Mercilon is a low dose combined contraceptive pill that's suitable for most women to take every day to prevent pregnancy. It's up to 99% effective when taken as prescribed and can also be used to help with heavy and painful periods.

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from £25.00

Product details

Mercilon is an oral contraceptive pill that is suitable for most women to take every day to prevent pregnancy and can be used to help with heavy and painful periods.

You can buy Mercilon online with a prescription from a doctor if it’s right for you, if not, the doctor will be able to advise you on the alternatives.

Dr Simran Deo Medical Editor

Medically reviewed by

Dr Simran Deo

Last reviewed: 22 Mar 2021

Mercilon Prices

Pack Size Price
20 mcg - 3 x 21 tablet(s) £25.00
20 mcg - 6 x 21 tablet(s) £35.00

How it Works

About Mercilon

What is Mercilon?

Mercilon is a low-dose combined oral contraceptive pill. It is taken daily to prevent pregnancy, and can also be used to treat painful or heavy periods. Mercilon contains artificial versions of two different female hormones, 20mcg of oestrogen (ethinylestradiol) and 150mcg of progesterone (desogestrel).

Mercilon contains a lower dose of oestrogen (ethinylestradiol) than other combination pills, making it more suited to some women as it has a lower chance of causing side effects.

Is Mercilon the same as Marvelon?

No, though they are similar. Mercilon and Marvelon both contain the same active ingredients, but Mercilon contains a lower dosage of oestrogen (ethinylestradiol). This means that Mercilon has a lower chance of causing side effects than Marvelon.

How to buy Mercilon

You can buy Mercilon using the confidential service from Superdrug Online Doctor even if you have never taken it before by following these steps:

  1. Fill out the short online questionnaire.
  2. One of our doctors will review your answers and make sure that it is safe to prescribe you Mercilon.
  3. You can then buy the medication and choose to have it delivered to an address of your choice in a discreet package or to collect it from a Superdrug store.

If you are buying medication online, always check that the site has been licensed using the Government’s online checker.

Can you get Mercilon over the counter?

All oral contraceptive pills are currently prescription-only, which means you cannot buy them over the counter and must have a prescription from a doctor.

Can you get Mercilon on the NHS?

Whether or not Mercilon is available for free on the NHS depends on your local area guidelines. Talk to your GP or your local sexual health clinic to find out more.

Is Mercilon safe?

If you have a prescription for Mercilon, then it is safe for you to take.

As with all combined oral contraceptive pills, the oestrogen it contains makes it unsuitable for women with certain medical conditions. Your doctor understands these conditions and will not prescribe you Mercilon unless it is safe to do so. In this case, you may be prescribed a progesterone-only mini pill.

Mercilon is a commonly prescribed pill in the UK and it has the same risk factors associated with it as other combined oral contraceptive pills.

How does Mercilon work?

The combined contraceptive pill works by releasing and regulating the female hormones oestrogen and progesterone in your body. This prevents pregnancy by:

  • Stopping ovulation, so you do not release an egg every month.
  • Increasing the thickness of the fluid around the neck of the womb, making it harder for the sperm to reach an egg.
  • Reducing the lining of the womb, making it more difficult for a fertilised egg to implant itself.

How long does Mercilon take to work?

How long Mercilon takes to work depends on when you start taking it. Doctors recommend that you take it in the first 5 days of your period for immediate protection from pregnancy. Otherwise, start taking it on Day 5 of your cycle and use additional contraception for 7 days.

How effective is Mercilon?

If you take Mercilon at the right time each day, it is over 99% effective in preventing pregnancy. In reality, this is closer to 91% because people forget to take it at the right time, suffer from vomiting or diarrhoea (which can limit its absorption by your body) or take other medications which interact with it.

How to take Mercilon

Mercilon comes in strips of 21 tablets. Each tablet is marked with the day of the week:

  • Start with the tablet for the appropriate day from the top part of the strip.
  • Swallow one tablet whole with water at the same time each day for the whole strip.
  • After 21 days, you take a break for 7-days.
  • During this time, you will have a ‘withdrawal bleed’, similar to your period.
  • You are protected from pregnancy during this period.
  • Start your next strip of pills on the same day each time.

When should I start taking Mercilon?

You can start taking Mercilon at any time in your menstrual cycle. If you want to be immediately protected from pregnancy, you should start taking it in the first 5 days of your period. Otherwise, you should use additional protection for 7 days.

