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Mercilon

Combined Pill|Active ingredient(s): Ethinylestradiol & Desogestrel|Manufacturer: Various

Close up of a woman taking a white pill

Take control of your cycle with Mercilon

  • Up to 99% effective when used correctly
  • Can make periods lighter and less painful
  • Can improve symptoms of acne
  • Simple daily dosing for 21 days, followed by a 7-day break
  • 150 mcg desogestrel/20 mcg ethinylestradiol tablets

How to take

A woman taking a tablet with a glass of water

Get started

Begin with the first Mercilon pill in your pack on day 1 of your period.

A hand holding a pen, marking a date on a calendar

Stay on track

Take one tablet daily for 21 days, followed by a 7-day break.

A woman in a pink t-shirt with her hands on her hips, shown from neck to torso

Reset your cycle

You may experience a withdrawal bleed during the 7-day break. After this, start your next pack.

What others say about Mercilon

Trustpilot review
14 reviews with score 4.6

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Price is all-inclusive.
Consultation is included.
Prescription is included.

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UK: Free next-day delivery.
Discreet packaging.

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Mercilon

What is Mercilon?

Mercilon is a combined oral contraceptive pill that is over 99% effective when used correctly. It contains synthetic versions of oestrogen (ethinylestradiol) and progestogen (desogestrel) to reliably and safely prevent pregnancy. It is sometimes referred to as “the pill”.

How does Mercilon work?

Mercilon works in three core ways to prevent pregnancy:

  • Prevents ovulation: Mercilon prevents the release of hormones that trigger ovulation. With no egg released, fertilisation cannot occur.
  • Thickens cervical mucus: Mercilon makes cervical mucus thicker, making it harder for sperm to pass through.
  • Alters the uterine lining: Mercilon modifies the lining of the womb, making it almost impossible for a fertilised egg to attach to it and grow.

Together, these actions provide highly effective, reliable protection against pregnancy.

How effective is Mercilon?

The combined oral contraceptive pill Mercilon is over 99% effective at preventing pregnancy when used correctly. In one study involving 1,684 women, four pregnancies occurred, with three of them a result of patients not taking Mercilon correctly. This displays a very high rate of effectiveness makingMercilon one of the most reliable contraceptive options on the market when used as directed.

Who can use it?

To be prescribed Mercilon from 121doc, you must be a woman over the age of 18.

Do not use Mercilon if you:

  • are allergic to any ingredient found in this medicine
  • have ever had a blood clot or a disorder affecting blood clotting
  • are due to have surgery or will be immobile for a long time
  • have ever had a heart attack or stroke
  • have angina pectoris (a condition causing severe chest pain) or transient ischaemic attack (temporary stroke symptoms)
  • experience migraines with aura
  • have ever had liver disease, a liver tumour, or kidney problems
  • have ever had breast cancer or cancer of the genital organs
  • experience unexplained vaginal bleeding

When should I start taking Mercilon?

When you take your first Mercilon pill depends on a few different factors. Follow this guide when starting your birth control:

  • If you have not used hormonal contraception in the last month:
    • Start on day 1 of your period for immediate protection.
    • Starting on days 2–5 requires extra protection (i.e. condoms) for 7 days.
  • If you’re switching from another combined pill, ring, or patch:
    • Start the day after your last active tablet or after removing your ring/patch.
    • Begin at the latest after your placebo or tablet-free days.
  • If you’re switching from a progestogen-only pill:
    • You can start on any day, but use extra protection for 7 days.
  • If you’re switching from an injection, implant, or hormonal IUD:
    • Start on the day your next injection is due, or the day your implant is removed. Use extra protection for 7 days.
  • After a miscarriage:
    • Follow your doctor’s advice.
  • After giving birth:
    • Start between 21 and 28 days after giving birth. Starting later requires extra protection for 7 days.

Can I take Mercilon without a break?

Yes, you can take Mercilon without the 7-day break to avoid breakthrough bleeding, however, you should discuss this with your doctor to make sure it’s safe. Generally, it is advised to take a 7-day break every month to keep your cycle under control, but in some cases this is not necessary.

