Depo Provera is the main injectable contraceptive used in the UK*. It contains medroxyprogesterone acetate 150mg. It is given via in intramuscular injection every 12 weeks. It can however be given up to 14 weeks after the last dose without the need for extra precautions**

The main method of action is by inhibiting ovulation. Secondary effects include cervical mucus thickening and endometrial thinning.

Disadvantages include the fact that the injection cannot be reversed once given. There is also a potential delayed return to fertility (maybe up to 12 months)

Adverse effects

• irregular bleeding
• weight gain
• may potentially increased risk of osteoporosis: should only be used in adolescents if no other method of contraception is suitable
• not quickly reversible and fertility may return after a varying time

Contraindications

• breast cancer: current breast cancer is UKMEC 4, past breast cancer is UKMEC 3
• Noristerat, the other injectable contraceptive licensed in the UK, is rarely used in clinical practice. It is given every 8 weeks
• *the BNF gives different advice, stating a pregnancy test should be done if the interval is greater than 12 weeks and 5 days - this is however not commonly adhered to in the family planning community