Desogestrel 150mcg / Ethinylestradiol 20mcg (e.g. Mercilon®) is a combined hormonal contraceptive with a 21-day regimen. Learn how to use the medication, its common side effects, special precautions to watch out for, and more.

What is this medication for?

Desogestrel 150mcg / Ethinylestradiol 20mcg (e.g. Mercilon®) is a combined hormonal contraceptive with a 21-day regimen. It contains two types of female hormones, estrogen (ethinylestradiol) and progestogen (desogestrel). This medication can help prevent ovulation and regulates other naturally occurring hormones in the body. When taken correctly, this prevents pregnancy and promotes regular menstrual bleeding. 

How should I take or use this medication?

• Do not stop taking your medication without checking with your healthcare professional.
• If you are switching from other forms of contraception, please seek advice from your healthcare professional. 
• You should take this medication after food.
• You may start taking this medication on the first or second day of your menses (if this is your first time taking hormonal contraceptives or restarting this medication after a break).
• If you are also using it for contraceptive purposes, a barrier method of contraception (e.g. condoms), is recommended for the first 7 days of taking this medication for the first time.
• You should take one tablet daily for 21 days in a row, preferably at the same time every day.  After completion of the pack, there will be 7 days where you do not need to take any tablets (7-day tablet-free interval), during which you will experience withdrawal bleeding (menses) within two to three days after the last tablet.
• Start taking your next pack of medication after the 7-day tablet-free days, even if you are still having menstrual bleeding. 

What should I do if I forget to take or use this medication?

If you forget to take a dose, you must follow the steps below to ensure that the contraceptive effect is not reduced.

Within 12 hours:

Take the missed tablet as soon as you remember. Take the next tablet at your usual time. 

More than 12 hours:

If the missed tablet is within

• Week 1 of the pack: 
  • Take the missed tablet as soon as you remember, even if it means taking 2 tablets at the same time. 
  • Continue to take your tablets at your usual time on the next day. 
  • Use a barrier method such as a condom for the next 7 days.

If sexual intercourse happened in the previous 7 days, you may be pregnant. See your doctor for advice as soon as possible. 

• Week 2 of the pack: 
  • Take the missed tablet as soon as you remember, even if it means taking 2 tablets at the same time. 
  • Continue to take your tablets at your usual time on the next day. 
  • If you have taken your tablets correctly in the 7 days before the first missed tablet, there is no need to use extra contraceptive precautions. However, if this is not the case, or you have missed more than 1 tablet, use a barrier method such as a condom for the next 7 days.

• Week 3 of the pack: 

Depending on whether you have taken your tablets correctly in the 7 days before the first missed tablet, you would have to follow the following options: 

**If you miss your period (especially with missed tablets), check with your doctor to find out if you are pregnant before continuing to take the next cycle of contraceptives.

If you vomit or suffer from diarrhea within 3 to 4 hours of taking this medication, the tablet may not be absorbed. This is considered a missed dose. You should then follow the instructions above. 

What precautions should I take when taking or using this medication?

Inform your healthcare professional if: 

• You are allergic to this medication or any of the other ingredients of this medication
• You are pregnant, planning to become pregnant, or breastfeeding 
• You are taking any other medications, including supplements, traditional medications and herbal remedies
• You have a history of or current medical conditions such as liver problems, stroke, clotting disorders, heart diseases, migraine headaches, epilepsy (fits), diabetes or cancer
• You are a smoker 

What are some common side effects of this medication?

• Spotting or bleeding may occur between your periods during the first few months of taking oral contraceptives. However, if this continues after the third month, check with your doctor. 
• Nausea, vomiting, bloating and stomach cramps
  • Take the medication after food to reduce these side effects 
• Breast tenderness
• Headache or migraine
  • You may take painkillers such as Paracetamol to manage headaches 
• Unable to tolerate contact lenses
• Weight changes, mood swings 
  • Take medication at the same time every day to avoid huge changes in the hormone levels in your body
• Pigmentation of the skin
  • Apply sunblock when you are outdoors and avoid long hours of sun exposure

Inform your doctor if the side effects above become severe and bother you.

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following: 

• Swollen face/eyes/lips/tongue
• Difficulty in breathing
• Itchy skin rashes over your whole body

Using a combined hormonal medication increases a woman’s risk of developing blood clots compared to a woman not taking any combined hormonal contraception. The risk of developing blood clot in a vein is highest during the first year a woman uses the medication. Other risk factors of developing blood clots include smoking and obesity. However, the formation of blood clot is rare and the doctor would have considered the risks against the benefits before making the recommendation. 

The symptoms of blood clot may include one or more of the following:

• Any unusual sudden cough, breathlessness or difficulty in breathing 
• Severe pain in the chest which may reach the left arm
• Severe pain in legs or swelling in either of your legs
• Weakness or numbness in any part of your body
• Change in your speech, including slurring of words
• Change in your senses of hearing, smell or taste
• Vision changes such as loss of vision or blurred vision 

Other rare but serious effects include: 

• Unusual, severe or long lasting headache or worsening of migraine 
• Dizziness or fainting
• Severe pain in your abdomen
• Dark urine or light coloured stools
• Nausea and vomiting
• Loss of appetite
• Yellowing of eyes or skin

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

What food or medication should I avoid when I take or use this medication?

Some medications including antibiotics and antifungals may affect how the medication works or be affected by the medication.  Please inform your other healthcare professionals about this medication which you are taking if you are seeing them for other medical conditions. 

How should I store this medication?

Store in a cool and dry place, away from direct sunlight at room temperature. Keep this medication away from children. 

How do I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

Disclaimer

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore.

Last updated on May 2024.