Chapter 5 Download Chapter

Side Effects, Health Benefits, and Health Risks

Side Effects (see Managing Any Problems)

Some users report the following:

  • Changes in bleeding patterns,† including:
    • Lighter bleeding and fewer days of bleeding
    • Irregular bleeding
    • Infrequent bleeding
    • Prolonged bleeding
    • No monthly bleeding
  • Weight gain
  • Headaches
  • Dizziness
  • Breast tenderness

Bleeding changes are normal and not harmful. If a woman finds them bothersome, counseling and support can help.

Known Health Benefits and Health Risks

Long-term studies of monthly injectables are limited, but researchers expect that their health benefits and health risks are similar to those of combined oral contraceptives (see Chapter 1 – Combined Oral Contraceptives, Health Benefits and Health Risks). There may be some differences in the effects on the liver, however (see Question 2).

† For definitions of bleeding patterns, see “vaginal bleeding” in the Glossary.