If you are changing to Mercilon from another contraceptive pill or other contraception, follow the instructions given by your doctor or in the patient information leaflet:

  • If you are changing from another 21-day combined pill, you should start taking Mercilon immediately at the end of your strip. You will be protected from pregnancy immediately but you will not have a bleed until the end of your first strip of Mercilon.
  • If you are changing from a 28-day combined pill, you should start taking Mercilon after the active pills finish. You will be protected from pregnancy immediately but you will not have a bleed until the end of your first strip of Mercilon.
  • If you are changing from the mini pill, start taking Mercilon on the first day of your period. You will have protection immediately.
  • If you are changing from the mini pill but don’t have bleeding, you can start taking Mercilon on any day of your cycle but you must use additional contraception for 7 days.
  • If you are changing from an injection or intrauterine device (IUD), you can start taking Mercilon the day the injection was due or your device removed. You will need to use additional contraception for 7 days.

Can I take Mercilon without a break?

Yes, you can take Mercilon every day and not have the 7-day break. This can help as a treatment for heavy and painful periods. You should discuss this with your doctor.

What happens if I miss a Mercilon pill?

If you miss taking your pill, what you need to do depends on how many pills you have missed.

If you have missed one pill or start your new strip a day late:

  • Take the pill you missed as soon as possible, even if this means taking two tablets at once.
  • You will still be protected from pregnancy so you do not need emergency contraception.
  • If your strip ends within the next 6 days, you should skip your 7-day break and continue with the next strip instead.

If you have diarrhoea or are sick within 3 to 4 hours of taking your pill, you should act as though you have missed a pill as your body may not have fully absorbed the hormones. If your sickness continues, talk to a health professional to get advice but use additional protection to ensure you are protected from pregnancy.

If you have missed more than 2 pills:

  • Take the pill as usual once you remember but use additional protection for the next 7 days.
  • If you’ve had unprotected sex since you missed your pill, you’ll need to use emergency contraception.

If you have to take emergency contraception while on Mercilon, check with the health professional about when you should take your pill and when you will be protected from pregnancy.

Can I take Mercilon to delay my period?

Yes, you can delay your period if you start a new strip of Mercilon immediately after you finish the previous one and do not take the 7-day break. Talk to your doctor if you plan to do this regularly.

Can I use Mercilon as an emergency contraceptive?

No, Mercilon is a contraceptive pill that prevents pregnancy, whereas emergency contraception is used when there is a possibility that you have become pregnant through having unprotected sex.

Can I take Mercilon after a miscarriage or termination?

Yes, it is possible to start taking the combined pill immediately after a miscarriage or termination, but you must first discuss options with your doctor.

Can I take Mercilon if I am breastfeeding?

The combined pill is not recommended for breastfeeding mothers due to the oestrogen it contains. Tell your doctor that you are breastfeeding and would like advice on which is the best pill to take.

Can I drink while taking Mercilon?

Yes, it is safe to drink alcohol while taking Mercilon. Alcohol does not interact with Mercilon, so it doesn’t cause the pill to become less effective.

Can I take painkillers when taking Mercilon?

Yes, it is safe to use painkillers while taking Mercilon. Painkillers do not make Mercilon any less effective..

Mercilon side effects

Many women who take Mercilon do not experience side effects. For those who do, the side effects can vary from person to person and in severity. Side effects are more common in the first 3 months of taking Mercilon when your body is getting used to the hormonal changes.

If the side effects are not manageable or do not disappear after 3 months, talk to your doctor. as they may suggest trying a different pill.

In very rare cases, a side effect of taking Mercilon is that you can develop a blood clot. The Patient Information Leaflet has information on how to recognise a blood clot. Signs include stabbing chest pain, coughing up blood, shortness of breath, immediate loss of vision, unexplained swelling or tenderness in one or both legs. If you develop these symptoms, you should stop taking Mercilon immediately and seek urgent medical help.

Common side effects (may affect up to 1 in 10 people):

  • Headache
  • Weight gain
  • Nausea or stomach ache
  • Mood changes/low mood
  • Tender breasts

Uncommon (may affect up to 1 in 100 people):

  • Migraine
  • Swollen hands, ankles or feet
  • Reduced libido
  • Being sick or having diarrhoea
  • Rash or hives
  • Enlargement of breasts

Rare (may affect up to 1 in 1000 people)

  • Changes in secretions from the vagina or breasts
  • Eye pain if you wear contact lenses
  • Harmful blood clots
  • Increased libido
  • Weight changes
  • Bruise-like swellings to the shins
  • Skin condition knowns as erythema multiforme

Can Mercilon help with painful and heavy periods?

The contraceptive pill regulates hormones in your body which can help some women treat painful periods.

Does Mercilon make your breasts grow?

Some women report an increase in the size of their breasts when taking Mercilon due to the changes caused by the hormones in your body. This usually settles down after the first 3 months.

Does Mercilon increase your risk of blood clots?

The risk of developing a blood clot when you are not taking an oral contraceptive pill is 2 in 10,000, whereas when you are taking Mercilon this risk is 9-12 in 10,000 women. This is a relatively low risk overall but factors such as family history, weight, age, whether you plan to spend a long time on a plane and whether you have just given birth can increase them. The risk is also higher in the first year that you start taking Mercilon and it returns to normal within a few weeks of when you stop taking it.

