Birth control shots – what you need to know

Why do women choose to have the birth control injection?

In the US, about 2% of sexually active women who want to avoid getting pregnant use this method of contraception.

“One shot protects you against pregnancy for 8 to 13 weeks,” explains Dr Ann Nainan, family doctor and Healthily expert. “This means you only need 4 to 7 injections a year – so birth control shots can be convenient for busy women. You also don’t have to remember to take pills every day, which some people find difficult.”

How do birth control shots work?

Birth control injections contain a type of the hormone progestin. This prevents you from getting pregnant by:

• stopping your ovaries from releasing an egg (ovulation) – so an egg can’t be fertilized by sperm
• thickening the mucus around the neck of your womb (cervix) – so it’s difficult for sperm to get into your womb to fertilize an egg
• thinning the lining of your womb (endometrium) – so even if an egg does get fertilized, it can’t implant into your womb lining and start developing

What’s the difference between the Depo shot, Sayana Press and Noristerat?

“There are different brands of birth control shot,” says Dr Ann. “The Depo-Provera shot – often called the Depo shot – is the most common. Other brands are Sayana Press and Noristerat. They all work in the same way, but there are a few differences.”

These differences include:

• how long they last – Depo-Provera and Sayana Press last 13 weeks, while Noristerat lasts for 8 weeks
• where you get the shot – Depo-Provera and Noristerat are usually injected into your buttocks, but you can also have them in your upper arm. Sayana Press can be injected into your tummy or thigh
• who gives the shot – Depo-Provera and Noristerat are given by a doctor or nurse, but you can learn to inject Sayana Press yourself

Birth control shot effectiveness

“Birth control shot effectiveness is very high,” says Dr Ann. “But it’s very important to make sure you get your injections at the right time (usually about every 3 months).”

Here’s what you need to know:

• if you time your shots perfectly, it’s more than 99% effective at preventing pregnancy
• not everyone remembers to schedule their shots at the right time – so it’s about 94% to 96% effective with real-life use

How to get the best from your birth control injection

Here’s how you and your healthcare professional can work together to make sure your birth control shot is as effective as possible.

When to get your shot

• you can have your first shot at any time during your menstrual cycle, as long as you’re sure you’re not pregnant
• if you get your first shot within 5 days of the start of your period, you don’t need to use another type of birth control
• if you get your first shot more than 5 days after the start of your period, you’ll need to use another type of birth control (such as condoms – or avoid sex – for the next 7 days
• if you’re changing from the shot to another type of contraception, you can do this any time before when you’d normally get your next shot – but check with your doctor first

How to remember to get your shot

The effectiveness of the shot depends on you getting it at the right time, so try these tips to help make sure you don’t miss it:

• book all your appointments for the year at once – and set up reminders in advance, so you don’t miss them or have to pay a cancellation penalty
• sign up for any reminder services your healthcare provider offers – such as SMS, email or phone calls
• write your appointments on your calendar
• set alarm reminders on your phone
• ask your partner to remind you when you need your next shot – they could set phone reminders, too

What to do if you’re late getting your shot

“This depends on how late you are and what type of shot you’re using,” says Dr Ann. “Always talk to your doctor about which injection you’re using and how often you need to have it”.

With Depo-Provera and Sayana Press:

• you can get a follow-up shot as early as 10 weeks or as late as 14 weeks after your last shot
• if it’s more than 14 weeks since your last shot, you’ll need to use extra contraception – such as a condom – for the first week after getting your next shot
• if you’ve had sex without using another type of birth control more than 14 weeks after your last shot, you might need to use emergency contraception (such as the morning-after pill) and take a pregnancy test before getting your next shot – so talk to your doctor

With Noristerat:

• you can get a follow-up shot as early as 6 weeks or as late as 10 weeks after your last shot
• talk to your doctor if you’ve had sex without using another type of birth control more than 10 weeks after your last shot – you might need to use emergency contraception and take a pregnancy test before getting your next shot

How to come off the birth control shot

If you want to stop using the birth control shot, all you need to do is not get your next shot when it’s due.

Remember that if you don’t want to get pregnant, you should start using another type of contraception before your next shot is due – even if your period hasn’t come back yet.

Is the birth control shot right for me?

“Only you can decide what type of contraception best suits your lifestyle and preference,” says Dr Ann. “If you have a busy life and aren’t good at remembering to take a pill every day, the shot may be a good choice for you. But as with all types of contraception, it has advantages and disadvantages.

“You might also want to consider other long-term methods of birth control, such as the [implant], hormonal IUD or copper IUD. It can be helpful to talk about all the options with your doctor or a contraception nurse.”

What are the benefits and advantages of the birth control shot?

