Progestin-only contraceptives: effects on weight.

Area of Science:

• Reproductive Health
• Pharmacology
• Clinical Research

Background:

• Progestin-only contraceptives (POCs) are suitable alternatives for individuals unable to use estrogen-containing methods.
• Available POCs include injectables, intrauterine devices, implants, and oral pills, offering long-acting and cost-effective pregnancy prevention.
• Concerns regarding weight gain are a significant barrier to POC initiation and a cause for early discontinuation.

Purpose of the Study:

• To evaluate the association between the use of progestin-only contraceptives (POCs) and changes in body weight.
• To analyze body composition changes in relation to POC usage.

Main Methods:

• A systematic review of comparative studies examining POCs against other contraceptive methods or no contraception.
• Inclusion of 22 studies (17 non-randomized, 5 RCTs) involving 11,450 women, assessing mean weight change and body composition.
• Data extraction and analysis using adjusted measures for non-randomized studies and mean differences/odds ratios for randomized controlled trials.

Main Results:

• Fifteen studies found no significant differences in weight or body composition between comparison groups.
• Five studies indicated differences, with depot medroxyprogesterone acetate (DMPA) users showing greater weight gain compared to copper IUC or no hormonal method.
• Some studies reported increased body fat and decreased lean body mass with DMPA, LNG-IUC, or desogestrel-containing pills compared to non-hormonal methods.

Conclusions:

• The overall quality of evidence is low, primarily due to a lack of randomization and high loss to follow-up.
• Limited evidence suggests minimal weight or body composition changes with most POCs, with mean weight gain typically under 2 kg in the first year.
• Counseling on expected weight changes can potentially mitigate contraceptive discontinuation due to user perceptions.