Cerelle is a progesterone-only contraceptive pill (mini-pill) which contains a single active ingredient, synthetic hormone desogestrel which is highly adept at mimicking the activity of naturally-occurring sex hormone progesterone. Cerelle POP (progesterone-only pill) is manufactured and marketed in the UK by Consilient pharmaceutical company. As it does not contain oestrogen bioequivalent, it is considered to be a safer alternative to combined birth control pills and as such, it is commonly prescribed to women who are especially sensitive to side effects caused by combined oral contraceptives. In addition to this, POPs such as Cerelle can also be safely used by women who are currently breastfeeding.

What’s on this page?

How reliable is Cerelle?

Despite the often-mentioned claim that mini-pills are not as reliable as combined birth control as combined oral contraceptives are, this is not entirely true. While combined contraceptive pills really provide an additional layer of protection due to the presence of synthetic oestrogen, the presence of this additional active ingredient will provide defences which are considered to be inadequate on their own. More specifically, they involve the thickening of the vaginal fluid which makes it harder, but not impossible for the sperm to reach the egg cell.

When it comes to main mechanism of action, progesterone-only pills (POPs) and combined contraceptives are identical, but more on that below.

So, Cerelle is considered to be highly efficient and able to prevent unwanted pregnancy in as much as 99% of cases. However, in order to keep the efficiency on these high levels, you must ensure that you are taking Cerelle properly, exactly as prescribed by your doctor and in line with the official information that you can find in the official patient information leaflet. As long as you do everything properly, Cerelle should protect you from pregnancy very efficiently.

How Cerelle prevents pregnancy?

Just like other mini-pills available on the UK market, Cerelle too prevents pregnancy by mimicking the activity of naturally-occurring sex hormone progesterone once it is introduced into the female organism. Progesterone plays a crucial role in numerous processes that the female body goes through each month in order to prepare itself for potential pregnancy. Most important of these is ovulation, the release of the egg cell from the ovaries to the fallopian tube without which conception simply cannot take place. And this is exactly where Cerelle comes into play.

Thanks to desogestrel, synthetic progesterone which is the active ingredient of Cerelle, this birth control mini-pill will efficiently prevent ovulation, thus making pregnancy impossible. It does this thanks to the fact that this compound is highly adept at mimicking the activity of naturally-synthesised progesterone and because the body will not be able to detect it as a compound that is different from progesterone. The same is true for other POPs available on the UK market, like Nacrez, for example.

As a consequence, the presence of Cerelle in organism will trick the body into detecting higher levels of progesterone which will in turn make it “think” that the ovulation already took place and the egg cell won’t be released. This mechanism of action has been tested time and time again and is considered to be the most reliable method of preventing pregnancy, as long as you use your oral contraceptives properly.

Can I buy Cerelle online in the UK?

Birth control pills of any kind, including progesterone-only mini-pills such as Cerelle are prescription-only medications in the UK, but this is no obstacle to obtaining them without leaving the comfort of your home. In fact, today it is easier to get medication online than ever before.

So, if you are looking to buy Cerelle online in the UK, you should find an online clinic operating within the country. As you are trying to get a prescription medication, you will be required to fill in a detailed and specialised medical questionnaire that the doctor employed at the online clinic will use in order to get a better insight into your medical profile and history. Using this knowledge, it will be possible to make an informed assessment regarding your suitability for taking Cerelle.

If everything checks out, the doctor will issue the prescription and use it to have it sent from the partner pharmacy to the address you provided during the sign up process.

How to take Cerelle?

As was mentioned, taking Cerelle properly and in line with the official guidelines is absolutely crucial in ensuring optimal protection. This is not difficult or complicated, but will still require you to be careful and not to miss a pill. Below, we will provide you with some of the most general guidelines, but before that, we would like to note that the points below are there for illustrative purposes and can never be used as a substitute for the official information or the doctor’s advice.

  • Take Cerelle exactly as instructed and in line with the official guidelines
  • Take one Cerelle tablet each day
  • Unless you are switching from another birth control pill or have recently been pregnant, you should start taking Cerelle on the first day of your period
  • If this is not the case, consult the leaflet on how and when to commence treatment
  • Strips containing the tablets are marked by labels and arrows which will help you keep track of the treatment and make sure you haven’t missed any pills
  • Always take the tablets whole, never chew or break them
  • If you forget to take a pill, consult the leaflet on how to proceed

What are Cerelle side effects?

As is the case with all prescription-medications, Cerelle also comes with risk of causing some adverse effects in women who are susceptible to them and it is advised to get familiar with them prior to commencing treatment. You should be able to differentiate between those side effects which are uncomfortable, but not really dangerous and those which might require you to halt treatment and seek immediate medical advice.

The side effects that are considered as dangerous are any signs and symptoms indicative of:

  • Allergic reaction
  • Stroke
  • Heart attack
  • Breast cancer
  • Blood clot

Other documented side effects include:

Frequency of occurrence Side effects
Common (1 in 10 women) Headaches, acne, nausea, irregular periods, lack of periods, decreased libido, breast pain, weight gain
Uncommon (1 in 100 women) Vaginal infections, eye irritability and sensitivity, hair loss, painful periods, ovarian cysts, drowsiness
Rare (1 in 1000 women) Rash, hives, painful blue to red skin lumps


Please note that this is not a complete list of all documented side effects. For a more comprehensive overview, please consult the official patient information leaflet that you can find within your pack of Cerelle.