• each shot protects you for about 2 or 3 months – so you don’t have to think about birth control until it’s time for your next one
• it doesn’t interrupt sex – unlike putting on a condom, for example
• it can make your periods lighter or stop completely, and can also make them less painful
• it isn’t affected by any other medicines you may take
• it’s safe to have straight after giving birth, and when breastfeeding – though if you’re breastfeeding, you’ll usually need to wait 6 weeks from having your baby
• it’s thought that it may offer some protection against endometrial cancer and ovarian cancer
• if you have sickle cell disease, some research suggests it may help with sickle cell crisis pain (but discuss this with your doctor)
• if you have epilepsy, there’s some evidence that it may reduce seizures – but it’s important to discuss your contraception options with your doctor

What are the side effects of the birth control shot?

Most of the shot’s possible side effects aren’t common. The main thing you’re likely to notice is changes to your menstrual cycle. These can include:

• heavier periods, irregular periods or spotting
• shorter and lighter periods
• no periods – about 50% of women stop getting periods after a year of having the shot

It’s best to speak to your doctor about any changes to your period, including bleeding between periods or spotting. They can check what’s causing them, and advise on things to help.

If you stop having the shot, your periods will usually come back – although it might take a few months, and sometimes up to a year. Remember, though, that it’s still possible to get pregnant at this time, even if you’re not having periods. So always use another method of birth control if you stop having the shot and you don’t want to get pregnant.

Other potential side effects include:

• headaches, acne, hair loss, mood swings and decreased sex drive – these may continue for as long as your shot lasts, and for a few weeks afterwards
• weight gain – the shot may be associated with putting on weight. Studies have found that women gain an average of 5 to 8lbs in the first 1 to 2 years of having it. You may be more likely to put on weight if you’re under 18 and have a body mass index (BMI) over 30. Studies also show that if you gain more than 5% of your body weight in the first 6 months, you’re likely to continue to gain weight while using the shot
• bone thinning – your bones may thin slightly while using the birth control shot. There isn’t any strong evidence that this increases your risk of breaking a bone, and in most cases, some or all of the bone replaces itself once you stop having shots. If you’re under 18, the UK Faculty of Sexual & Reproductive Healthcare recommends you talk to your doctor before considering Depo birth control, as your bones are still growing. You should also speak to your doctor if you have any other risk factors for fractures, and reassess the risks every 2 years when using the shot
• infection or allergic reaction – there’s a small risk of getting an infection at the site of your shot, or having an allergic reaction to the shot. Skin reactions are more common with Sayana Press, with studies reporting a range of reactions happening in between 1.6% and 21% of cases. One study found that skin changes such as scarring happened in 1 in 10 people

From the limited evidence available, we can’t be sure if there’s a link between the shot and an increased risk of heart attack or stroke. Talk to your doctor if you have risk factors for heart disease (such as smoking, obesity or diabetes), as they may recommend a different type of contraception.

Other disadvantages include:

• it doesn’t protect against sexually transmitted infections (STIs) – if you want protection from STIs, you’ll need to use condoms as well
• it can take up to a year before your fertility returns to normal – so it might not be suitable if you want to get pregnant soon. However, evidence shows that about 6 out of 10 women get pregnant within 12 months of stopping using Depo shot birth control, and more than 8 out of 10 within 2 years

Who shouldn’t have birth control shots?

Your doctor may recommend you use another type of contraception if you:

• are pregnant, or think you might be pregnant
• have liver disease
• have breast cancer, or have had it in the past
• have unexplained bleeding after sex or between periods
• don’t want your periods to change
• want to have a baby in the next year
• are at risk of the fragile bone condition osteoporosis
• have a history of heart disease or stroke

Where to get the birth control shot

“Your ob-gyn or another healthcare professional will usually give you your injection,” says Dr Ann. “And if you want to learn how to inject Sayana Press, ask your healthcare professional.”

• in the US – most insurance plans cover FDA-approved birth control, but check your cover. If you don’t have health insurance, check with your state’s Medicaid program to see what’s included
• in the UK – you can get the birth control injection for free from sexual health clinics, GP surgeries, contraception clinics and some young people's services. (This applies even if you’re under 16)

What if I don’t like getting shots?

We know you might not like getting shots – who does? In fact, about 10% of Americans are highly anxious about needles. But this shouldn’t mean the shot isn’t for you.

Simple tips to make getting a shot easier include:

• telling your doctor or nurse how your feel, so they can help put you at ease
• applying lidocaine cream to the injection site beforehand, to numb any discomfort
• not looking at the needle
• closing your eyes and thinking nice thoughts
• breathing deeply

And remember, if you really can’t face having a shot every few months, there are effective birth control options that don’t involve needles – check out other types of contraceptives.