Nacrez is a branded progesterone-only birth control pill (mini-pill) that is manufactured and marketed in the UK by Teva pharmaceutical company. As opposed to more conventional combined hormonal contraceptive pills, Nacrez contains just one active ingredient, a synthetic hormone desogestrel which is a manmade bioequivalent to naturally-occurring sex hormone progesterone. Another specific of Nacrez contraceptive tablets is the fact that it is intended to be taken throughout the menstrual cycle, as opposed to commonly used 21-day or 24-day pills which are more common among combined oral contraceptives (COCs). However, regardless of these differences, Nacrez is just as effective as the alternatives, but more on that in a moment!

What’s on this page?

Just how reliable is Nacrez?

The medical community more or less agrees progesterone only pills (POPs) or mini-pills are somewhat less reliable than their counterparts, combined hormonal contraceptives. But, this may be a bit misleading. It is not that progesterone-only birth control pills such as Nacrez are less effective, they just provide a single layer of protection as opposed to COCs which provide two, thanks to two active ingredients – synthetic progesterone and synthetic oestrogen. However, it is important to note that the protection provided by the presence of synthetic oestrogen is not considered to be reliable in itself, but only as an addition to protection provided by synthetic progesterone – something that is, obviously, also provided by Nacrez and other mini-pills. For more information on the specifics, please scroll down to the section of the text on Nacrez mechanism of action.

What can compromise the efficiency of Nacrez?

Another thing important to note is that the optimal levels of protection provided by Nacrez – advertised as 99% protection against pregnancy – can be successfully maintained only if you make sure that you are using Nacrez properly, exactly as instructed by your prescriber and in line with the guidelines provided in the official patient information leaflet that is issued within every pack of the birth control pill.

Likewise, in order to prevent any decrease in efficiency of Nacrez, you should get familiar with all the medications, remedies and foodstuffs which are known to impair the reliability of this contraceptive pill. Of course, in some cases you might not be able to avoid the medications in questions, so you should use additional barrier contraception during the period when efficiency of Nacrez is less than optimal. For more information on the exact substances that might cause problems as well as estimates on how long the impairment might last, please refer to the official patient information leaflet.

How does Nacrez work?

Progesterone-only mini-pills rely on synthetic, manmade equivalent of naturally occurring sex hormone progesterone in order to influence the perceived balance of hormones in the body. This mechanism of action relies on the crucial role of progesterone in triggering ovulation, the release of egg cell from the ovaries to the fallopian tubes, where it can get fertilised by sperm.

However, with synthetic progesterone, desogestrel in case of Nacrez, the body will mistake the active ingredient for naturally produced progesterone, causing it to “think” that the ovulation already took place – as indicated by perceived increase in the levels of progesterone. As a consequence, the ovulation won’t take place and the egg cell will not be released, thus making conception impossible. This mechanism of action is same for both mini-pills and combined oral contraceptives. Synthetic oestrogen present in the latter will offer an additional level of protection by increasing the thickness of the vaginal fluids, making it harder for the sperm to navigate through the cervix. However, this mechanism of action wouldn’t be considered to be reliable on itself, without progesterone-mimicking activity, making the gap in efficiency between combined contraceptive pills and mini-pills essentially negligible. This is exactly why POPs such as Nacrez or Norgeston for example are so popular.

Can I buy Nacrez online in the UK?

Birth control pills of any kind, including progesterone-only mini-pills such as Nacrez 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 Nacrez 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 Nacrez.

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 Nacrez?

As was mentioned, in order to ensure the highest possible level of protection when using Nacrez, you should make sure that you are taking this birth control pill properly, exactly as instructed by your prescriber and in line with the guidelines provided in the patient information leaflet. Failure to do so will result in compromised efficiency and reduced level of protection.

Below, we will provide you with some of the most central guidelines that you should keep in mind when taking Nacrez. However, you should note that what follows is just a brief overview and as such it can never be used as a substitute for the official information or the doctor’s advice.

  • Always take exactly as instructed
  • You should take one pill daily, each day at the same time
  • For information on when and how to commence treatment, please consult the patient information leaflet
  • The strip containing Nacrez tablets is marked with arrows and labels that should help you keep track of the treatment and ensure you hadn’t missed any pills
  • Take the tablets whole without chewing or breaking them
  • If you forget to take a pill, consult the patient information leaflet on how to proceed

What are Nacrez side effects?

Birth control pills are known to come with certain potential side effects. And while they certainly won’t manifest in everybody using the medication, it is still important to get familiar with them prior to commencing treatment so that you will be able to act accordingly.

It is very important to be able to differentiate between those side effects which might require you to stop treatment and seek immediate medical advice and those which are uncomfortable, but otherwise benign. The former group includes all signs and symptoms indicative of:

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

Other documented side effects include:

Common (1 in 10 women) Uncommon (1 in 100 women) Rare (1 in 1000 women)
·       Headaches

·       Mood swings

·       Loss of libido

·       Weight fluctuations

·       Nausea

·       General malaise

·       Breast pain

·       Missing periods

·       Vaginal infection

·       Hair loss

·       Ovarian cysts

·       Painful periods

·       Drowsiness

·       Eye irritation



·       Skin rash

·       Hives

·       Erythema nodosum







Please note that this is not a complete list of all documented side effects. For a more comprehensive overview, please refer to the official patient information leaflet that is issued within every pack of Nacrez.