What if I miss a pill?

If you forget to take a Mercilon pill, you may be less protected from pregnancy, but it depends on how long it has been since you were meant to take it. Follow this guide on what to do if you forget to take a pill:

How long it has been What to do Extra contraception needed?
Less than 12 hours Take the forgotten pill as soon as possible, and take your next one at the usual time. This may mean taking two pills in the same day No
More than 12 hours Take the most recently missed pill straight away, and your next one at the usual time. This may mean taking two pills in the same day Use condoms for the next 7 days. If there are fewer than 7 pills left in the pack, start your next strip without a break once you have finished your current one

Are there any side effects of Mercilon?

Yes, there are some potential side effects of Mercilon, although not everyone will get them. The most common Mercilon side effects are:

  • headache
  • weight gain
  • breast tenderness
  • depression or mood changes
  • stomach problems
  • migraine
  • fluid retention
  • vomiting
  • diarrhoea

This is not an exhaustive list. For a full list of Mercilon’s side effects, consult the patient information leaflet.

Does Mercilon cause weight gain?

Mercilon can cause weight gain, as it is listed as a common side effect. However, this is most likely a result of fluid retention (water weight), not fat gain. This happens as your body gets used to hormonal changes, and your weight should go back to normal within weeks. If it doesn’t, talk to your doctor to determine what the cause could be.

Does Mercilon cause acne?

While Mercilon can sometimes cause skin problems like acne, it is actually more likely to improve symptoms. A comprehensive review of over 31 clinical trials found that combined contraceptive pills like Mercilon reduced spots and improved skin.

Does Mercilon make your breasts bigger?

Mercilon can cause your breasts to enlarge slightly due to its hormones. This is likely due to fluid retention, and is often temporary. Once your body gets used to the medication, your breasts should go back to their normal size, but they may stay enlarged until you stop taking Mercilon.

Can I take Mercilon while breastfeeding?

No, Mercilon is not recommended while breastfeeding as it can interfere with your baby’s development. Research has found that this is likely due to a decrease in breast milk production due to the hormonal content of Mercilon. Talk to your doctor about alternative contraception options if you’re breastfeeding.

Can I get Mercilon without a prescription?

No, you cannot get Mercilon without a prescription. Safety is our number one priority at 121doc. For this reason, our doctors will only prescribe treatment if you meet the criteria in your online consultation.

A prescription from a trusted healthcare provider like 121doc ensures:

  • safety during treatment
  • effective results
  • monitoring of side effects
Medical review byDr. Caroline FontanaLast review 24 November 2025
Dr. Caroline Fontana

Note: You must complete a short online consultation so that our doctor can ensure that the treatment is suitable for you. The above pricing should only be used as a reference. The final decision to issue this treatment lies with the prescribing doctor.

Mercilon Overview

Type of medicine Combined oral contraceptive
Used for Contraception
Active ingredient Ethinylestradiol and Desogestrel
Works by Preventing ovulation, thickening cervical mucus to block sperm, and making the womb lining less suitable for implantation
Effective within Immediately when started on the first day of your menstrual cycle. After 7 days if started on days 2-5
Available as Film-coated tablets
Available dosage(s) Ethinylestradiol 20 mcg / Desogestrel 150 mcg
Usage instructions Take one tablet per day for 21 days, followed by a 7-day break
Packaging Blister pack containing 21 tablets
Manufacturer Organon

FAQs

What is included in the online consultation?
Will a doctor review my consultation?
What happens after I submit my order?
What services are included with my order?
Is the price all-inclusive?
What are my delivery options?
Is it safe to buy prescription medication online?
Is this service discreet?
What is included in the online consultation?

Our online consultations are in the format of short medical questionnaires. You will be asked general questions about your health and medical history, as well as specific medical questions relevant to the treatment you have chosen. We will also ask you for your payment and delivery details to complete the order.

Online consultations take no longer than 5 minutes to complete. All questions are necessary when issuing prescription medicines. It means that our doctors can make sure the treatment is safe and right for you.

Will a doctor review my consultation?

