Why am I still bleeding after my injection? Understanding Breakthrough Bleeding

September 28, 2025 •

4 min read

Irregular bleeding is a common side effect for many people starting hormonal injections like Depo-Provera, with some studies indicating it affects over half of users in the first year. If you find yourself asking, "Why am I still bleeding after my injection?" it's often a normal part of your body adjusting to the new hormones.

Quick Summary

Ongoing bleeding or spotting after a hormonal injection, such as the Depo-Provera birth control shot, is frequently due to your body adapting to the change in hormone levels and is most common during the first 6–12 months of use. The synthetic progestin can cause the uterine lining to shed irregularly as it thins out, leading to unpredictable bleeding patterns. In rare cases, other underlying conditions may be at fault, making it important to consult a doctor if bleeding is unusually heavy or persistent.

Key Points

Initial Hormonal Adjustment: For many, persistent bleeding after a hormonal injection like Depo-Provera is a normal side effect as the body adjusts to the new, stable hormone levels, especially within the first 6–12 months.
Breakthrough Bleeding Cause: The progestin in the shot thins the uterine lining, which can cause it to shed irregularly and unpredictably, leading to spotting or breakthrough bleeding.
Bleeding Patterns Evolve: Over time, most individuals find that the irregular bleeding lessens and may eventually stop completely, a common outcome for long-term users.
When to See a Doctor: Seek medical advice if you experience very heavy or prolonged bleeding, severe pain, or other concerning symptoms, as these could indicate underlying issues.
Management Options: In some cases, a doctor might suggest treatments like NSAIDs or a short course of estrogen to help manage heavy bleeding, or discuss alternative contraceptive options.
Other Factors at Play: Smoking, other medications, and underlying medical conditions can also contribute to or affect bleeding patterns while on hormonal birth control.

Understanding Hormonal Contraceptive Injections

Hormonal birth control injections, most notably Depo-Provera, work by releasing a dose of the synthetic hormone progestin (depot medroxyprogesterone acetate) into your system. This hormone prevents pregnancy primarily by stopping ovulation, but it also causes changes to the lining of the uterus and cervical mucus. These hormonal shifts are the main reason for the bleeding irregularities that many users experience.

The Science Behind Irregular Bleeding

The progestin in the injection suppresses your body's natural cycle of hormones, which normally causes the uterine lining to build up and then shed each month during a period. With the injection, estrogen levels are kept low and stable, which results in a fragile and atrophic (thin) endometrial lining. This thin lining can shed unpredictably, causing prolonged or intermittent bleeding and spotting, known as 'breakthrough bleeding'.

Timeline of Bleeding After a Shot

The bleeding pattern you experience after an injection is not a cause for panic and will likely evolve over time. Here is a typical timeline:

First 6 months: This is often the most irregular period. Spotting or light bleeding between expected periods is very common. Some individuals may even have longer or heavier periods during this phase. Your body is still acclimatizing to the new, consistent level of progestin.
After 6–12 months: Many people will notice their bleeding becoming more regular, lighter, and less frequent. The initial adjustment period begins to subside.
After 12+ months: A significant portion of users, often around 50% or more, will experience an absence of periods entirely (amenorrhea), which is a safe and common effect. For others, periods will become much lighter and shorter.

When to Contact a Healthcare Provider

While irregular bleeding is a common and expected side effect, certain symptoms warrant a call to your doctor. It is crucial to monitor your bleeding and any accompanying symptoms to rule out other medical issues.

Comparison of Normal vs. Concerning Bleeding


Feature	Normal (Expected) Bleeding	Concerning (Abnormal) Bleeding
Pattern	Spotting or light, irregular bleeding, especially in the first year.	Unusually heavy bleeding, such as soaking through a pad or tampon every 1–2 hours for more than two consecutive hours.
Duration	Can be prolonged initially, but should eventually decrease in frequency.	Periods lasting longer than one week, or continuous bleeding for more than two weeks.
Associated Symptoms	Typically mild to moderate, if any.	Accompanied by severe pain, fever, dizziness, or fainting.
Other Signs	Normal energy levels, no signs of anemia.	Signs of anemia (e.g., severe fatigue, shortness of breath), or pus/prolonged pain at injection site.
Reason for Concern	Body is adjusting to hormonal contraception.	Could indicate underlying medical issues like infection, uterine growths, or another condition unrelated to the injection.

