Do hormonal contraceptives lead to weight gain?

DMPA users gain more weight in specific populations

For 18 months, researchers conducting a large prospective, nonrandomized study followed American adolescents ages 12 to 18 years who used DMPA and were classified as obese (defined as a baseline body mass index [BMI] >30 kg/m²) to determine how their weight gain compared with obese combined OC users and obese controls.²

Obese DMPA users gained significantly more weight (9.4 kg) than obese combined OC users (0.2 kg; P<.001) and obese controls (3.1 kg; P<.001). Of the 450 patients, 280 (62%) identified themselves as black and 170 (38%) identified themselves as nonblack.

In another retrospective cohort study of 379 adult women from a Brazilian public family planning clinic, current or past DMPA users were matched with copper T 30A intrauterine device users for age and baseline BMI and categorized into 3 groups: G1 (BMI <25 kg/m²), G2 (25-29.9 kg/m²), or G3 (≥30 kg/m²).³

Weight doesn’t appear to increase with combined oral contraception compared with nonhormonal contraception, but percent body fat may increase slightly.

At the end of the third year of use, the mean increase in weight for the normal weight group (G1) and the overweight group (G2) was greater in DMPA users than in DMPA nonusers (4.5 kg vs 1.2 kg in G1; P<.0107; 3.4 kg vs 0.2 kg in G2; P<.0001). In the obese group (G3), the difference in weight gain between DMPA users and DMPA nonusers was minimal (1.9 kg vs 0.6 kg; P=not significant).

One limitation of these 2 studies could be that the women under investigation were from defined populations—black urban adolescents and a public family planning service.