Short answer: Both contain medroxyprogesterone acetate, but their labels cover different uses.12 Depo-Provera CI is a 150 mg shot into a muscle every 3 months (13 weeks) to prevent pregnancy, with a boxed warning on bone loss. Provera is a 2.5, 5 or 10 mg tablet taken for some days a month for stopped periods or abnormal bleeding, or to protect the uterine lining during estrogen therapy.
| Depo-Provera CI | Provera | |
|---|---|---|
| Form | 150 mg/mL injection into the buttock or upper arm muscle, given by a healthcare professional1 | 2.5 mg, 5 mg and 10 mg tablets by mouth2 |
| Approved for | Preventing pregnancy1 | Secondary amenorrhea; abnormal uterine bleeding from hormonal imbalance; preventing endometrial hyperplasia with daily conjugated estrogens 0.625 mg after menopause2 |
| Schedule | 150 mg every 3 months (13 weeks)1 | 5 or 10 mg daily for 5 to 10 days, or for 12 to 14 days a month with estrogen2 |
| Most common in label trials | Irregular bleeding 57.3% at 12 months; no periods 55% at 12 months; weight gain over 10 lb at 24 months 37.7%1 | Taken alone: listed without percentages, such as bleeding changes, breast tenderness, nausea, headache and weight change2 |
| Late or missed dose | More than 13 weeks since the last shot: the physician confirms the patient is not pregnant first1 | No instruction in the label2 |
| Boxed warning | Loss of bone mineral density; not recommended beyond 2 years unless other methods are inadequate1 | Cardiovascular disorders, breast cancer and probable dementia with estrogen plus progestin therapy2 |
The dose and form set the job. Depo-Provera CI gives 150 mg in one injection that lasts 3 months and works mainly by preventing ovulation; its label says effectiveness depends on keeping to the schedule and that return of fertility is likely to be delayed, with a median time to conception of 10 months after the last shot.1 Provera gives a few milligrams a day for a short stretch, and withdrawal bleeding usually follows 3 to 7 days after stopping a course for stopped periods.2
Depo-Provera CI's boxed warning is about bone: bone density loss grows with longer use and may not fully reverse, which is why the label does not recommend it beyond 2 years unless other methods are inadequate.1 Provera's boxed warning comes from the Women's Health Initiative, where daily conjugated estrogens with medroxyprogesterone 2.5 mg raised the risk of blood clots, stroke, heart attack, invasive breast cancer and, in women 65 and older, probable dementia.2 Both labels list blood clots and breast cancer among reasons not to use them.12
Which, if either, fits is for your prescriber. More detail: Depo-Provera side effects, Provera side effects, the Depo-Provera and Provera dosing schedules, the Depo-Provera missed-dose page, how to store Depo-Provera and Prempro vs Activella: how do the two combined HRT tablets differ?.