Potential Causes Beyond Hormonal Adjustments

Although hormonal changes are the most likely culprit, other factors can cause or worsen irregular bleeding. It's important to have a full picture to determine the root cause, especially if the bleeding is heavy or prolonged.

Other possible causes include:

Incorrect Injection Technique: In rare cases, improper administration of an intramuscular injection can lead to issues. If the needle hits a blood vessel, it can cause prolonged bruising or bleeding at the site. Symptoms like severe pain, numbness, or tingling at the site are red flags.
Underlying Medical Conditions: Abnormal uterine bleeding can mask other problems. A healthcare provider will want to rule out issues such as sexually transmitted infections (STIs), uterine fibroids, or other gynecological conditions that can cause similar bleeding patterns.
Medication or Supplement Interactions: Certain medications or herbal supplements can interfere with hormonal birth control, potentially causing breakthrough bleeding. It's crucial to inform your doctor about everything you are taking.
Smoking: Tobacco use is linked to an increased risk of breakthrough bleeding while on hormonal contraception.

Treatment Options for Heavy or Prolonged Bleeding

If the irregular bleeding is particularly bothersome, your doctor may suggest some remedies:

NSAID Therapy: Taking nonsteroidal anti-inflammatory drugs like ibuprofen for a short period may help to reduce the inflammation and bleeding. Always consult a doctor for advice regarding medication.
Estrogen Therapy: In some cases, a healthcare provider might prescribe a short course of estrogen to help stabilize the uterine lining and stop heavy bleeding. This is not suitable for everyone and must be done under a doctor's supervision.
Acceptance and Adjustment: For many, the bleeding is a temporary inconvenience. Preparing with pads or other menstrual products and recognizing that the bleeding is a normal side effect can help manage the frustration.
Stopping the Injection: If side effects are severe and unmanageable, your doctor may recommend discontinuing the injection. It's important to remember the hormonal effects can last for three months or more after the last shot. Your doctor can discuss alternative birth control methods.

Conclusion

Bleeding after a hormonal injection like Depo-Provera is a very common side effect, especially during the initial months as your body adjusts to the consistent dose of progestin. This breakthrough bleeding or spotting is typically not dangerous and often improves or stops completely over time. However, paying close attention to the nature and severity of the bleeding is crucial. Unusually heavy or persistent bleeding, or any new or worsening symptoms, should prompt a conversation with a healthcare provider to ensure there are no underlying health issues. Being informed and in regular contact with your doctor is the best approach to managing this side effect.

For more information on birth control and its effects, you can visit the Planned Parenthood website at https://www.plannedparenthood.org/learn/birth-control.

Disclaimer: This information is for general knowledge and should not be taken as medical advice. Consult with a healthcare professional before starting any new supplement regimen.

Frequently Asked Questions

Yes, continuous or irregular bleeding, often called breakthrough bleeding, is a very common side effect, especially during the first 6 to 12 months after starting a hormonal birth control injection like Depo-Provera. Your body is adjusting to the new hormone levels.

The duration varies for everyone. For most, the bleeding and spotting will become lighter and less frequent over time. Many users see the irregularity decrease significantly after the first year, with many eventually experiencing no periods at all.

You should contact your doctor if the bleeding is excessively heavy (e.g., soaking through a pad or tampon hourly for more than two hours), lasts for more than two weeks, or is accompanied by severe pain, fever, or dizziness.

While lighter, irregular bleeding is normal, persistent and heavy bleeding could potentially lead to anemia over time. Your doctor can check your iron levels and suggest ways to manage the bleeding if this is a concern.

No, persistent or irregular bleeding does not mean the injection is ineffective. The medication is still actively preventing ovulation. The bleeding is a side effect of the hormonal changes, not an indication of contraceptive failure.

After stopping a long-acting injection like Depo-Provera, the hormones can remain in your system for several months. It is normal to experience irregular bleeding for a period as your natural cycle returns, which can take up to a year.

In some cases, a doctor may recommend short-term treatments like NSAIDs (ibuprofen) or hormonal therapy to help control heavy or prolonged bleeding. Lifestyle factors like quitting smoking may also help.