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Mercilon ®

Mercilon is a pill that stops you getting pregnant. It can make your periods lighter too.

Sign up to an EveAdam subscription to buy Mercilon online, and get next-day delivery of your pill from a UK pharmacy.

Treatments from only £6.99 per month

Buy Mercilon online. Get your pill on subscription with EveAdam.

Mercilon is a combined contraceptive pill. It has two hormones in it that work like progesterone and oestrogen. If you take it correctly, there’s less than a 1% chance that you’ll get pregnant over a whole year.

You can buy Mercilon online and get it delivered to your door with an EveAdam subscription plan. It starts with a consultation with one of our licensed prescribers. They’ll check your medical background and talk you through the best treatment options for you. Once you’ve chosen your pill, our prescriber creates a prescription, which is dispensed by our pharmacy. You can then decide how regularly you’d like to receive your pill, and the quantity too.

We’ll deliver it to your home by special courier, and that’s it. No faff. Just easier contraception.

How does Mercilon work?

Like other combined pills, Mercilon reduces your pregnancy risk in three ways.

The two hormones in Mercilon adjust the body’s hormone balance, to stop the ovaries from releasing an egg (ovulation).

Mercilon also thickens the mucus in the neck of the womb (cervix) which makes it harder for sperm to move through to the womb (or uterus) to fertilise an egg, while the lining of the womb is made thinner. If the uterine lining is thinner, it’s less likely that a fertilised egg will be able to latch on to it, and develop.

When the lining of the uterus doesn’t build up as much, you may find that your periods are way lighter when you’re taking combined pills.

So in short – Mercilon covers a lot of bases.

How effective is Mercilon?

Really really effective, if you take it correctly. We’re talking more than 99% if you take it at the same time every day, without missing any pills.

So to put this into context, out of 100 women taking the pill over 12 months, less than one will get pregnant.

If you make mistakes when you take Mercilon, or if you occasionally miss pills, its effectiveness decreases slightly (to around 91%). So about 9 women in every 100 will get pregnant in a year.

Is there more than one Mercilon dosage?

Sort of. Mercilon is a lower dose version of Marvelon. It has slightly less oestrogen in it. So if you take Mercilon and find it doesn’t quite give you that balance you need to keep period symptoms under control, you might be good on Marvelon.

You can switch pills mid-way through your subscription with EveAdam. All you need to do is sign in and drop the prescriber a message, and they’ll go through the options with you.

Page reviewed by:
Dr Daniel Atkinson
Dr Daniel Atkinson
GP Clinical Lead
Visit author profile
Last updated 22/06/2021

What you need to know about Mercilon

What is Mercilon?

Mercilon is a low-dose combined hormonal contraceptive pill, and contains a lower dose of oestrogen than some other combined pills. Because it has less oestrogen in it, it may cause fewer side effects for some women; especially women who are sensitive to higher doses of oestrogen.

It’s a 21-day pill, so you take it for 21 days, and then have a 7-day pill-free break, and keep repeating this course of treatment. But you can also take it on a continuous basis (1 pill every day with no pill-free break) or on an extended basis (1 pill every day for 9 weeks, followed by no pills for the next 4 or 7 days).

If you’d prefer to take it on a continuous or an extended basis, our clinician can advise you on this.

What ingredients are in Mercilon?

Can I take Mercilon for acne?

How can I buy Mercilon online?

How to take Mercilon pills

Mercilon comes in strips of 21 pills, with a day of the week marked alongside each pill. You should take the pills according to the correct day of the week, and follow the direction of the arrows on the strip.

If you start to take Mercilon on the first day of your period, your protection from pregnancy is immediate.

If your period has already started, start taking Mercilon on day 5 of your cycle whether your bleeding has stopped or not. You’ll need to use additional contraception, such as condoms, for the first 7 days, while the pill takes effect in the body.

Take 1 pill at the same time every day, until you have used all 21 pills. You can swallow the pills with water if you’d prefer to, but don’t chew them.

After you’ve taken all 21 pills, have a 7-day pill-free break. So if you take the last pill from the strip on a Friday, take the first pill from the new strip on the Saturday of the following week.

A few days after taking the last pill from the strip, you should get a withdrawal bleed, like a period. This bleed may still be continuing when you start your next strip of pills; this is fine - even if you’re still bleeding, start your new strip of pills.

You should always read the patient information leaflet that comes with your treatment before using Mercilon.

Are there other ways you can take Mercilon?

What to do about a Mercilon missed pill

Can I delay my period with Mercilon?

What are the most common Mercilon side effects?

Headache, sore or tender breasts, nausea and abdominal pain are all common side effects when taking the combined pill. These symptoms are often mild, and disappear after a few weeks. But if you find that they persist, or if you get any side effects that cause you more discomfort, let our clinician know. They may recommend that you switch to a different pill, and can advise you on alternatives that may be more suitable for you.

If you experience severe side effects which are more severe, you should seek emergency medical attention at a hospital. You can find more information about this in the patient information leaflet that comes with your treatment.

Can Mercilon cause weight gain?

What other side effects can the pill cause?

Mercilon vs Yasmin: which is better?

Yasmin, like Mercilon, is a 21-day combined pill, and there’s no difference between the two in terms of how they work.

Because they’re not made by the same companies (Yasmin is made by Bayer, while Mercilon is made by Merck Sharp and Dohme) the pills themselves may differ in appearance, and the packaging isn’t the same. But the only significant difference between the two is the hormones that are in them.

Both pills contain ethinylestradiol, which is a form of oestrogen, but they have two different forms of progesterone in them. Mercilon contains a progestogen called desogestrel, whereas Yasmin contains a progestogen known as drospirenone.

Besides its primary role in Yasmin pills as a hormone that prevents pregnancy, drospirenone has shown to be particularly effective at treating symptoms of acne. So if you’re looking for a 21-day pill that offers protection from pregnancy but also has the added benefit of helping to tackle acne (in some cases), Yasmin may be an especially suitable option for you.

Mercilon contains a lower dose of oestrogen than some other pills, so if you’re sensitive to oestrogen, or to the side effects that it can cause, it may be a particularly appropriate pill for you.

So it’s really a question of your medical background, and what sort of symptoms and side effects you’re prone to, when it comes to which pill is best for you.

What’s the difference between Marvelon and Mercilon?

If I want to switch from Mercilon to another pill, what should I do?

Mercilon safety information

Before you start using Mercilon, make sure that you read the patient information leaflet that comes with your treatment. 

Can Mercilon interact with other medications?

Like other combined pills, Mercilon can interact with other medications, and certain treatments may interfere with how effective it is.

If you’ve recently used, or are currently using, other treatments, it’s very important that you tell our prescriber during your consultation.

Read more about the combined pill and interactions.

Is Mercilon suitable for everyone?


[1] Słopień, R, Et al. 2000. Use of oral contraceptives for management of acne vulgaris and hirsutism in women of reproductive and late reproductive age. Menopause Review. Poland. PTMA.,4,32467,0,1.html [Accessed 1st May 2021].

[2] Mayeda, E.R. Et al. 2014. Weight and Body Composition Changes During Oral Contraceptive Use in Obese and Normal Weight Women. Journal of Women’s Health. U.S.A. NCBI. [Accessed May 6th 2021].