Mercilon is a brand of the combined oral contraceptive pill. It is taken to prevent an unwanted pregnancy, and is an effective method of contraception when taken as prescribed.
- Mercilon is a combined oral contraceptive pill
- It contains synthetic versions of the natural hormones produced by a woman’s body
- Mercilon is the brand name, and the active ingredients are desogestrel (synthetic progesterone) and ethinylestradiol (synthetic oestrogen)
- It is taken if you want to avoid getting pregnant whilst sexually active
- The combined pill is not suitable for all women, as it can increase the risk of blood clots and some cancers
- Mercilon does not protect against sexually transmitted infections
- It is important to read the patient leaflet for a full list of side effects and cautions.
How Does Mercilon Work?
Mercilon contains synthetic versions of two hormones that would naturally be produced by a woman’s body. When taken in the dose contained within the pill, the active ingredients prevent you from getting pregnant.
Mercilon works in three ways to prevent a pregnancy from occurring.
- An egg is prevented from being released from the ovary
- The mucus around the cervix becomes thicker to stop sperm from entering the uterus
- The lining of the uterus remains thin, so that a fertilised egg would be unable to implant and begin developing.
The combined pill is one of the most effective reversible forms of contraception. In this context, the word reversible means that if you stop taking it, you could get pregnant. It is therefore not a permanent choice and should not prevent you from getting pregnant in future if you wanted to.
How is Mercilon Taken?
One Mercilon tablet should be taken every day for 21 days in a row. Contraceptive cover starts on day one.
After this, you will have a 7 day break where you do not take Mercilon. During this time, you are likely to have a withdrawal bleed. This is a bleed that is like a period.
At the end of the 7 day break, you start a new strip of 21 tablets and continue this cycle to maintain your contraceptive cover.
If you are not currently taking an oral contraceptive pill, you should begin taking Mercilon on the first day of your period.
If you are changing from another combined oral contraceptive, take your first tablet of Mercilon on the first day immediately after the end of the previous oral contraceptive course.
If you are changing from a progesterone-only pill (POP or mini-pill), you should take the first tablet of Mercilon on the first day of bleeding, even if you have already taken a POP that day.
Starting Mercilon in this way offers immediate contraceptive cover.
You should take Mercilon at the same time every day. If you forget to take a pill, take it as soon as you remember. If the delay is less than 12 hours, contraceptive protection is maintained. If you miss your pill by more than 12 hours, additional contraception will be required, such as condoms.
Dosage of Mercilon
Each Mercilon tablet contains 150 micrograms of desogestrel (synthetic progesterone) and 20 micrograms of ethinylestradiol (synthetic oestrogen). This dose of oestrogen is slightly lower than in other combined oral contraceptive pills.
Are there any Side Effects?
Like all medications, Mercilon can have some side effects. The most common side effects include:
- Nausea (feeling sick)
- Abdominal pain
- Weight gain
- Altered mood or depression
- Breast tenderness or pain.
These side effects are likely to settle down, but if they persist or become troublesome you should speak to your doctor for further advice.
Occasionally, using a combined oral contraceptive can have serious side effects. If any of the following occur, you must contact your doctor straight away:
- Sudden, severe chest pain
- Swelling or pain in one of your legs
- Severe stomach pain
- Sudden breathlessness or coughing up blood
- Severe headache, loss of sight or hearing, or difficulty swallowing
- A fainting attack, fit, or numbness to one side of your body
- Yellowing of the skin or whites of the eyes (jaundice).
Serious allergic reactions happen very rarely. If you have a severe allergic reaction (anaphylaxis) including breathlessness, lip swelling or tongue swelling, call 999 immediately.
Mercilon may not be suitable for everyone. You should tell your prescriber if you:
- Are at high risk of blood clots to the legs or lungs
- Have ever had a deep vein thrombosis or pulmonary embolism (DVT or PE, clots to the legs or lungs)
- Have a blood clotting disorder
- Are awaiting major surgery that will cause prolonged immobilisation
- Have ever had a heart attack or stroke, or have angina
- Have migraines
- Have diabetes
- Have severe hypertension (high blood pressure)
- Have, or have had, breast cancer or cervical cancer
- Have otosclerosis
- Have gallstones
- Have liver or kidney disease
- Have systemic lupus erythematosus (SLE or lupus)
- Have sickle cell anaemia
- Have hereditary angioedema
- Have any allergies
- Might be pregnant, or are breastfeeding.
Mercilon may not be suitable if a close family member has been diagnosed with a previous PE (lung clot) or DVT (leg clot), breast cancer or cervical cancer.
Some medications can interact with Mercilon. You may be advised that Mercilon will not suit you if you already take:
- Anti-seizure medications including phenytoin, carbamazepine, topiramate and phenobarbitone or other barbiturates
- Certain antibiotics or antifungal medications
- Antiretroviral medications including ritonavir, nelfinavir and nevirapine
- St John’s Wort (Hypericum perforatum).
Because Mercilon may not suit everyone, we will complete a Consultation with you including a health questionnaire. This will ensure that the medication will be suitable for you.
A qualified prescriber will review your current medications, including any herbal remedies or supplements, to ensure that Mercilon will not interact with them.