What is the injection for heavy periods? A Guide to Medical Treatments

October 14, 2025 •

3 min read

Heavy menstrual bleeding affects more than 10 million American women annually, meaning about one in every five women experiences it. For those seeking relief, a key question is: what is the injection for heavy periods?

Quick Summary

This article examines injectable medications for treating heavy menstrual bleeding (menorrhagia). It covers the mechanisms, effectiveness, and side effects of common options like Depo-Provera and GnRH agonists, and compares them to other treatments.

Key Points

Primary Injection: The most common injection for heavy periods is the progestin-only contraceptive shot (medroxyprogesterone acetate), known by the brand name Depo-Provera.
How It Works: Depo-Provera thins the uterine lining, which can significantly reduce or even stop menstrual bleeding over time.
Other Injections: Gonadotropin-releasing hormone (GnRH) agonists, like leuprolide (Lupron), are another type of injection used to induce a temporary menopausal state, primarily for short-term treatment of fibroid-related bleeding before surgery.
Common Side Effects: Side effects of Depo-Provera include irregular bleeding (especially at first), weight gain, and with long-term use, a potential for reversible bone density loss.
Key Alternatives: Other effective treatments include the hormonal IUD (which reduces bleeding by up to 97%), non-hormonal tranexamic acid pills, and NSAIDs.
Diagnosis is Crucial: Heavy bleeding is defined by signs like soaking a pad/tampon hourly or bleeding for over 7 days; a proper diagnosis is needed to find the cause.
Consult a Doctor: Choosing the right treatment requires consulting a healthcare provider to discuss the cause, health history, and personal preferences.

Understanding Heavy Menstrual Bleeding (Menorrhagia)

Heavy menstrual bleeding, or menorrhagia, is defined as excessive menstrual blood loss that disrupts a person's physical, emotional, or social quality of life. ACOG defines heavy bleeding as soaking through one or more pads or tampons hourly for several hours, changing protection during the night, or passing large blood clots. This condition affects about one in five women and can lead to anemia, fatigue, and distress.

Causes include hormonal imbalances, fibroids, polyps, adenomyosis, and bleeding disorders. A healthcare provider can diagnose the cause with blood tests, ultrasound, or hysteroscopy.

The Primary Injection: Progestin-Only Contraceptives

The most common injection for heavy periods is the birth control shot containing progestin, often known as Depo-Provera.

How Depo-Provera (Medroxyprogesterone Acetate) Works

Depo-medroxyprogesterone acetate (DMPA) is a long-acting progestin given every 12-14 weeks. It prevents ovulation and thins the uterine lining. A thinner lining means less bleeding during a period. Many users experience lighter bleeding or stop having periods (amenorrhea) with continued use, often after about a year.

Efficacy and Side Effects

Depo-Provera effectively reduces menstrual blood loss. However, side effects can occur, including irregular bleeding and spotting, especially in the first year. Other side effects include weight gain, headaches, dizziness, and decreased sex drive.

Long-term DMPA use may reduce bone mineral density, which is generally reversible after stopping the medication. The FDA advises against using it for over two years unless other birth control methods are unsuitable.

Other Injectable Options: GnRH Agonists

GnRH agonists are another type of injection used for heavy periods, particularly when linked to conditions like uterine fibroids.

How GnRH Agonists (e.g., Leuprolide) Work

GnRH agonists like leuprolide (Lupron) suppress the release of hormones that stimulate estrogen production, creating a temporary, reversible, menopausal-like state. This stops the menstrual cycle and can shrink fibroids. They are highly effective at inducing amenorrhea.

They are often used short-term (3-6 months) to manage conditions like anemia from fibroid bleeding before surgery. An initial flare-up of symptoms may occur before hormone levels drop.

Side Effects and Considerations

Due to the menopausal-like state, side effects such as hot flashes, vaginal dryness, and bone density loss are common. Add-back therapy (small doses of estrogen/progestin) can help manage these effects without restarting heavy bleeding. GnRH agonists are generally used for specific cases, like preoperative fibroid treatment, due to cost and side effects.

