Side Effects, Health Benefits, and Health Risks

Side Effects (see Managing Any Problems)

Most users report some changes in monthly bleeding. †

  • Woman receiving progestion-Only InjectablesWith DMPA, these typically include: 

    First 3 months:

    • Irregular bleeding
    • Prolonged bleeding

    At and after 1 year:

    • No monthly bleeding
    • Infrequent bleeding
    • Irregular bleeding
  • With NET-EN, bleeding patterns are less affected than with DMPA

    First 6 months:

    • Fewer days of bleeding

    After 1 year:

    • More likely to have monthly bleeding than DMPA users. 

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

Some users report the following side effects:

  • Weight gain (see Question 5)
  • Headaches
  • Dizziness
  • Abdominal bloating and discomfort
  • Mood changes

Other possible physical changes:

  • Loss of bone density (largely reversible, see Question 11)
Why Some Women Say They Like Progestin-Only Injectables
  • Requires action only every 2 or 3 months. No daily pill-taking.
  • Does not interfere with sex    
  • Private: No one else can tell that a woman is using contraception
  • Stop monthly bleeding (for many women)      
  • May help women to gain weight     

Known Health Benefits

Known Health Risks

DMPA

Help protect against:

  • Pregnancy and associated risks
  • Cancer of the lining of the uterus (endometrial cancer)
  • Uterine fibroids

May help protect against:

  • Iron-deficiency anemia

Reduces:

  • Sickle cell crises among women with sickle cell anemia
  • Symptoms of endometriosis (pelvic pain, irregular bleeding)

 

None

NET-EN*

Helps protect against:

  • Pregnancy and associated risks
  • Iron-deficiency anemia

 

None

* NET-EN may also offer many of the other health benefits that DMPA offers, but this list of benefits includes only those for which there is available research evidence.

DMPA for Subcutaneous Injection

DMPA is now available in a special formulation, called DMPA-SC, intended only for subcutaneous (SC) injection (just under the skin) and not for injection into muscle. Subcutaneous injection is easier to learn than intramuscular injection. 

DMPA-SC is available in 2 injection systems: in the Uniject device and in prefilled, single-dose, conventional syringes. Both have short needles meant for injection just below the skin.

With the Uniject system, the user squeezes a flexible reservoir that pushes the fluid through the needle. DMPA-SC in the Uniject system is marketed under the brand name Sayana Press. This product may be particularly useful for community-based programs. Also, women can easily learn to self-inject DMPA-SC with this system (see the section in this chapter titled Self-Injection Can Be an Option, including the instructions for self-injection).

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