Depo-Provera injection

Depo-Provera (depot medroxyprogesterone acetate, or DMPA) is a progestin injection given every 11 to 13 weeks, typically into the upper arm or hip muscle. A subcutaneous version (Depo-SubQ Provera 104) is also available. Each shot delivers a high dose of medroxyprogesterone designed to maintain suppressive blood levels for the full interval.

Typical-use efficacy is around 96%, perfect-use above 99%. The gap reflects late or missed shots.

This is informational, not medical advice. Contraceptive choice should be discussed with a qualified provider.

How it works

Depo-Provera produces sustained progestin levels that:

  1. Suppress ovulation by inhibiting the LH surge through HPO axis suppression. The dominant mechanism, more complete than the mini-pill.
  2. Thicken cervical mucus.
  3. Thin the endometrium.

Ovulation suppression is strong and reliable across the 11 to 13 week interval, which is why dosing tolerance is fairly forgiving compared to daily oral methods.

Cycle implications

Depo is one of the most cycle-suppressive contraceptives. For most users, the menstrual cycle is essentially absent: no follicular phase, no ovulation, no luteal phase, no progesterone rise (the synthetic progestin is constant, not cyclic).

Bleeding patterns:

  • About 50% of users have irregular spotting in the first year.
  • By the end of the first year, around 50% stop bleeding entirely (amenorrhea), and this rises to 70% by 2 years.

Cycle syncing by hormonal phase does not apply. The structural 28-day rotation can still be used as a productivity framework, but the biology underneath it is paused.

Slow cycle return after stopping

The single most distinctive feature of Depo, and a frequent surprise to users, is the slow return of fertility and ovulation after discontinuation. Unlike pills, where ovulation often returns within weeks, Depo can suppress ovulation for 6 to 18 months after the last shot. Median time to conception after discontinuation is roughly 9 to 10 months.

This is not an indication of permanent harm; cycles do return for the large majority. But users planning conception within the next year should consider a different method.

Common side effects

  • Irregular bleeding or amenorrhea.
  • Weight gain. Depo is the contraceptive most consistently associated with weight gain at the population level, averaging 4 to 5 lbs in the first year for users prone to it.
  • Mood changes, including depression in a subset of users.
  • Decreased libido.
  • Headaches.
  • Acne.
  • Bone density loss. Reversible after discontinuation, but the FDA has a boxed warning recommending no more than 2 years of use unless other methods are unsuitable. Particularly relevant in adolescents (peak bone-building years) and users with osteoporosis risk factors.

When to consider

  • Want highly effective contraception with infrequent administration (4 shots per year).
  • Difficulty with daily pills or with the idea of a long-term implant or IUD.
  • Estrogen is contraindicated.
  • Heavy bleeding or endometriosis pain that may respond to ovulation suppression.

When NOT to consider

  • Planning to conceive within the next 12 to 18 months.
  • History of bone density issues, eating disorders, or low bone mass.
  • History of significant depression that worsens on hormonal contraception.
  • Concerned about weight changes.

Related reading