Which birth control method is associated with the least weight gain and which is associated with the most weight gain?

Weight Gain and Birth Control Methods

Direct Answer

Copper IUDs and barrier methods (condoms, diaphragms) cause the least weight gain—essentially none—while depot medroxyprogesterone acetate (DMPA/Depo-Provera) causes the most weight gain among all contraceptive methods. 1, 2, 3

Methods with Minimal to No Weight Gain

Copper IUD (Most Weight-Neutral)

• The copper IUD is the most weight-neutral contraceptive option available, with no hormonal exposure and no association with weight gain. 1, 4
• Copper IUD users experience approximately the same weight gain as the average female population—which is age-related weight gain unrelated to contraception. 4, 5
• In a 7-year study of copper IUD users, women gained an average of 3.9 kg over 7 years, consistent with normal age-related weight changes in reproductive-age women. 5

Barrier Methods (Condoms, Diaphragms)

• Barrier methods have no hormonal effects on weight whatsoever and provide complete freedom from metabolic effects. 1, 4
• These methods are entirely weight-neutral but have lower contraceptive efficacy (18-28% pregnancy rates per year with typical use). 1

Combined Oral Contraceptives (COCs)

• Combined oral contraceptives do not cause clinically significant weight gain, according to American Academy of Pediatrics guidelines. 2
• Neither weight gain nor mood changes have been reliably linked to combined hormonal contraception. 2
• Women with obesity are generally not more likely to gain weight with COCs compared to their normal-weight peers. 2, 4

Contraceptive Vaginal Ring

• There is no clear evidence of significant weight change associated with the etonogestrel/ethinyl estradiol vaginal ring. 4, 6
• The ring releases 0.12 mg/day of etonogestrel and 0.015 mg/day of ethinyl estradiol. 6

Methods with Moderate Weight Effects

Levonorgestrel IUDs (Mirena, Skyla, Kyleena)

• Hormonal IUDs may affect body composition, with a 2.5% increase in body fat mass and a 1.4% decrease in lean body mass compared to copper IUD users. 4
• However, whether hormonal IUDs are truly weight-neutral requires additional investigation, as the overall weight change evidence remains unclear. 4

Contraceptive Implants

• Limited evidence suggests modest weight gain with implants, though data are mixed. 7
• Two studies showed the six-capsule implant group had greater weight gain (0.47-1.10 kg) compared to copper IUD users or barrier method users. 7

Method with Most Weight Gain

DMPA (Depo-Provera) - Highest Weight Gain Risk

DMPA is consistently associated with the greatest weight gain among all contraceptive methods and should be avoided when weight is a primary concern. 1, 2

Documented Weight Gain with DMPA:

• Women who completed 1 year of DMPA therapy gained an average of 5.4 lb (2.5 kg). 3
• Women who completed 2 years gained an average of 8.1 lb (3.7 kg). 3
• Women who completed 4 years gained an average of 13.8 lb (6.3 kg). 3
• Women who completed 6 years gained an average of 16.5 lb (7.5 kg). 3
• Two percent of women withdrew from clinical trials specifically because of excessive weight gain. 3

Critical 6-Month Checkpoint:

• Weight gain status at 6 months is a strong predictor of future excessive weight gain with ongoing DMPA use. 2
• Among adolescent users, 21% gained >5% body weight at 6 months, and these "early gainers" experienced a mean BMI increase of 7.6 versus 2.3 in non-early gainers over 18 months. 2
• If a patient gains >5% body weight at 6 months on DMPA, strongly consider switching to an alternative method. 2

Body Composition Changes with DMPA:

• Adolescents using DMPA had an 11% greater increase in body fat compared to those not using hormonal methods. 7
• DMPA users also had a 4% greater decrease in lean body mass. 7

High-Risk Populations for DMPA Weight Gain:

• Adolescents with obesity who use DMPA are at higher risk for weight gain compared to normal-weight DMPA users, normal-weight non-users, and obese COC users. 2, 4

Clinical Counseling Approach

For Weight-Conscious Patients:

• Recommend copper IUD or barrier methods as first-line options if weight gain is the primary concern. 1
• If hormonal contraception is preferred, recommend combined oral contraceptives with ≤35 μg ethinyl estradiol. 1, 2

Baseline Documentation:

• Measure baseline weight and BMI at contraceptive initiation to facilitate future discussions about weight changes, though this is not required for medical eligibility. 8, 2

Common Pitfall to Avoid:

• Do not discontinue effective contraception based on weight misperceptions, as the risk of unintended pregnancy far outweighs minimal or nonexistent weight effects from most contraceptives. 2
• Reproductive-aged women gain weight more rapidly than other age groups (average 6.3 kg over 10 years) independent of contraceptive use. 4