Medroxyprogesterone

Key facts

• Medroxyprogesterone is a synthetic form of progesterone. As an injection, often called DMPA, it is a long-acting contraceptive; as a tablet it treats abnormal uterine bleeding and protects the uterine lining when combined with estrogen therapy.
• The contraceptive injection is given every 12 to 13 weeks; tablets are usually taken for a set number of days each cycle, or continuously as part of hormone therapy.
• Medroxyprogesterone increases the risk of blood clots in the legs and lungs, and the injectable form reduces bone mineral density with long-term use, an effect that partly reverses after stopping.
• Seek urgent care for pain and swelling in one leg, sudden breathlessness, or chest pain.

What medroxyprogesterone treats

Medroxyprogesterone treats abnormal uterine bleeding by thinning the uterine lining, and is used as the progestogen component of menopausal hormone therapy in women with a uterus, to prevent the endometrial overgrowth that estrogen alone can cause. The injectable form is a highly effective contraceptive. Higher doses are occasionally used to treat certain hormone-sensitive endometrial or kidney cancers, and to stimulate appetite in severe weight loss from illness. It is not used to treat osteoporosis, and long-term injectable use itself needs bone-density monitoring.

How medroxyprogesterone works

Medroxyprogesterone binds progesterone receptors, mimicking the hormone's natural effects: it thins the uterine lining, suppresses ovulation, and thickens cervical mucus. This combination prevents pregnancy at contraceptive doses and controls abnormal bleeding at treatment doses. Suppressing estrogen production over long periods is also why bone density can fall during extended injectable use.

Before you take it

• Do not use medroxyprogesterone if you have undiagnosed abnormal vaginal bleeding, active liver disease, a history of blood clots, or known or suspected breast cancer.
• Tell your prescriber about migraine with aura, depression, or risk factors for osteoporosis before starting the injectable form.
• Smoking increases clot risk when medroxyprogesterone is combined with estrogen.
• Return for each injection on schedule; delays can reduce contraceptive protection and may need a pregnancy check before the next dose.

Side effects

Common effects include irregular spotting, weight gain, headache, mood changes and, with the injection, a delay in the return of periods and fertility after stopping.

Stop and seek urgent medical care for any of these:

• Pain, swelling or warmth in one leg, or sudden chest pain or breathlessness.
• Sudden severe headache, vision changes or one-sided weakness.
• Heavy, prolonged, or unusual vaginal bleeding.

Safety essentials

• Medroxyprogesterone raises the risk of blood clots; stop it and seek urgent care for leg swelling, chest pain or breathlessness, and tell any prescriber or surgeon that you use it.
• With the contraceptive injection, bone mineral density can fall with use beyond two years; your prescriber reviews ongoing need periodically, particularly in adolescents and women with other osteoporosis risk factors.
• Report any unscheduled or heavy vaginal bleeding, since it needs assessment rather than being assumed to be a normal side effect.
• Buy medroxyprogesterone only from a licensed pharmacy.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.