Yes, it is a legal requirement that all online consultations are reviewed by a registered doctor. This is to make sure the chosen treatment is safe and right for you to take. All personal information is stored securely and confidentially.

Please note, all orders are subject to doctor approval, and we cannot guarantee that your order will be approved.

What happens after I submit my order?

Your online consultation will be sent directly to our medical team, where it will be reviewed by on of our in-house doctors.

If a doctor approves you for treatment, they will issue a prescription. Your prescription will then be forwarded to our pharmacist, where you medication will be dispensed and dispatched for delivery.

What services are included with my order?

Every order includes:

  • Free consultation - your consultation will be personally reviewed by one of our registered doctors.
  • Free prescription - a doctor will issue you a prescription if approved for treatment.
  • Free delivery - we provide free express delivery across Europe, you should receive your order in 1-2 working days.
Is the price all-inclusive?

Yes, our service is all-inclusive and there are no hidden fees. All 121doc orders include a free online consultation, a free prescription and free express delivery.

What are my delivery options?

We offer several delivery options at no extra charge:

  • Next-day delivery
  • UPS Access Point - convenient parcel drop-off and collection near your home or work address
  • Nominated-day delivery - choose the most convenient day for delivery

All these options can be tracked and require a signature on delivery. If you are not in, a friend or relative can sign in your place.

Is it safe to buy prescription medication online?

It is safe to buy prescription medications online from genuine and reputable healthcare providers, like 121doc.

Our medical staff and facilities are registered with the relevant medical governing bodies. We also ensure your data is protected by adhering to European data privacy laws.

You can learn more about our certifications here.

Is this service discreet?

Our patients’ privacy is of utmost importance. All your medical information is securely stored and only viewed by our doctors. We do not share your details with third-parties. We are also closely adhere to data privacy laws.

All orders will only show on invoices, bank statements, etc. as ‘HHC Ltd’.

How does it work?

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Select a condition here or use the top menu. For every condition, we provide you with information as well as the treatments we currently offer. If you don’t know which is best for you, just click the 'Advise-me' button.

Treatments:

If you know what you want, the quickest way to find a specific medication is to use the search bar here.

Ordering:

Every order starts with an online consultation. We will ask you medical questions to make sure only treatment that is safe and effective is prescribed. We take into account your lifestyle, health and any other medications you’re currently using.

The consultation is completely free, and takes between 5 and 10 minutes of your time.

All your information is safe with us. We don’t share it with anyone unless you want us to.

Help:

If you need any guidance, you can call, message or email our customer service team via the ‘How can we help you?' section here.

Prescribe
Prescribe Our doctors review your order.
Free prescription

Review:

As soon as you place the order, one of our doctors will review your consultation. On working days, this usually takes around one hour.

Questions:

If the doctor has any additional questions, you will receive a phone call and an email. We understand you might be at work or busy. Our customer service representatives are always discreet and can call back at a more convenient time if necessary.

Our emails never contain any personal or medical information, only a link to your private account on our website (where you will find your messages).

Pharmacy:

Once our pharmacy receives your prescription, you will get a second email with your package tracking code.

Deliver
Deliver Expect your delivery the next working day.
Always free. Discreet packaging.
Free next-day delivery

Free:

All orders include next-day delivery. Alternatively, you can select a delivery date that suits you better.

Location:

We also provide a free UPS Access Point service. Pick up your package from one of many collection points across the UK.

With your tracking code, you will know the estimated delivery time. All we need is your signature (or a friend‘s or relative’s).

Discreet:

All parcels are plainly labelled; there is no logo or any indication of its contents. Inside, you will find your treatment as well as a patient leaflet in your chosen language.

Repeat
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10 to 15% off

Repeat:

With 121doc’s Subscribe & Save service, you can automatically receive your treatment every few weeks or months.

The order will be generated by us, using the information you provided (including delivery frequency). You don’t have to do anything. Payment is taken two days before shipping.

Subscribe:

There are two ways to subscribe. The first is during the order process. The second is via your profile here.

You can cancel or amend your repeat prescriptions at any time.

Save:

There are no sign-up fees with this service. Plus, you get a 10% discount off all future prescriptions, increasing to 15% after six orders!