What is the contraceptive injection?

The contraceptive injection is a long-acting, reversible method of birth control that can provide up to 13 weeks of protection against pregnancy per injection.

Each injection contains a synthetic form of progesterone, usually medroxyprogesterone acetate or norethisterone, which works to stop you getting pregnant. The contraceptive injection does not contain oestrogen.

The contraceptive injection is usually given by a qualified healthcare professional, like a doctor or a nurse. You can inject one type called Sayana Press at home after you have been shown how by a doctor or nurse. You will need to make an appointment with your doctor, so they can assess if the contraceptive injection is right for you and help you decide which type is most suitable.

The contraceptive injection is a progesterone-only contraceptive which works by stopping your ovaries from releasing an egg, also known as ovulation. It works similarly to the mini pill, except it is injected subcutaneously. That means it is injected into the fatty tissue just below your skin.

The contraceptive pill can work in 3 ways to prevent pregnancy. It:

1. Stops your ovaries from releasing an egg (ovulation).
2. Thins the lining of the womb to make it difficult for a fertilised egg to attach and grow.
3. Thickens the cervical mucus, making it more difficult for sperm to reach an egg and fertilise it.

How long does the contraceptive injection last?

Depending on the type of injection you are using, you will need to have a new injection every 8 to 13 weeks. If you use Depo-Provera, it lasts 12 weeks (though it can be given up to 5 days after this). Sayana Press lasts for 13 weeks. Another type of contraceptive injection, Noristerat, is effective for 8 weeks.

How long does the contraceptive injection take to work?

If you get your first contraceptive injection in the first 5 days of your period, you will be protected from pregnancy straight away.

If you get your first contraceptive injection after day 5, you will not receive immediate protection. You will need to use an additional contraception method, like condoms, for 7 days after getting your injection.

How effective is the contraceptive injection?

If used correctly, the contraceptive injection is more than 99% effective at preventing pregnancy. If you get the injection late, the effectiveness drops to 94%, meaning 6 in 100 people will get pregnant in 1 year while using it.

Compared to progesterone-only pills, the contraceptive injection is slightly more effective when it is used typically. For example, when both types of birth control are used perfectly, they are both more than 99% effective. However, with typical use, which includes things like missing a pill or getting your injection late, the mini pill is 91% effective, whereas the injection remains 94% effective.

How often do I need to get the injection?

How often you will need to get the contraceptive injection depends on which type you are given. If you use Depo-Provera, you’ll need a new injection every 12 weeks. Sayana Press needs injected every 13 weeks. Noristerat injections are given every 8 weeks.

The contraceptive injection is a subcutaneous injection, which means it’s injected into the fatty tissue just below the skin. Where it’s injected will depend on which type of injection you are given:

• Depo-Provera and Noristerat are injected in your bottom, but can sometimes be given in your upper arm
• Sayana Press is injected into your lower tummy or the front of your thigh because it’s self-injected

There are 3 main types of contraceptive injections available. They are all long-acting, reversible contraceptives (LARCs) that contain progesterone to prevent pregnancy.

Here are some of the similarities and differences of the contraceptive injections available in the UK:

You can get the contraceptive injection for free on the NHS. It’s available from:

• sexual health clinics, also known as family planning or contraception clinics
• GP surgeries
• some young people’s services

The contraceptive injection can cause side effects, although not everyone will get them. It is important to be aware of them so you know what to look out for, or to help you choose the right birth control method for you.

As each injection contains either a different active ingredient or the same ingredient in a different dose, the side effects can vary slightly, such as how often they happen.

Common side effects of contraceptive injections include:

• period changes, such as them becoming irregular, lasting longer, or stopping completely (the longer you use it, the more likely your periods will stop)
• weight gain
• injection site reactions, such as pain, or a small lump or a scar (you or the healthcare professional injecting should use a slightly different area of skin each time to reduce this risk)

Other reported side effects include acne, reduced sex drive, changes in mood, hot flushes, and headache.

There are also some long-term side effects associated with the contraceptive injection. For example, medroxyprogesterone (Depo-Provera and Sayana Press) can cause weak and fragile bones if you use it for a long time. However, you can lower this risk by exercising regularly and making sure you get enough calcium in your diet.

Medroxyprogesterone injections also increase the risk of a specific type of brain tumour called meningioma if you take them for 3 years or more. However, this type of brain tumour is rare, so the risk is small.

How long do contraceptive injection side effects last?

Contraceptive injection side effects can last for several months because of how long the active ingredient remains in your system. Long-term side effects may last longer, but are rare. You should speak to your doctor about any side effects so they can monitor them.

What to do if you get the contraceptive injection side effects

Most mild contraceptive injection side effects can be managed at home in the following ways:

• headaches – get plenty of rest, drink clear fluids, and speak to a pharmacist about over-the-counter painkillers
• stomach pain and bloating – eat and drink slowly, choose smaller, more frequent meal, or hold a heat pad or a covered hot water bottle on your stomach
• feeling sick – get some rest, avoid rich or spicy foods, and sip clear fluids
• weight changes – eat a healthy, balanced diet and get regular exercise to help keep your weight within a healthy range
• dizziness – stop what you are doing, sit or lie down until you feel better, and avoid driving, operating machinery, or cycling until you feel better
• itchy skin – taking an antihistamine may help, speak to a pharmacist to find a suitable type

If you experience any side effects that you feel are lasting for too long or are difficult to manage, speak to your doctor for advice.

