In this section
Make an Appointment
- Parents Home
- Allergy Center
- Asthma Center
- Cancer Center
- Diabetes Center
- A to Z
- Emotions & Behavior
- First Aid & Safety
- Food Allergy Center
- General Health
- Growth & Development
- Flu Center
- Heart Health
- Helping With Homework
- Diseases & Conditions
- Nutrition & Fitness Center
- Play & Learn Center
- School & Family Life
- Pregnancy & Newborn Center
- Sports Medicine Center
- Doctors & Hospitals
- Para Padres
- Kids Home
- Asthma Center for Kids
- Cancer Center for Kids
- Movies & More
- Diabetes Center for Kids
- Getting Help
- Puberty & Growing Up
- Health Problems of Grown-Ups
- Health Problems
- Homework Center
- How the Body Works
- Illnesses & Injuries
- Nutrition & Fitness Center for Kids
- Recipes & Cooking for Kids
- Staying Healthy
- Stay Safe Center
- Relax & Unwind Center
- Q&A for Kids
- The Heart
- Videos for Kids
- Staying Safe
- Kids' Medical Dictionary
- Para Niños
- Teens Home
- Asthma Center for Teens
- Be Your Best Self
- Cancer Center for Teens
- Diabetes Center for Teens
- Diseases & Conditions (for Teens)
- Drugs & Alcohol
- Expert Answers (Q&A)
- Flu Center for Teens
- Homework Help for Teens
- Infections (for Teens)
- Managing Your Medical Care
- Managing Your Weight
- Nutrition & Fitness Center for Teens
- Recipes for Teens
- Safety & First Aid
- School & Work
- Sexual Health
- Sports Center
- Stress & Coping Center
- Videos for Teens
- Para Adolescentes
The Birth Control Shot
What Is the Birth Control Shot?
The birth control shot is an injection given every 3 months to help prevent pregnancy. The birth control shot contains a longer acting form of the hormone progestin.
How Does the Birth Control Shot Work?
The hormone progestin in the birth control shot works by preventing ovulation (the release of an egg from the ovaries during the monthly menstrual cycle). If an egg isn't released, pregnancy can't happen because there's no egg for the sperm to fertilize.
The progestin also thickens the mucus around the cervix. This makes it hard for sperm to enter the uterus and reach any eggs that may have been released. The progestin also thins the lining of the uterus so that an egg will have a hard time attaching to the wall of the uterus.
How Well Does the Birth Control Shot Work to Prevent Pregnancy?
The birth control shot is an effective birth control method. Over the course of a year, about 6 out of 100 typical couples who use the birth control shot will have an accidental pregnancy. The chance of getting pregnant increases if someone waits longer than 3 months to get her next shot.
In general, how well each type of birth control method works depends on a lot of things. These include whether a person has any health conditions or is taking any medicines that might affect its use. It also depends on whether the method is convenient and whether they remember to use it correctly all the time.
Does the Birth Control Shot Help Prevent STDs?
Are There Any Side Effects With the Birth Control Shot?
Most users of the birth control shot will notice a change in their periods. Side effects can include:
- irregular periods or no menstrual periods
- weight gain, headaches, and breast tenderness
The U.S. Food and Drug Administration (FDA) has issued a safety warning about the use of the birth control shot. Studies link this shot to a loss of bone density, although bone density may recover when someone stops getting the shot. The loss of bone density seems to be worse when the shot is used for longer periods of time.
Doctors are not sure how this type of shot may affect the bone density of young people in the future, though. Anyone considering the shot should talk to their doctors about it and make sure that they get enough calcium each day. Those who smoke should be sure to let their doctors know because smoking may be connected to this bone density loss.
Some people receiving shots may notice their periods are irregular for up to a year after stopping the shot. But the shot does not cause permanent loss of fertility and most users can get pregnant after they stop getting the shot.
Who Can Use the Birth Control Shot?
Anyone who has trouble remembering to take birth control pills and who wants extremely good protection against pregnancy may want to use the birth control shot. Also, nursing mothers can use the birth control shot.
Some medical conditions make the use of the shot less effective or riskier. For example, it is not recommended anyone who has had blood clots, some types of cancers, or liver disease. Those who have had unexplained vaginal bleeding (bleeding that is not during their periods) or who might be pregnant should not get the birth control shot and should talk to their doctors.
Where Is the Birth Control Shot Available?
The shot must be prescribed and is given every 3 months in a doctor's office or family planning clinic.
How Much Does the Birth Control Shot Cost?
Each injection (3 months' worth of birth control) costs between $0 and about $150. Many health insurance plans cover the cost of birth control shots, as well as the cost of the doctor's visit. Family planning clinics (such as Planned Parenthood) may charge less.
When Should I Call the Doctor?
Someone getting the birth control shot should call the doctor if they:
- might be pregnant
- have a change in the smell or color of vaginal discharge
- have unexplained fever or chills
- have belly or pelvic pain
- have pain during sex
- have heavy or long-lasting vaginal bleeding
- have yellowing of the skin or eyes
- have severe headaches
- feel depressed
- have signs of a blood clot, such as lower leg pain, chest pain, trouble breathing, weakness, tingling, trouble speaking, or vision problems
- Answering Questions About Sex
- About Birth Control: What Parents Need to Know
- Your Daughter's First Gynecology Visit
- Should Girls Who Aren't Sexually Active Be Vaccinated Against HPV?
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
© 1995- KidsHealth® All rights reserved.
Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.