Medroxyprogesterone Injection for Contraception

Medroxyprogesterone acetate injections, marketed as

Depo-Provera

and

Sayana Press

, are long-acting reversible contraceptives (LARC) providing highly effective pregnancy prevention for up to 12-13 weeks per dose. These progestogen-only injections inhibit ovulation, thicken cervical mucus, and thin the uterine lining, offering a convenient option for women seeking reliable birth control without daily compliance.

About Medroxyprogesterone Injection for Contraception

Medroxyprogesterone injections deliver a synthetic progestin that mimics progesterone, suppressing the hormonal signals needed for ovulation.

Depo-Provera

is administered intramuscularly (150 mg) into the buttock or upper arm, while

Sayana Press

is a lower-dose (104 mg) subcutaneous version for self-injection into the thigh or abdomen. Both prevent pregnancy for approximately three months, with Depo-Provera effective for at least 12 weeks (±5 days) and Sayana Press up to 13 weeks.

Introduced decades ago, these injections have a proven safety profile from extensive clinical use worldwide. They are ideal for women who cannot use estrogen-containing methods due to risks like blood clots. First-year failure rates are low at about 0.3%, making them more effective than pills or condoms when used correctly.

Key benefits include no daily action required, reduced menstrual bleeding over time, and protection against endometrial and ovarian cancers. However, users must commit to quarterly clinic visits or self-administration schedules.

Key Facts

• **Highly effective**: Over 99% with perfect use; prevents ovulation in most cycles.
• **Duration**: 12-13 weeks protection per injection.
• **No estrogen**: Safe for breastfeeding mothers and those with estrogen contraindications.
• **Return to fertility**: Delayed up to 12 months after last dose; counsel women planning pregnancy.
• **Bone health**: Long-term use may reduce bone mineral density (BMD); monitor in adolescents and perimenopausal women.

Types of Medroxyprogesterone Injection

Brand	Dose	Route	Administration	Duration
Depo-Provera	150 mg	Intramuscular (IM)	Healthcare provider (buttock/deltoid)	12 weeks (±5 days)
Sayana Press	104 mg	Subcutaneous (SC)	Self-injection (thigh/abdomen)	13 weeks

**Depo-Provera** requires professional administration every 12 weeks, ensuring precise dosing.

Sayana Press

, a prefilled syringe, empowers self-use, improving access in remote areas.

How Medroxyprogesterone Injections Work

These injections release medroxyprogesterone acetate slowly from the injection site, exerting anti-estrogenic, anti-androgenic, and antigonadotrophic effects. Primary mechanisms include:

• Inhibiting gonadotropin secretion, preventing ovulation.
• Thickening cervical mucus to block sperm.
• Thinning endometrial lining, reducing implantation chances.

Effects begin within days if timed correctly with the menstrual cycle, providing immediate or near-immediate protection.

Dosage and Administration

**First injection timing**:

• Within first 5 days of menstrual cycle: Immediate protection.
• Days 6-30: Use backup contraception for 7 days.
• Postpartum (non-breastfeeding): Within 5 days of delivery.
• Breastfeeding: After 6 weeks postpartum.

**Subsequent doses**: Every 12 weeks for Depo-Provera (max 13 weeks +2 days tolerated in some cases); 13 weeks for Sayana Press. Late injections require pregnancy tests and backup methods.

**Switching methods**:

• From combined pill: Within 7 days of last pill.
• From implant/IUD: Time with removal.

Sayana Press self-injection: Clean site, pinch skin, insert needle at 45-90 degrees, depress plunger fully.

Who Can Use Medroxyprogesterone Injections (and Who Can’t)

Suitable for most women post-puberty, including smokers over 35 (unlike estrogen methods). Ideal for those with heavy periods, sickle cell disease, or epilepsy.

Contraindications

• Current/past breast cancer.
• Undiagnosed vaginal bleeding.
• Severe liver disease.
• Pregnancy (though not teratogenic).
• Hypersensitivity to medroxyprogesterone.

Use caution in adolescents, long-term users (>2 years), and those with osteoporosis risk factors.

Side Effects and Risks

Common initial effects: Irregular bleeding (50-70% in first year), weight gain (average 2-5 kg/year), headaches.

• **Menstrual changes**: Amenorrhea in 55% by year 1; spotting common early.
• **Bone density**: Loss of 5-7% BMD with prolonged use; reversible but monitor.
• **Weight gain**: Counsel on lifestyle; reversible post-discontinuation.
• **Mood/depression**: Rare; discontinue if severe.
• **Rare serious**: Ectopic pregnancy risk if failure occurs; no increased breast cancer risk.

Bone Health and Long-Term Use

Long-term Depo-Provera use suppresses estrogen, leading to BMD loss, especially in teens (up to 7% over 5 years). WHO recommends against use >2 years unless no alternatives; calcium/vitamin D advised. BMD recovers post-stopping, but peak bone mass concerns in youth.

Pregnancy, Breastfeeding, and Fertility

Pregnancy: Rule out before each dose; effective if failure (lowest ectopic risk among failures).

Breastfeeding: Safe from 6 weeks postpartum; minimal milk impact.

Return to fertility: Ovulation resumes in 83% within 12 months of last injection (mean 5-10 months); pregnancies reported as early as 14 weeks post-dose.

Interactions with Other Medicines

No major interactions, but enzyme inducers (rifampicin, anticonvulsants) may reduce efficacy; use backup. Avoid long-term estrogen co-administration.

Stopping Medroxyprogesterone Injections and Return to Fertility

Stop anytime; no washout needed. Fertility returns variably (4-31 months median 10); advise alternatives if pregnancy desired soon.

Alternatives to Medroxyprogesterone Injections

Method	Effectiveness	User Task	Key Pros
Implant (Nexplanon)	>99%	Every 3 years	Bleeding changes; reversible
IUD (Mirena)	>99%	Every 5 years	Reduces bleeding
Pill	91-99%	Daily	Regulates cycles
Condom	82-98%	Per use	STI protection

Frequently Asked Questions (FAQs)

Q: How soon after Depo-Provera injection am I protected?

A: Immediately if within first 5 days of cycle; otherwise, use backup for 7 days.

Q: Does Sayana Press hurt to self-inject?

A: Mild discomfort possible; smaller needle than Depo-Provera. Practice with provider first.

Q: Will periods return normally after stopping?

A: Most resume within 12 months; some irregular initially.

Q: Can it cause infertility?

A: No permanent effect; delay up to 1 year average.

Q: Is weight gain inevitable?

A: Common but variable; diet/exercise mitigate.

Q: Safe for teens?

A: Yes short-term, but monitor bone health; limit if possible.