If you experience any of the following serious side effects, call 999 or get someone to take you to A&E:

• sudden skin rash
• swelling face, lips, tongue, or throat
• wheezing
• difficulty breathing
• blood clot in the lungs, symptoms include shortness of breath, breath-related chest pains, and coughing up blood
• blood clot in the leg, symptoms include pain, tenderness, or swelling in the calf, painful or inflamed veins in your leg, difficulty putting weight on the affected leg, and purple discolouration or redness and warmth
• jaundice

The contraceptive injection may not be right for everyone. A doctor or nurse will ask about your medical history before giving you the injection. They may not recommend it if you:

• have ever had breast cancer, heart disease, or stroke
• have ever had a liver condition
• have ever had unexplained bleeding
• smoke
• have diabetes
• have high blood pressure
• have high cholesterol
• are obese
• have a history of a specific type of brain tumour called a meningioma
• are or think you might be pregnant

Meningioma

Contraceptive injections that contain medroxyprogesterone acetate, like Depo-Provera and Sayana Press, are associated with the development of a specific type of benign brain tumour called a meningioma. This risk increases the longer you use the contraceptive injection. If you notice any of the following symptoms, you should let your doctor know straight away:

• vision changes
• hearing loss or ringing in the ears
• loss of smell
• headaches that get worse over time
• memory loss
• seizures
• weakness in your arms or legs

Psychiatric disorders

Some people have reported depression or a depressed mood after using the contraceptive injection. If this is affecting you and you need help, speak to your doctor or a mental health practitioner. If you feel severely depressed, call 111 or 999 in an emergency.

Changes to your period

The contraceptive injection can disrupt the pattern of your periods. After your first injection, you may notice that you have irregular or longer-lasting bleeding or spotting. This is normal and not usually something to worry about.

Around one-third of people may have no bleeding at all. However, once you stop using the contraceptive injection, your periods should return within a few months. If they do not, or you have very heavy or prolonged periods, you should speak to your doctor.

Bone health

The contraceptive injection works by lowering some of your hormone levels, including oestrogen, which can cause your bones to become thinner. For example, women who use the contraceptive injection usually have a lower bone mineral density than women of the same age who have never used it.

If you’re under 18 and are considering the contraceptive injection as a method of birth control, your doctor or nurse will discuss whether it is right for you. During your teenage years, your bones are growing and strengthening quickly, but because injections like Depo-Provera and Sayana Press may weaken your bones when they should be growing, it may not be the most suitable birth control method.

You should let the doctor or nurse know about any prescribed, over-the-counter, or herbal medications you are taking or plan to take when you have the contraceptive injection. That’s because some medications can interact with each other and impact their effectiveness or cause side effects.

Although the contraceptive injection offers several advantages, it may not be the best option for everyone. There are many different types of contraception available that can suit your needs and preferences.

Progesterone-only pill

Also known as the mini pill, the progesterone-only pill works similarly to the contraceptive injection because it only contains 1 hormone, a man-made version of progesterone.

When taken correctly, the mini pill is more than 99% effective. Because the mini pill does not contain oestrogen, there’s less risk of oestrogen-related side effects than with a combined contraceptive pill.

The mini pill must be taken at the same time every day, usually within a 3 or 12-hour window, depending on which type you are prescribed. You can request the mini pill from ZAVA and can choose from some of the following examples:

• Cerelle
• Cerazette
• Zelleta
• Norgeston
• Noriday

Hana is a type of mini pill that is available over-the-counter without a prescription from most UK pharmacies and reputable online doctor services.

Combined contraceptive pill

The combined pill contains 2 synthetic sex hormones, oestrogen and progesterone. It works similarly to the mini pill in that it prevents ovulation, thicken cervical mucus, and thin the womb lining and is more than 99% effective when taken perfectly.

The combined pill is usually taken every day for 21 days, and then you have a 7-day break. During this time, you should experience a withdrawal bleed, like a period. However, some pills are taken every day without a break.

There are many different contraceptive pill brands, but some of the popular combined pills we offer include:

• Microgynon
• Yasmin
• Rigevidon
• Marvelon
• Gedarel

Contraceptive patches

An alternative to the combined oral contraceptive pill is contraceptive patches like Evra. These contain both oestrogen and progesterone and work in the same way as the combined pill to prevent pregnancy. However, you apply a new patch every week for 3 weeks and then have a 7-day break before applying a new patch.

Evra patches may be suitable for you if you struggle to remember to take a pill every day or find taking tablets difficult. Like the pill, when the contraceptive patch is used perfectly, it is 99% effective.

Other types of contraception

Several other contraceptive options are available, including non-hormonal birth control, such as:

• condoms
• diaphragms
• copper intrauterine device (IUD)
• cervical cap
• spermicide
• birth control sponge

Several other hormonal contraceptives are available, like the:

• contraceptive implant – a long-term method of contraception that is placed under the skin in your upper arm and slowly releases progesterone for up to 3 years
• hormonal coil – similar to the copper coil, it’s inserted into the womb by a doctor or nurse, but releases progesterone and can remain effective for 3 to 5 years