Contraceptive injections are a form of long-acting reversible contraception (LARC) that provide protection against pregnancy for a certain period of time. Here are the common types of contraceptive injections:

1. Depo-Provera (Medroxyprogesterone Acetate or DMPA):
   • Duration: Provides protection for about 12-14 weeks.
   • Administration: Given as an intramuscular injection every 12 weeks.
   • Mechanism: Works by preventing ovulation, thickening cervical mucus, and thinning the lining of the uterus.
2. Sayana Press (Medroxyprogesterone Acetate or DMPA):
   • Duration: Similar to Depo-Provera, it provides protection for about 12-14 weeks.
   • Administration: This is a subcutaneous injection, meaning it is injected under the skin rather than into the muscle. It can be self-administered.
   • Mechanism: Same as Depo-Provera.
3. Noristerat (Norethisterone Enantate or NET-EN):
   • Duration: Provides protection for about 8 weeks.
   • Administration: Given as an intramuscular injection every 8 weeks.
   • Mechanism: Works primarily by preventing ovulation.

These injections are highly effective when administered correctly and on time. However, they do not protect against sexually transmitted infections (STIs), so additional protection (like condoms) may be necessary if there is a risk of STIs.