Weight gain is the most commonly reported side effect of the combined Pill – the most popular type, which contains oestrogen and progesterone.
Some studies oppose the theory that hormonal birth control causes weight gain. But still, some people report gaining a few kilograms in the weeks and months after they start taking the Pill.
However, most experts say this is often temporary and the result of water retention, not actual weight gain.
Here are some reasons for weight gain while you are on a contraceptives:
Type of birth control:
According to WebMD, most birth control pills use the same type of oestrogen in various doses, but each brand of pill may offer a slightly different type of the hormone progestin, at different doses. The result? Potentially different side effects.
Oestrogen in high doses can cause weight gain due to increased appetite and fluid retention. So, 50 years ago they may indeed have caused weight gain in some women. Whichever one you try, give it at least three months for any side effects to pass.
Water retention:
Pandia Health says excess oestrogen in birth control pills is the primary vehicle for preventing ovulation and making the body think it has already conceived. But oestrogen causes the body to retain water.
In most cases, birth control can promote water retention, which increases the number on the scale and also gives the appearance of excess weight.
Water retention occurs when renin-angiotensin, a compound that the kidneys create, is stimulated via excess oestrogen circulating throughout the body. The higher the amount of oestrogen in a birth control pill, the more water a woman will retain while taking the pill, but the weight may flush away with your first period.
Older forms of birth control
Singlecare explains that many of the misconceptions about birth control and weight gain began as a result of older birth control pills that contained higher levels ofo estrogen hormones.
One study found that birth control pills developed in the 1950s contained 150 micrograms (mcg) of theo estrogen mestranol—whereas newer low-dose birth control pills only contain lower levels of oestrogen (20-50mcg).
If you’re concerned, talk to your health-care provider about low-dose options.