Your guide to hormonal contraception

How does hormonal contraception work?

Your menstrual cycle is a series of changes to hormone production and reproductive system which is your body’s way of preparing for pregnancy. There are two reproductive hormones that regulate the process:

• oestrogen - triggers ovulation, the process in which an egg is released from the ovary and into the fallopian tube
• progesterone - reduces the cervical mucus to allow for sperm to more easily reach the egg and thickens the lining of the uterus so an egg can easily implant itself

The levels of these hormones naturally fluctuate at different points in your cycle to trigger these processes to prepare for pregnancy.

Hormonal contraception works by keeping the levels of these hormones stable, by supplementing synthetic versions of these hormones. By doing so, these processes aren’t triggered which prevents conception.

Some hormonal methods contain just a synthetic progesterone (progestin), meaning they predominantly affect the cervix and uterus linings. Others are combined contraceptives, which contain both a synthetic oestrogen and progesterone. That means they affect ovulation as well as the progesterone-governed processes.

Below are two simple graphs depicting hormone levels in your natural menstrual cycle compared to whilst using a combined hormonal contraception.

What are the benefits of using hormonal contraception?

Each type of hormonal contraceptive has its own set of advantages and disadvantages, but some shared benefits across all types include:

• they are over 95 - 99% effective when used correctly
• can reduce symptoms of premenstrual syndrome (PMS)
• are easy to change or reverse if you want to change contraception or become pregnant
• do not physically “interrupt” sex like barrier contraceptives do

Hormonal contraceptives do not protect you from sexually transmitted infections (STIs). Unprotected sex whilst using hormonal contraception could still lead to an STI and you should use barrier contraceptives to protect yourself.

Keep reading to learn about each type of hormonal contraception.

The combined pill

“The pill” is the common term for the combined oral contraceptive pill, one of the most well known and commonly prescribed hormonal contraceptives. It is also usually the first type of birth control your doctor prescribes.

Doses differ depending on the type of pill you use. Monophasic pills (e.g Microgynon and Yasmin) contain the same dose across each hormonal pill. Multiphasic pills (e.g Logynon and Qlaira) will contain two or more doses across the pills for different stages in your cycle.

How do you take the combined pill?

You take just one pill once per day. There are two main ways you can take it.

The first are the 21-day pills. You take one pill each day for 21 days and then take a 7 day pill-free break to allow for a withdrawal bleed.

The second type are the everyday or 28-day pills. Each strip in the pack will contain a set of hormonal pills and a set of inactive pills that contain no hormones. Most commonly, a 28-day pill will contain 21 hormonal pills and 7 inactive pills. However, some other brands (like Zoely) contain 24 hormonal pills and 4 inactive pills. Both types work the same. You start by taking the hormonal tablets each day, but instead of taking a break, you take the inactive pills to allow for a withdrawal bleed. These pills will usually have “ED” in the name (e.g Microgynon ED).

While the pill is designed to have a break, you can choose not to have a bleed and take the hormonal pills back to back if you want to skip your period.

What’s important about the combined pill is that you take each pill at the same time each day. Taking it more than 12 hours late could alter your contraception.

Advantages and disadvantages

The mini-pill

The “mini-pill” is the common name for the progestogen-only pill or POP. Whilst it can be confused with the combined pill, it is different in that it only contains one synthetic hormone as opposed to two. It is a great oral contraceptive for those who cannot take oestrogen.

Mini-pills that contain the synthetic progesterone desogestrel (e.g Cerazette or Cerelle) can also prevent ovulation but the effect is not so consistent.

How do I take the mini-pill?

There are 28 pills in each strip in your pack. You do not take a break between strips, they must be taken back-to-back for it to be effective.

Like the combined pill, the mini-pill must be taken at the same time each day. How late you can take it depends on your mini-pill.

The “traditional” type of mini-pill containing progestins such as levonorgestrel (e.g Norgeston) or norethisterone (e.g Noriday) cannot be taken any later than 3 hours. Desogestrel pills, on the other hand, can be taken up to 12 hours late.

Advantages and disadvantages

Contraceptive patch

The first on our list which isn't a birth control pill is the contraceptive patch. It’s a transdermal patch that contains both oestrogen and progesterone. For many, it’s a low maintenance alternative to the combined pill. The only hormonal patch available in the UK is Evra.

How to use the contraceptive patch

The patch needs to be applied and changed once a week. You wear your first patch for 7 days, and apply a new patch on the 8th day. After 3 weeks of changing your patch once a week, you then have a patch-free week.

It can be placed to dry, hairless and clean skin on your abdomen, buttocks, shoulder or upper arm. It’s recommended you change where you put the patch each week to prevent any skin irritation.

Advantages and disadvantages

Vaginal ring

The NuvaRing is a small, flexible device that you insert into the vagina. It is a combined contraceptive, and therefore releases both synthetic oestrogen and progesterone into the bloodstream to prevent pregnancy.

How to use a NuvaRing

The device only needs to be inserted once every 3 weeks. Then, you have a 7 day break without a ring inserted to have a withdrawal bleed. The ring is also easy to insert and remove, and doesn’t cause any discomfort. You can also have sex or use tampons whilst you have the ring inserted.

Advantages and disadvantages

Intrauterine system (IUS)

The hormonal IUD, more commonly known as the intrauterine system (IUS) in the UK, is a small t-shaped device that is inserted into the uterus by a doctor or nurse. It is one of the most effective forms of contraception available.

It is different to the “copper coil” or copper IUD (intrauterine device) as instead of copper, it releases a synthetic progesterone into the womb. It is also unlike the coil in that it cannot be used as a form of emergency contraception.

The IUS can be left in for 3 - 5 years without being changed, however you will still need to regularly check that it’s in place.

Advantages and disadvantages

The contraceptive implant

The birth control implant is a small, flexible plastic rod. It is inserted under the skin in your upper arm by a healthcare professional and releases the hormone progestogen into your bloodstream. Once inserted, it can be left in for 3 years but can be taken out at any time before then.

Advantages and disadvantages

The contraceptive injection

Another hormonal contraceptive option available is the injection. It is injected into the buttock, thigh or upper arm and releases progestogen into the bloodstream. There are a few types available on the NHS.

• Depo-Provera - most commonly offered, lasts for 13 weeks
• Noristerat - less common, lasts for 8 weeks
• Sayana Press - newer injection on the market, lasts for 13 weeks and is available online

Most types of injection will need to be administered by a healthcare professional however Sayana Press can be done yourself.

Advantages and disadvantages

How do I pick my method of contraception?

As you can see, there is no shortage of hormonal contraceptives available. That can make it difficult to decide the best option for you. It’s important to assess your own lifestyle and how each option will work for you. For instance, if you have a busy lifestyle or you’re forgetful, relying on taking a pill every day may not be the best solution for you.

Hormonal contraception isn’t the only method available either. There are many different methods that are natural, permanent (e.g vasectomy) or physical (e.g barrier methods like male or female condoms) that may be more suitable for you if you’re worried about side effects or long-term risk.

If you’re still not sure or overwhelmed by options, make an appointment with your doctor or head to a family planning clinic or sexual health clinic and they can help you figure out what’s best for you.