According to a study in the American Journal of Obstetrics and Gynecology, women using the birth control shot gained an average of 5 kg and increased their body fat by 3.4 percent over 3 years.The rate of weight gain slowed over time.
The contraceptive is injected every 3 months, and is relatively inexpensive compared to other forms of birth control, and has a low failure rate. The shot’s link to increased abdominal fat, might increase the risk of cardiovascular disease, stroke and diabetes. The shot’s users were more than twice as likely as women using non-hormonal or oral birth control to become obese over the next three years.
In ongoing research, preliminary data has shown that about 25 % of women on the birth control shot experience significant and potentially dangerous body composition changes.
Women using oral contraception (the pill) did not gain more weight than those using a non-hormonal form of birth control (condoms, abstinence, etc.). However, the study found that their body fat increased slightly and their lean body mass (muscle) decreased. The study said this was not as likely among those women who exercised regularly and consumed a healthy diet that included increased protein intake.