Does the Mercilon help acne?

It can. The hormonal changes introduced by taking Mercilon can reduce the production of sebum, which is the oily substance that causes acne.

Can taking Mercilon cause mood swings or make you depressed?

Some women report that being on Mercilon caused sudden changes in mood or low mood. The research into this can neither prove nor disprove this link. If you feel this is the case for you, talk to your doctor about changing pills.

Can Mercilon cause changes to your weight?

Some women report gaining weight when they take Mercilon but again there is no scientific evidence to prove either way that taking the pill either increases or decreases your weight.

Can Mercilon give you low libido?

Some women report that taking the combined pill has an impact on their sex drive due to the changes in hormones in their body. If you are worried that this has happened to you, talk to your GP who may suggest trying a contraceptive pill with different hormones.

Does Mercilon stop periods?

You still get periods when you take Mercilon because you have a 7-day break during which you have a withdrawal bleed or period. If you want to delay your period, you can take Mercilon back to back. Talk to your doctor if you do this regularly.

Who shouldn't take Mercilon?

As Mercilon contains both oestrogen and progesterone, there are specific medical conditions where doctors do not advise that women take Mercilon as an oral contraceptive. In this case, the GP may recommend that you try the progesterone-only mini pill.

It is essential to tell the prescribing GP if any of these factors apply to you:

  • smoke or stopped smoking less than a year ago and are 35 or older
  • need an operation which means you will be off your feet for an extended period of time
  • are very overweight
  • suspect you might be pregnant
  • breastfeeding
  • take certain medicines
  • have high blood pressure
  • have or have had blood clots on a vein (eg, your leg) or lungs or other organs
  • have a familial history of blood clots under the age of 45
  • have or have had a heart attack, stroke or heart abnormality
  • have or have had severe migraines
  • have or have had breast cancer or cancer of the ovary or womb lining
  • have or have had a disease of the gallbladder or liver
  • have or have had diabetes

Can I take Mercilon if I am taking other medicines?

If you are taking other medicines or herbal supplements, you should tell the doctor prescribing you Mercilon. Likewise, if you are already taking Mercilon and a doctor prescribes you another medication you should tell them. This is because some medicines interact with the combined pill and make it less effective at preventing pregnancy.

Medications for the treatment of the following conditions are known to interact with Mercilon:

  • epilepsy
  • tuberculosis
  • HIV infection
  • hepatitis C virus infection
  • other infectious diseases
  • high blood pressure in the blood vessels of the lungs
  • depressive mood

What are the risks of taking Mercilon?

Mercilon is safe to take as long as you have been prescribed it by a doctor who understands your medical history and conditions.

However, with the combined oral contraceptive pill, your risk of developing blood clots and certain types of cancer is slightly increased than if you are not taking the pill. Certain medical conditions can increase your risk in these instances, so it’s important to discuss your medical history with your doctor.

Blood clots: the oestrogen in Mercilon can cause your blood to clot more easily, and blood clots can lead to deep vein thrombosis (clot in your leg), pulmonary embolism (clot in your lung), stroke and heart attack. The risk is low (between 9-12 out of 10,000 women) but it is higher when compared to women who are taking the mini pill (between 5-7 out of 10,000 women) and those not taking any oral contraceptive (2 out of 10,000 women). The risk decreases after your first year of taking Mercilon for the first time and returns to normal within a few weeks of stopping taking Mercilon.

Cancer: research has shown that the combined pill can slightly increase the risk of developing breast and cervical cancer. However, 10 years after you stop taking the pill your risk goes back to normal. Your breast cancer risk is slightly higher if there is a history of breast cancer in your family, or you are very overweight.

Mercilon reviews

On Trustpilot, over 16,000 people have reviewed Superdrug Online Doctor. They give the service an average rating of 4.4 out of 5 stars.

On The Low Down, users of Mercilon rate it 3 stars out of 5. You can see how people view their moods, weight gain and sex drive while taking Mercilon.

On you can see how users rate birth control pills which are a combination of desogestrel and ethinylestradiol but not the exact same dose as Mercilon. The average rating was 5.4 out of 10.


Mercilon tablets Patient Information EMC [accessed 2 March 2021]

Combined Contraceptive Pill NHS  [accessed 2 March 2021]

Contraception (2018) NHS [accessed 2 March 2021]

Contraception – combined hormonal methods (2019) NICE [accessed 2 March 2021]

Contraceptives, hormonal (2019) NICE [accessed 2 March 2021]

How effective is contraception at preventing pregnancy? (2017) NHS [accessed 2 March 2021]

Patient Reviews