Important Safety Information for Injectable Birth Control

Injectable birth control is a contraceptive method given by injection on a schedule. Different injectable methods contain different hormones and have different safety considerations.

Injectable birth control may include:

  • Progestin-only injections, such as medroxyprogesterone acetate/DMPA-type injections
  • Monthly combined injections, which contain estrogen and progestin

Your doctor will review your health history before recommending or approving injectable birth control.

What injectable birth control is used for

Injectable birth control may be used to prevent pregnancy. Some injectable contraceptives may also affect menstrual bleeding patterns, cramps, or cycle symptoms.

Injectables must be given on schedule to maintain contraceptive protection.

Types of injectable birth control

Progestin-only injectable birth control

DMPA-type injections contain a progestin and do not contain estrogen. FDA labeling for Depo-Provera CI includes a boxed warning that women using Depo-Provera Contraceptive Injection may lose significant bone mineral density, and bone loss increases with longer duration of use and may not be completely reversible.

Monthly combined injectable birth control

Monthly combined injectables contain estrogen and progestin. Because they contain estrogen, they may not be appropriate for patients who have the same risk factors that make estrogen-containing birth control unsafe, such as smoking over age 35, certain blood clot risks, migraine with aura, uncontrolled high blood pressure, or certain cardiovascular conditions. CDC and WHO classify combined hormonal contraceptives separately from progestin-only methods because their safety profiles differ by condition.

Who should not use injectable birth control

You may not be eligible for injectable birth control if you:

  • Are pregnant or think you may be pregnant
  • Have unexplained vaginal bleeding
  • Have current or past breast cancer
  • Have severe liver disease or liver tumors
  • Are allergic to any ingredient in the injection

For DMPA-type injections, tell your doctor if you have osteoporosis, bone health concerns, eating disorders, long-term steroid use, or other risk factors for low bone mineral density.

For monthly combined injectables, also tell your doctor if you:

  • Smoke and are 35 years old or older
  • Have migraine with aura
  • Have high blood pressure
  • Have a history of blood clots, stroke, heart attack, or heart disease
  • Recently gave birth or are breastfeeding
  • Have diabetes with vascular complications
  • Have known clotting disorders

How injectable birth control is used

Injectable birth control must be administered according to the correct schedule for the specific product.

General reminders:

  • Do not delay scheduled injections.
  • Keep track of your next injection date.
  • Ask your doctor what to do if you are late.
  • Do not assume you are protected if your injection is overdue.
  • A pregnancy test or backup contraception may be needed if you are late.

Late injection guide

If you are late for your injection, your chance of pregnancy may increase.

A doctor may advise:

  • Pregnancy testing
  • Backup contraception
  • Emergency contraception, if appropriate
  • Rescheduling the injection
  • Switching to another method if injections are hard to maintain

The correct action depends on the injection type, how late the dose is, and whether you had unprotected sex.

Talk to a doctor before use

Before using injectable birth control, tell your doctor if you:

  • Recently gave birth or are breastfeeding
  • Have irregular or unexplained vaginal bleeding
  • Have breast cancer or a history of breast cancer
  • Have liver disease
  • Have risk factors for bone loss
  • Have high blood pressure, migraine with aura, smoking history, or clotting risks
  • Are taking medicines for seizures, tuberculosis, HIV, or herbal supplements

WHO guidance states that breastfeeding women less than 6 weeks postpartum can generally use progestogen-only injectables as MEC Category 2, meaning advantages generally outweigh theoretical or proven risks.

Special precautions

DMPA-type injections may cause:

  • Irregular bleeding
  • No monthly period
  • Weight changes
  • Delayed return to fertility after stopping
  • Changes in bone mineral density

Because FDA labeling for Depo-Provera CI includes a boxed warning on bone mineral density loss, discuss duration of use and bone health concerns with your doctor.

Monthly combined injectables contain estrogen and may have estrogen-related risks similar to other combined hormonal contraceptives.

Warning signs and emergency care

Seek emergency medical care immediately if you experience:

  • Chest pain or pressure
  • Sudden shortness of breath
  • Coughing blood
  • Severe headache that is new or unusual
  • Vision changes or vision loss
  • Weakness or numbness on one side of the body
  • Severe pain or swelling in one leg
  • Severe abdominal pain
  • Very heavy vaginal bleeding
  • Fainting
  • Severe allergic reaction symptoms, such as swelling of the face, lips, tongue, or throat

Do not wait for an online consultation if you have emergency symptoms.

Common side effects

Common side effects may include:

  • Irregular bleeding or spotting
  • No monthly period
  • Headache
  • Breast tenderness
  • Mood changes
  • Weight changes
  • Acne changes
  • Injection site pain or discomfort

Contact a doctor if side effects are severe, persistent, or concerning.

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This page is for general educational purposes only and does not replace medical advice, diagnosis, or treatment.