
  • Plastic surgery to have breast implants placed inside your breast, above or under the pectoral muscles.

The most natural way your breasts enlarge as an adult is during pregnancy and breastfeeding. Your breasts may start to increase in your first trimester (around 6 to 8 weeks pregnant) as they develop protective fat layers and milk glands. Once you’ve given birth, your breasts will produce milk, which will make them larger. 

Of course, we’re certainly not suggesting you get pregnant just to enjoy larger breasts, but it can be a pleasant side effect if you’ve always wanted bigger breasts. 

We set out to investigate the question ‘does birth control make your breasts grow?’ By now, you know that birth control makes breasts bigger for some women, but the effects are temporary and likely just a result of increased fluid retention.

https://www.plannedparenthood.org/learn/birth-control/birth-control-pill/what-are-the-benefits-of-the-birth-control-pill

http://www.bbc.com/future/story/20181003-does-the-birth-control-pill-make-you-fat

http://www.bbc.com/future/story/20180822-the-birth-control-pill-can-have-male-side-effects

https://www.hopkinsmedicine.org/healthlibrary/conditions/breast_health/normal_breast_development_and_changes_85,P00151

https://goaskalice.columbia.edu/answered-questions/does-taking-pill-increase-size-your-breasts

https://www.healthline.com/health/birth-control/does-birth-control-make-your-boobs-bigger#when-to-see-a-doctor

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827491/

https://www.hopkinsmedicine.org/healthlibrary/conditions/breast_health/normal_breast_development_and_changes_85,P00151

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