Nafarelin nasal spray Synarel

Last updated by Peer reviewed by Sid Dajani
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Nafarelin spray stops the production of naturally occurring female sex hormones.

Your doctor will tell you how often to use it.

If you sneeze straight after using the spray, you may need to repeat the dose.

Side-effects may occur, although not everyone experiences them. Common side-effects are similar to menopausal symptoms - such as hot flushes, sweating, and weight changes.

Type of medicineGonadorelin analogue
Used forAs part of a fertility programme; and endometriosis
Also calledSynarel®
Available asA nasal spray

Nafarelin is prescribed for women only. It is a synthetic form of a hormone which occurs naturally in women.

If you have been prescribed nafarelin as part of a fertility treatment, it acts on the pituitary gland in your brain to stop the production of natural hormones which control the release of eggs from your ovaries. It does this over a period of time. After this time, you will then be prescribed other hormone treatments to stimulate ovulation.

Nafarelin is also used to treat endometriosis. 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. Nafarelin reduces the production of female sex hormones (such as oestrogen) by its action on your pituitary gland. Oestrogen can worsen certain problems such as endometriosis, so by reducing oestrogen levels, nafarelin will help to ease your symptoms.

Nafarelin is a medicine that cannot be taken in the usual way by mouth (as a tablet). Instead, it is given as a nasal spray because this gets the medicine into your bloodstream.

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking nafarelin it is important that your doctor or pharmacist knows:

  • If you are pregnant or breastfeeding.
  • If you have had any bleeding from your vagina that you do not think is related to your periods.
  • If you have a bone disease such as osteoporosis.
  • 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.
  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about nafarelin spray, and a full list of side-effects which you may experience from using it.
  • Your doctor will tell you how many sprays to use, and whether you should use it in one or both nostrils. This will depend upon the reason why you are using it, so follow the instructions you are given. If you are unsure about how or when to use the spray, ask your pharmacist to explain it to you again.
  • You will be asked to start using the spray on a set day - this is often (but not always) day two of your menstrual cycle.
  • It is important that you use this medicine regularly and space the doses out evenly throughout the day.
  • If you sneeze straight after using the spray, the medicine may not be absorbed and work as it should. If this happens, repeat your dose.
  • If you forget a dose, take it as soon as you remember unless it is almost time for your next dose; in which case, skip the missed dose and take your next dose when it is due. Do not take two doses together to make up for a forgotten dose.

How to use the spray

  1. Read the instructions in the manufacturer's printed leaflet that comes with your medicine.
  2. Remove the plastic cap, and the safety clip under the nozzle.
  3. Before you use the spray for the first time, you must 'prime' the pump. This is so you get the right amount of medicine in each spray. Hold the bottle so that the nozzle is between two fingers, and your thumb is on the bottom of the bottle. Then aim the nozzle away from you and press your thumb upwards several times until a fine spray appears. You only need to do this the first time you use a new bottle.
  4. Then, gently blow your nose to clear it. Do not be too concerned if you have a cold, as the medicine will still be absorbed. Bend your head forward a little, and put the nozzle into one of your nostrils. Hold your other nostril closed with a finger.
  5. Breathe in through your open nostril and at the same time press the bottle once to release a spray. Try to aim the spray towards the back and outer side of your nostril.
  6. Remove the spray and bend your head backwards for a few seconds to allow the spray to spread over the back of your nose.
  7. If you have been told to use the spray in both nostrils at the same time of day, repeat steps 3 and 4 in your other nostril. If not, next time you use the spray, remember to use it in your other nostril.
  8. Clean the nozzle by holding it under warm running water and gently wiping with your finger. It is important to do this before and after every use of the spray to prevent the nozzle from becoming blocked.
  9. Wipe the nozzle with a clean tissue and replace the plastic cap and clip.
  • Keep your appointments with your doctor so that your progress can be monitored.
  • You may notice your symptoms become worse when you first start treatment with nafarelin for endometriosis. This can often be the case, but your symptoms should ease after a couple of weeks.
  • Even if you get a cold or your nose feels blocked, you should continue to use the spray, as it will still work. If you are using any other nasal sprays (such as decongestants), you should use nafarelin spray first, then wait at least 30 minutes after using it before you use any other nasal spray.
  • If you are being treated for endometriosis, you 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.

Along with their useful effects, all medicines can cause unwanted side-effects although not everyone experiences them. The table below lists some of the most common ones associated with nafarelin nasal spray. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve over the first few days of taking a new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common nafarelin side-effectsWhat can I do if I experience this?
Headache, and muscle achesDrink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, speak with your doctor
Nose irritation, nosebleedsIf this becomes troublesome, speak with your doctor
Menopausal symptoms such as hot flushes, dry vagina, increased sweating, reduced interest in sexIf any of these become troublesome, speak with your doctor
Acne, changes in your weight, feeling nervous or emotional, disturbed sleepIf any of these become troublesome, speak with your doctor

Important: if you get a skin rash or redness, or have any difficulties with breathing, you should contact your doctor for advice straightaway. These are rare but possibly serious symptoms, as they may be signs of an allergic reaction to the medicine.

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.

If you buy any medicines check with a pharmacist that they are safe to take with your other 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. Take the container with you, even if it is empty.

If you are having an operation or dental treatment, 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.

Never 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.

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Further reading and references

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