Start taking danazol on the first day of your period unless you have been told otherwise. You can take the capsules either before or after meals.
It is important that you do not become pregnant while on danazol. Follow your doctor's advice about suitable contraception.
|Type of medicine||A gonadotrophin inhibitor|
|Used for||Endometriosis; breast cyst pain|
|Also called||Danol® (discontinued); Cyclomen® (in Canada)|
Danazol works by altering the levels of some of your body's hormones. It is used to treat a number of different conditions.
Endometriosis is a condition where tissue that normally lines the inside of your womb (uterus) is found elsewhere in your body, often in the pelvic area or abdomen. It can cause painful periods and persistent pain in the pelvic area, as well as other symptoms. By altering the levels of your hormones, danazol will help to relieve these symptoms.
Danazol is also prescribed to ease severe pain and tenderness associated with breast cyst disease (where other treatments have proved unhelpful). Breast cysts are small lumps which are found in the breast, but which are not cancerous.
In addition to the two conditions above, danazol is also prescribed by specialist doctors for people with a condition known as hereditary angio-oedema (although it is not licensed for this condition). If you have been prescribed it for this reason, please speak with your doctor if you have any questions about your treatment.
Before taking danazol
Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking danazol it is important that your doctor knows:
- If you are pregnant, trying for a baby or breastfeeding.
- If you have a heart condition.
- If you have any vaginal bleeding other than your regular period.
- If you have ever had an unwanted blood clot (thrombosis), or stroke.
- If you have any of the following conditions: epilepsy, diabetes (diabetes mellitus), high blood pressure, migraine, or a blood fat (lipid) disorder.
- If you have any problems with the way your liver works, or any problems with the way your kidneys work.
- If you have either of the following blood disorders: polycythaemia or porphyria.
- If you know you have a type of cancer which is affected by hormones.
- If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
- If you have ever had an allergic reaction to a medicine.
How to take danazol
- Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about danazol, and will also provide you with a full list of side-effects which you could experience from taking it.
- You should start taking danazol on the first day of your next period unless you have been told otherwise.
- Your doctor will tell you how many capsules to take each day, and when you should take them. As a guide, for the treatment of endometriosis or breast pain, danazol is usually taken 2-4 times daily for 3-6 months. Take the capsules exactly as your doctor tells you to. Your dose will be printed on the label of the pack to remind you about what the doctor said to you.
- Swallow the capsules whole with a drink of water - do not chew or open them before you swallow.
- You can take danazol capsules either before or after meals, but try to take your doses at the same times each day, as this will help you to remember to take them regularly.
- If you forget to take a dose, take it as soon as you remember (unless it is nearly time for your next dose, in which case leave out the missed dose). Do not take two doses together to make up for a forgotten dose.
Getting the most from your treatment
- Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. Your doctor may want you to have some blood tests during this treatment.
- It is important that you do not become pregnant while you are on danazol. If appropriate, you and your partner should use a non-hormonal method of contraception, such as a condom. This is because hormonal methods (such as 'the pill' or 'mini pill') will not work. Speak with your doctor if you need further advice about what methods of contraception are suitable for you to use.
- It is best not to drink alcohol while you are on danazol. This is because drinking alcohol while taking danazol could make you feel sick or short of breath.
Can danazol cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones associated with danazol. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.
|Danazol side-effects||What can I do if I experience this?|
|Feeling sick (nausea), stomach pain||Stick to simple foods (avoid rich or spicy meals)|
|Feeling dizzy or tired, eyesight changes||If this happens, do not drive and do not use tools or machines while affected. Let your doctor know about any eyesight changes|
|Headache, other aches and pains||Ask your pharmacist to recommend a suitable painkiller. If the headache is severe or continues, speak with your doctor|
|Increased growth of hair (particularly on your body or face), voice changes, hair loss similar to male baldness||Speak with your doctor about this as soon as possible. An alternative treatment may be more suitable for you|
|Acne, skin rash, muscle cramps, mood changes, changes in your desire for sex, increased appetite and weight changes, irregular menstrual periods, vaginal dryness and irritation, hot flushes, reduced breast size, a feeling that your heart is racing||If any of these become troublesome, speak with your doctor|
Important: if you experience any of the following rare but possibly serious symptoms, please speak with your doctor straightaway:
- A severe headache and sickness (nausea and vomiting).
- Any yellowing of your skin or of the whites of your eyes (jaundice).
- Any painful swelling of your arms or legs, or sudden chest pain.
- Any bruising that you can't explain. This could be a sign of a blood disorder.
If you experience any other symptoms which you think may be due to the capsules, please speak with your doctor or pharmacist for further advice.
How to store danazol
- Keep all medicines out of the reach and sight of children.
- Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.
If you buy any medicines, always check with a pharmacist that they are suitable to take with your other medicines.
If you are due to have an operation or any dental treatment, please tell the person carrying out the treatment which medicines you are taking.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Further reading and references
Manufacturer's PIL, Danol® 100 mg and 200 mg Capsules; Sanofi, The electronic Medicines Compendium. Dated November 2020.
British National Formulary, 82nd Edition (Sep 2021); British Medical Association and Royal Pharmaceutical Society of Great Britain, London.