Provera is a prescription medication used primarily to treat irregular or absent periods, to manage abnormal uterine bleeding, and to protect the uterine lining in women taking estrogen therapy during menopause. The active ingredient is medroxyprogesterone acetate, a synthetic form of progesterone, one of the hormones that regulates the menstrual cycle and prepares the uterus for pregnancy each month.
How Provera Works
Your body naturally produces progesterone during the second half of your menstrual cycle. This hormone thickens and stabilizes the uterine lining. When progesterone levels drop at the end of the cycle, the lining sheds, and you get your period. Provera mimics this process. By delivering a synthetic version of progesterone, it supports the uterine lining while you take it, then triggers a controlled shedding (a withdrawal bleed) once you stop.
Because it’s a synthetic progestin, Provera interacts with several hormone receptors in the body beyond just the progesterone receptor. It also has some activity at receptors for androgens and glucocorticoids, which partly explains why it can cause side effects that natural progesterone typically does not.
Treating Absent Periods
One of Provera’s most common uses is treating secondary amenorrhea, the medical term for when your period stops for reasons other than pregnancy, menopause, or breastfeeding. This can happen due to stress, significant weight changes, hormonal imbalances like polycystic ovary syndrome (PCOS), or other conditions that disrupt ovulation.
A typical course involves taking Provera for 5 to 10 days. After you finish the last tablet, a withdrawal bleed should begin within 3 to 7 days, provided your body has been producing enough estrogen to build up the uterine lining beforehand. If no bleeding occurs, it can signal that estrogen levels are too low to thicken the lining in the first place, which gives your doctor useful diagnostic information about what’s going on.
Managing Abnormal Uterine Bleeding
Provera is also prescribed when periods are irregular, unusually heavy, or unpredictable. In many of these cases, the underlying issue is that ovulation isn’t happening regularly. Without ovulation, your body produces estrogen but not enough progesterone to balance it. The uterine lining keeps building without the normal hormonal signal to shed, leading to erratic or heavy bleeding when it finally breaks down on its own.
Taking Provera for a set number of days each month essentially replaces that missing progesterone signal. It stabilizes the lining during the treatment window, then allows a predictable, controlled bleed after you stop. This approach can also reduce the risk of endometrial hyperplasia, an overgrowth of the uterine lining that can develop when estrogen goes unopposed by progesterone for long stretches.
Protecting the Uterus During Menopause Therapy
For women going through menopause, estrogen therapy is one of the most effective treatments for symptoms like hot flashes, night sweats, and vaginal dryness. But taking estrogen alone when you still have a uterus stimulates the uterine lining and raises the risk of endometrial hyperplasia and, over time, endometrial cancer. Provera is added specifically to counteract this risk.
In menopausal hormone therapy, Provera can be taken in two ways. In a cyclical regimen, you take it for 10 to 14 days of each monthly cycle, which produces a regular withdrawal bleed similar to a period. In a continuous regimen, you take a lower dose every day alongside estrogen, which over time typically eliminates monthly bleeding altogether. Your doctor will choose the approach based on how far into menopause you are and your preferences around monthly bleeding.
Provera Is Not Birth Control
This is a point of real confusion because of the name similarity with Depo-Provera, the injectable contraceptive. Both contain the same active ingredient, medroxyprogesterone acetate, but they work very differently. The injection delivers a much higher, sustained dose that suppresses ovulation continuously for three months. Oral Provera tablets do not reliably prevent ovulation and are not approved for contraception.
The NHS states this plainly: medroxyprogesterone tablets do not work as contraception, and you could get pregnant while taking them. If you’re sexually active and not trying to conceive, you need a separate method of birth control while on Provera.
What to Expect: Side Effects
The most commonly reported side effects of oral Provera include breast pain or tenderness, headaches, and mood changes such as feeling down, irritable, or nervous. These tend to be most noticeable in the first cycle or two and often settle as your body adjusts. Bloating, mild nausea, and changes in appetite can also occur.
The mood-related side effects deserve particular attention. Some women notice increased irritability, low mood, or a general feeling of emotional flatness while taking Provera. These effects are linked to the way synthetic progestins interact with multiple hormone receptors in the brain. If mood changes are significant or persist, it’s worth discussing alternatives with your prescriber.
Weight Gain: Oral vs. Injectable
Concerns about weight gain come up frequently with Provera, but the evidence suggests this is largely an issue with the injectable form rather than the oral tablets. In clinical studies, the injectable version (Depo-Provera) was associated with an average weight gain of about 5.1 kilograms (roughly 11 pounds) over 36 months, with increases in both total body fat and central fat distribution. Oral formulations, by contrast, showed no significant weight change in the same studies. Some users of the injectable actually maintained or lost weight, but the overall trend was clearly toward gain with the shot, not the pill.
Bone Density Concerns
The FDA’s black box warning about bone mineral density loss applies specifically to the Depo-Provera injection, not to oral Provera tablets. The injection suppresses estrogen production for extended periods, which can thin bones over time, especially with use beyond two years. Oral Provera is taken in short courses or alongside estrogen therapy, so it does not carry the same bone density risk. If you’ve seen warnings about bone loss linked to medroxyprogesterone, they’re referring to the injectable form.
How Long You’ll Take It
The length of treatment depends entirely on why you’re taking Provera. For absent or irregular periods, a single course of 5 to 10 days may be all that’s needed, though some women take it cyclically for several months to establish a regular pattern. For menopause-related hormone therapy, treatment can continue for months or years, with periodic reassessment of whether the benefits still outweigh the risks.
Provera is not typically intended as a permanent medication for menstrual irregularities. In many cases, the underlying cause of missed or irregular periods, whether it’s a hormonal imbalance, weight issue, or stress-related disruption, is addressed alongside or after the Provera course. The medication essentially buys time and protects the uterine lining while the root problem is being sorted out.