Hormone factors. although weight gain is a potential side effect of all birth control pills, some pills are more likely to cause weight gain than others 1.the synthetic hormones found in birth control pills and some other forms of contraception, such as the hormonal iud, are the biggest factor in weight gain 1.each type of birth control pill contains a different proportion and formulation of. Taking the birth control pill or another type of hormone based contraceptive is extremely common. i am asked a lot of questions from women, about weight loss and the birth control pill, if it affects their weight, health, hormones, etc.. €
