What are the side effects of medroxyprogesterone (a progestin hormone)?

Side Effects of Medroxyprogesterone

Medroxyprogesterone acetate has significant side effects including menstrual irregularities, weight gain, bone mineral density loss, and mood changes that should be thoroughly discussed with patients before initiation. 1, 2

Common Side Effects

Menstrual Changes

• Irregular vaginal bleeding, spotting, or complete absence of menstrual periods (amenorrhea) are the most frequently reported side effects 1
• 55% of women report no menstrual bleeding after one year of use, and 68% report no bleeding after two years 1
• Changes in normal menstrual cycle may include irregular or unpredictable bleeding, increased or decreased menstrual bleeding, or complete cessation of bleeding 1

Weight Changes

• Weight gain occurs in approximately two-thirds of women using DMPA 1
• Average weight gain is about 5 pounds during the first year and 8 pounds over two years of use 1
• Weight gain at 6 months is a strong predictor of future excessive weight gain with ongoing DMPA use 3

Bone Health Concerns

• DMPA causes reductions in bone mineral density (BMD) 3
• The FDA has issued a black-box warning about the risk of decreased BMD among DMPA users 3
• Substantial recovery of BMD occurs after discontinuation of DMPA 3
• Calcium intake (1300 mg daily) and vitamin D (600 IU daily) supplementation are recommended for all patients on DMPA 3

Other Common Side Effects

• Abdominal pain and discomfort 1, 2
• Headaches 1, 2
• Weakness and fatigue 1, 2
• Nervousness and dizziness 1, 2
• Depression 2
• Hair loss or hair growth 2
• Decreased libido 4

Serious Side Effects

Cardiovascular Risks

• Possible increased risk of blood clots in arms, legs, lungs, and eyes 1
• Potential risk of stroke 1
• Women using DMPA should be monitored for signs of thromboembolism 3

Bone Health Risks

• Teenage years are the most important for bone strength development, making DMPA's effect on BMD particularly concerning for adolescents 1
• Higher risk for bone issues in patients with: bone disease, eating disorders, strong family history of osteoporosis, or those taking medications that lower calcium in bones 1
• ACOG does not advise limiting DMPA use to 2 years, recognizing the risk of unwanted pregnancy if contraceptive options are limited 3

Other Serious Concerns

• Possible increased risk of breast cancer 1
• Risk of ectopic pregnancy if pregnancy occurs while using DMPA 1
• Severe allergic reactions (rare) 1

Special Considerations

For Transgender Care

• When used in transgender care, progestins like medroxyprogesterone acetate can suppress testosterone levels via central feedback 3
• Not recommended by the Endocrine Society for transgender care due to risk of breast cancer, thromboembolism, and stroke 3

For Women with PCOS

• Medroxyprogesterone acetate suppresses circulating androgen levels and pituitary gonadotropin levels in women with PCOS 3
• Can be used to prevent endometrial cancer in women with PCOS, though optimal dosing and frequency are not established 3

Management of Side Effects

Menstrual Irregularities

• Counseling before initiation about expected menstrual changes improves continuation rates 3
• NSAIDs can be used for short-term treatment (5-7 days) of heavy menstrual bleeding 5
• For prolonged amenorrhea following DMPA use, return to fertility typically takes 9-18 months after discontinuation 6

Weight Management

• Regular monitoring of weight and discussing lifestyle modifications may help manage weight gain 3
• Consider alternative contraceptive methods if significant weight gain occurs within first 6 months 3

Bone Health

• Regular weight-bearing exercise is recommended 3
• Calcium (1300 mg daily) and vitamin D (600 IU daily) supplementation 3
• Consider bone density testing for patients with risk factors who use DMPA long-term 1

Clinical Recommendations

• Thorough pre-treatment counseling about potential side effects significantly improves continuation rates 3
• Schedule follow-up visits every 11-12 weeks for adolescents (rather than every 13 weeks) to allow for missed or delayed visits 3
• Consider alternative contraceptive methods if side effects are intolerable or for patients with specific risk factors 1
• For patients concerned about amenorrhea, switching to combined hormonal contraceptives may restore cyclic bleeding 7

Common Pitfalls to Avoid

• Failing to counsel patients about expected menstrual changes before initiating DMPA 3
• Not monitoring weight changes, especially during the first 6 months of use 3
• Overlooking the importance of calcium and vitamin D supplementation for bone health 3
• Discontinuing DMPA without discussing alternative contraceptive methods 1