How Provera May Help Your Menstrual Cycle

Provera may be prescribed for several reasons, most commonly to treat heavy menstrual periods or stopped periods (amenorrhea) that are due to an underlying hormone problem. Provera (medroxyprogesterone) is a synthetic form of progesterone—a hormone naturally produced after ovulation (when an egg is released from an ovary).

In addition, Provera is sometimes combined with estrogen to treat menopausal-related symptoms (for example, hot flashes) in postmenopausal women who have a uterus. In this case, the purpose of Provera is to prevent the thickening of the uterine lining, which can lead to uterine cancer. Provera can also be used in a progesterone challenge test.

Secondary Amenorrhea

Secondary amenorrhea occurs when a woman stops having regular periods for more than three months (when they used to be regular) or more than six months (if they used to be irregular). There are a number of potential causes of secondary amenorrhea including:

• Pregnancy
• Thyroid disease
• Polycystic ovarian syndrome
• A high prolactin level
• Hypothalamic amenorrhea: a condition that may develop as a result of stress, excessive weight loss, or strenuous exercise

In order to find the cause of a woman's secondary amenorrhea, a doctor will order a number of tests like a pregnancy test, blood hormone levels, and a progesterone challenge test (also called a progesterone withdrawal test).

In the progesterone challenge test, a woman may be prescribed 5 milligrams or 10 milligrams of Provera for five to 10 days to see if she experiences vaginal bleeding. If a woman does not experience vaginal bleeding within two weeks of taking Provera, then either she has very low estrogen levels in her body or she has an outflow tract disorder, like Asherman's syndrome.

If a woman experiences vaginal bleeding (which usually occurs within three to seven days of stopping Provera) then she has enough estrogen in her body, thus her amenorrhea is from not ovulating (called anovulation). In this case, the doctor will then perform more tests to determine the reason for her anovulation.

Abnormal Uterine Bleeding

If a woman has chronic anovulation, she may develop abnormal uterine bleeding, which is either irregular or excessive menstrual bleeding.

Polycystic ovary syndrome (PCOS) is a classic example of a condition that often causes irregular menstruation from chronic anovulation. Polycystic ovary syndrome is the most common endocrine disorder in women of childbearing age. Two hallmark features of PCOS are irregular periods and high levels of androgens (such as testosterone), which contribute to the development of acne and hirsutism. Metabolic problems such as obesity and insulin resistance are also common in PCOS.

Usually, a combination estrogen-progestin contraceptive (for example, "the Pill") is recommended for women with PCOS, to regulate a woman's menstrual cycles, protect the uterine lining from overgrowth, and also treat the effects of having high androgen levels (for example, acne).

For women who cannot take or choose not to take a combined estrogen-progestin contraceptive, Provera is an option. Provera works by preventing the overgrowth of tissue in the uterine lining.

Hormone Replacement Therapy

Provera may also be used in combination with estrogen in postmenopausal women with a uterus. The combination of estrogen and progesterone is called hormone replacement therapy and its purpose is to treat menopause-related symptoms like hot flashes.

The purpose of the progesterone in addition to the estrogen is to prevent thickening of the uterus. This is why progesterone is only given to women who still have a uterus. Either Provera or natural progesterone (more commonly) is prescribed.

Hormone replacement therapy should be used at the lowest effective dose and for the shortest time possible, assuming a woman's risk and the benefits of taking hormone replacement therapy have been thoroughly weighed and discussed.

What to Expect From Provera

Since Provera is a hormone, it may cause side effects. The most common ones are headaches, nausea, breast tenderness, and mood changes. These side effects should subside a few days after taking Provera.

Other side effects may include: 

• Change in menstrual bleeding or flow
• Acne
• Increase in weight
• Fatigue or sleep problems

It's important to note that Provera is contraindicated in pregnancy, so be sure to tell your physician if you think you may be pregnant. Sometimes your physician will require that you take either a blood or urine pregnancy test before taking this medication.

In addition, Provera by itself is not a reliable means of contraception, even though it is a hormone. If you are taking Provera, be sure to use a barrier contraceptive (for example, a condom) to prevent pregnancy.

Review all your medical problems and medications with your doctor before taking Provera. Besides pregnancy, there are other contraindications to taking Provera in addition to the side effects, especially if it is combined with an estrogen.

A Word From Verywell

The most common purpose of prescribing Provera is to help a doctor diagnose or treat menstrual cycle problems like abnormal bleeding or an absence of periods. It is also used to prevent uterine lining overgrowth in postmenopausal women who are also taking estrogen. It can be complex to understand why you are taking a particular hormone, like Provera. Be sure to bring up any questions or worries with your doctor.