CHAPTER 4
Progestin-Only Injectables

Key Points for Providers and Clients

Bleeding changes are common but not harmful. Typically, irregular bleeding for the first several months and then no monthly bleeding.
Return for injections regularly. Coming back every 3 months (13 weeks) for DMPA or every 2 months for NET-EN is important for greatest effectiveness.
Injection can be as much as 4 weeks late for DMPA or 2 weeks late for NET-EN. Client should come back even if later.
Gradual weight gain is common.
Return of fertility is often delayed. It takes several months longer on average to become pregnant after stopping progestin-only injectables than after other methods.

What Are Progestin-Only Injectables?

The injectable contraceptives depot medroxyprogesterone acetate (DMPA) and norethisterone enanthate (NET-EN) each contain a progestin like the natural hormone progesterone in a woman's body. (In contrast, monthly injectables contain both estrogen and progestin. See Monthly Injectables.)
Do not contain estrogen, and so can be used throughout breastfeeding and by women who cannot use methods with estrogen.
DMPA, the most widely used progestin-only injectable, is also known as "the shot," "the jab," the injection, Depo, Depo-Provera, Megestron, and Petogen.
NET-EN is also known as norethindrone enanthate, Noristerat, and Syngestal. (See Comparing Injectables, for differences between DMPA and NET-EN.)

Progestin-Only Injectable Syringe and Vial

Given by injection into the muscle (intramuscular injection). The hormone is then released slowly into the bloodstream. A different formulation of DMPA can be injected just under the skin (subcutaneous injection). See New Formulation of DMPA.
Work primarily by preventing the release of eggs from the ovaries (ovulation).