Comparison of Treatments for Heavy Periods

Injections are one option among several treatments for heavy periods.


Treatment	Mechanism of Action	Efficacy in Reducing Bleeding	Common Side Effects	Best For
Depo-Provera Injection	Thins uterine lining, inhibits ovulation	High; many achieve amenorrhea over time	Irregular bleeding (initially), weight gain, potential bone density loss	Individuals seeking long-acting contraception and bleeding reduction who can tolerate hormonal side effects.
GnRH Agonist Injection (e.g., Lupron)	Induces a temporary menopausal state, stopping the cycle	Very high; induces amenorrhea	Menopausal symptoms (hot flashes), bone loss	Short-term treatment, often before surgery for fibroids, to reduce bleeding and fibroid size.
Hormonal IUD (e.g., Mirena)	Releases progestin locally to thin uterine lining	Reduces blood loss by up to 97%	Irregular bleeding/spotting (initially), insertion discomfort	Long-term (up to 5+ years), highly effective bleeding control for those who are candidates for an IUD.
Tranexamic Acid (Oral)	Non-hormonal; helps blood to clot by preventing fibrinolysis	Reduces bleeding by 30-55%	Nausea, diarrhea, headaches	Non-hormonal treatment taken only during the period for those who wish to avoid hormones or preserve fertility.
NSAIDs (e.g., Ibuprofen)	Non-hormonal; reduces prostaglandin levels	Reduces blood flow by 20-46%	Stomach upset	First-line, non-hormonal option for mild-to-moderate relief of bleeding and cramps.

Conclusion

The main injection for heavy periods is the progestin-only contraceptive, Depo-Provera, which reduces bleeding by thinning the uterine lining. GnRH agonists like Lupron are another option, highly effective but used short-term for specific issues like fibroids due to significant side effects.

Treatment choice depends on the cause, health history, need for contraception, fertility plans, and tolerance for side effects. Other options include the highly effective hormonal IUD and non-hormonal tranexamic acid. Discussing options with a healthcare provider is crucial for the best treatment plan.

Authoritative Link: For more information from a leading medical authority, please see the ACOG FAQ on Heavy Menstrual Bleeding.

Frequently Asked Questions

Heavy menstrual bleeding is diagnosed based on symptoms like soaking through a pad or tampon every hour, periods lasting longer than 7 days, or passing large blood clots. A doctor may perform a physical exam, blood tests to check for anemia, and imaging tests like an ultrasound to identify underlying causes such as fibroids or polyps.

While Depo-Provera can be effective, it often causes irregular bleeding or spotting during the first year of use. Significant reduction in bleeding, or the cessation of periods (amenorrhea), becomes more common with continued use, with many users stopping their periods after about one year.

The most notable long-term risk of Depo-Provera is a potential loss of bone mineral density, which may increase the risk of osteoporosis. This effect is generally considered reversible after stopping the injections. The FDA advises that it should only be used for more than two years if other contraceptive methods are unsuitable.

Depo-Provera is a highly effective contraceptive, with over 99% efficacy when injections are received on schedule every 3 months. GnRH agonists like leuprolide may not universally suppress ovulation and should not be considered a reliable contraceptive method on their own.

Depo-Provera does not cause permanent infertility, but there can be a delay in the return to fertility after stopping the injections. It can take an average of 12-18 months to become pregnant after the last shot.

Currently, the primary injectable treatments for heavy periods, such as Depo-Provera and GnRH agonists, are hormonal. Non-hormonal treatments are available in other forms, such as oral tablets like tranexamic acid and NSAIDs.

If an injection like Depo-Provera doesn't control heavy bleeding or causes problematic irregular bleeding, a healthcare provider may suggest other options. These can include a hormonal IUD (which is highly effective), oral medications like tranexamic acid, or procedural options like endometrial ablation if childbearing is complete.