What is the progestogen-only pill?

The progestogen-only pill, also known as a POP or the mini pill, is a common form of contraception for women. The progestogen-only pill contains a synthetic version of the hormone progesterone and, unlike many other forms of hormonal contraception, it doesn’t contain any oestrogen.

In this article we’ll look at how the mini pill works, how to take it, who can take the POP and potential side effects.  

How does the progestogen-only pill work?

The mini pill works by making it tougher for sperm to enter the womb and fertilise an egg. All progesterone-only pills thicken the mucus from your cervix, this makes it hard for sperm to move through. They also make the lining of your womb thinner, which makes it harder for a fertilised egg to implant. 
Some types of progestogen-only pill which contain desogestrel also prevent ovulation. Cerazette, Cerelle and Desogestrel are all examples of these.  

How effective is the progesterone-only pill?

If the mini pill is always used perfectly, it’s more than 99% effective. If the pill isn’t always taken using according to the instructions, it’s around 91% effective. 

How to take the progestogen-only pill

1. Take the mini pill advised by your clinician
2. Always keep your pack in a visible and memorable location
3. Take it at exactly the same time every day

Progestogen-only pill brands

Cerazette

Cerazette is one of the most popular progestogen-only pills. It provides a 12-hour window in which you can take it and still be protected from pregnancy.

Cerelle

Cerelle is another version of Cerazette which contains the same active ingredients and also has a 12-hour window.

Desogestrel

Desogestrel is a generic version of Cerazette and Cerelle, it contains the same active ingredients and works in the same way. 

Noriday

Noriday contains progestogen in the form of norethisterone and must be taken within the same three-hour window each day.

Norgeston

Norgeston contains progestogen in the form of levonorgestrel and must be taken within the same three-hour window each day. It is one of the cheapest POPs available.

What’s the difference between the combined pill and the mini pill? 

The main difference between the combined and the mini pill, is that the combined pill contains two hormones (oestrogen and progestogen) and the mini pill just has progestogen.  

Combined pills work in a similar way to progesterone-only pills, thickening the mucus in the cervix and thinning the lining of the womb. But also, all combined pills stop you from ovulating, which only desogestrel mini pills do.  

Most side-effects are similar to the mini pill, but for some women the combined pill can cause more serious problems. This means that the combined pill is not safe for everyone to use. However, many women like the more regular, shorter, and less painful periods about the combined pill.   

Can all women use the progestogen-only pill?

The mini pill is safe to take for the vast majority of women. It can be taken until the menopause or until you are 55 years old. 

It’s advised that you don’t take it if:

• There’s a possibility you’re pregnant already
• You're taking medication or supplements that make the pill less effective
• You're taking certain medication, for example certain anti-epileptics - this is because the mini pill can stop them from working
• You have or have had serious liver disease or breast cancer; or a heart attack or stroke that's been caused by a progestogen

When can I start taking the progesterone-only pill? 

You can start any time in your menstrual cycle, and if you begin from the first to the fifth day you will be covered immediately.  

A consultation with a clinician is usually required prior to taking any form of contraceptive pill. 

Benefits of the progestogen-only pill

• 99% effective if taken correctly
• Can be taken by women who have high blood pressure, are overweight, have a history of blood clots or experience migraines with aura
• Safe to take if you are over 35 and smoke
• Safe for most women up to the age of 55
• Can be taken whilst breastfeeding
• Periods may become lighter, or even stop altogether

Disadvantages of the progestogen-only pill

• Must be taken the same time every day. Cerazette and Cerelle, have a 12-hour window and other mini pills have a three-hour window.
• Does not protect against STIs
• Your periods may change in a way that does not suit you. They may become irregular, light, more frequent, last longer or stop altogether.

Side effects of the mini pill 

Like all medicines, there is a chance you’ll experience side effects if you take the mini pill.  

Common side effects of the progesterone-only pill include: 

• Acne 
• Sore breasts 
• Breasts getting bigger 
• Mood swings 
• Headaches 
• Nausea 
• Small ovarian cysts – these are harmless and disappear without the need for treatment.  

Bleeding on the mini pill

The mini pill is likely to affect your periods. Your might find that bleeding is irregular, lighter, more frequent, last longer or completely stop – everyone is different!
These changes are likely to settle after the first few months of taking the pill, but if there’s anything you’re not sure on it might be worth speaking to a clinician. Sometimes changing to a different mini pill might help. 

What do I do if I don’t take the mini pill on time?

If you forget to take it on time (within three hours for Norgeston and Noriday and 12 hours for Cerazette and Cerelle), you should:

• Take the missed pill as soon as you remember and then your next pill at the normal time. 
• You should only take one, even if you have missed more than one. 

You will not be covered for the next two days, so use barrier methods such as condoms, the cap or a diaphragm with spermicide over that time. If you've had unprotected sex within this two-day period, you may need emergency contraception.

Can you get pregnant after stopping taking the progestogen-only pill?

In the past clinicians advised waiting a month before trying to get pregannt, but you don't have to wait for your body to "clear" the hormones. It only takes a few days and they're not actually harmful to a pregnancy. 

The reason for the old advice to wait one month, is that  once you've had a natural period it's easier to work out your dates. It also gives you time to focus on a healthy lifestyle: stopping smoking, eating natural, home cooked foods and starting to take folic acid.

If you’re unsure if the mini pill is right for you, discover the other options available in our guide to different forms of contraception, or have a consultation with your GP, a nurse or pharmacist to discuss what would be best for you and your needs.

References

https://www.nhs.uk/conditions/contraception/the-pill-progestogen-only/