What is Synarel: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Synarel overview

BRAND NAMES:

  • Synarel

Generic Names:

  • Synarel

Uses:

  • Treats endometriosis and premature puberty.

Therapeutic Classes:

  • Endocrine-Metabolic Agent

Forms:

  • Spray

How it’s taken:

  • Into the nose

What is Synarel used for?

Synarel is a gonadotropin-releasing hormone medication that is used to treat endometriosis and precocious puberty. Synarel works by relieving symptoms caused by both endometriosis and precocious puberty including pelvic pain and abnormal hormone levels.

What form(s) does Synarel come in

  • Spray

What are common Synarel doses?

  • Bottle 8ML of 2MG/ML

Common Synarel prescriptions

  • Synarel
    8ml of 2mg/ml bottle

How to take Synarel

  • For endometriosis: Lean your head forward and put the tip of the bottle into your nostril.Close the other nostril with your finger. Spray the medicine once into your nostril while at the same time sniffing gently.Do not spray this medicine in your other nostril unless your doctor tells you to.Tilt your head backwards for a few seconds after spraying this medicine.You should start using this medicine between the 2nd and 4th day of your menstrual period, unless instructed otherwise by your doctor. This medicine is used for six months.

  • To do this, hold the spray bottle with your thumb on the bottom of the bottle and your index and middle fingers on the 2 flaps on the side of the pump.

  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.

  • Nasal routeAfter using the nasal spray, wipe the tip of the bottle with a clean tissue and put the cap back on.

  • Nasal routeKeep the bottle tightly closed when not using it. Store at room temperature, away from heat and direct light. Keep the bottle upright. Do not freeze. After you prime the bottle, there will only be 60 doses or sprays. Keep track of the number of sprays you use. Throw the bottle away after you use 60 sprays (for 30 days) even if some liquid remains.

  • For premature puberty: Tilt your child's head back slightly. Put the tip of the bottle into your child's nostril.Close the other nostril with your finger and spray the medicine into your child's nostril while at the same time sniffing gently.Allow 30 seconds between sprays in the same nostril.Keep your child's head tilted back for a few seconds after spraying this medicine.

  • To use:

  • Blow your or your child's nose gently to clear the nostrils. You can also use a bulb syringe to clean your child's nose.

  • Take the cap off the bottle and remove the clip from the neck of the pump.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Nasal routeThis medicine is for use only in the nose. Do not get any of it in your eyes or on your skin. If it does get on these areas, rinse it off right away.

  • If you are using the medicine for the first time, you will need to prime the spray pump.

  • Avoid sneezing during or right after using this medicine.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose. It is important to use this medicine regularly without missing doses.

  • Push down with your index and middle fingers. Keep pumping until you see some of the medicine spray from the bottle.

  • For premature puberty: Tilt your child's head back slightly. Put the tip of the bottle into your child's nostril.Close the other nostril with your finger and spray the medicine into your child's nostril while at the same time sniffing gently.Allow 30 seconds between sprays in the same nostril.Keep your child's head tilted back for a few seconds after spraying this medicine.

  • Nasal routeAfter using the nasal spray, wipe the tip of the bottle with a clean tissue and put the cap back on.

  • Nasal routeKeep the bottle tightly closed when not using it. Store at room temperature, away from heat and direct light. Keep the bottle upright. Do not freeze. After you prime the bottle, there will only be 60 doses or sprays. Keep track of the number of sprays you use. Throw the bottle away after you use 60 sprays (for 30 days) even if some liquid remains.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose. It is important to use this medicine regularly without missing doses.

  • Avoid sneezing during or right after using this medicine.

  • Push down with your index and middle fingers. Keep pumping until you see some of the medicine spray from the bottle.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Nasal routeThis medicine is for use only in the nose. Do not get any of it in your eyes or on your skin. If it does get on these areas, rinse it off right away.

  • To use:

  • To do this, hold the spray bottle with your thumb on the bottom of the bottle and your index and middle fingers on the 2 flaps on the side of the pump.

  • For endometriosis: Lean your head forward and put the tip of the bottle into your nostril.Close the other nostril with your finger. Spray the medicine once into your nostril while at the same time sniffing gently.Do not spray this medicine in your other nostril unless your doctor tells you to.Tilt your head backwards for a few seconds after spraying this medicine.You should start using this medicine between the 2nd and 4th day of your menstrual period, unless instructed otherwise by your doctor. This medicine is used for six months.

  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.

  • Take the cap off the bottle and remove the clip from the neck of the pump.

  • If you are using the medicine for the first time, you will need to prime the spray pump.

  • Blow your or your child's nose gently to clear the nostrils. You can also use a bulb syringe to clean your child's nose.

What to do if you miss a dose of Synarel

  • Use your medicine as soon as possible unless it is almost time for your next dose.

  • Skip the missed dose if it is almost time for your next regular dose.

  • Do not use two doses at the same time.

Synarel contraindications

  • This medicine is not right for everyone. You should not use it if you had an allergic reaction to nafarelin, gonadotropin releasing hormone, or similar medicines, or if you have unusual vaginal bleeding, are pregnant, or breastfeeding.

Synarel warnings

  • Women: Your menstrual periods should stop, but you might have light bleeding or spotting. If you continue to have a period after taking this medicine for more than a month, call your doctor.

  • If you get a stuffy nose, and need to use a nasal decongestant, call your doctor. If your doctor tells you to use a decongestant, wait at least 2 hours after using nafarelin to use the decongestant.

  • You should not get pregnant while using this medicine to treat endometriosis. Talk to your doctor about effective methods of birth control to use. If you do get pregnant, tell your doctor right away.

  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.

  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.

  • This medicine may cause the following problems:Changes in mood or behaviorIncreased risk for seizuresCysts in the ovariesWeaker bones, which may lead to osteoporosis

  • It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant. Use an effective form of birth control to keep from getting pregnant during treatment with this medicine.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • Women: Your menstrual periods should stop but you might have light bleeding or spotting. If you continue to have a period after taking this medicine for more than a month, call your doctor.

  • Tell your doctor if you have polycystic ovarian disease, rhinitis (stuffy or runny nose), or a history of depression, mental illness, seizures, brain tumor, or osteoporosis. Tell your doctor if you smoke or drink alcohol.

  • Your symptoms might get worse when you first start using this medicine, but they should get better as the medicine starts to work. If your condition does not begin to improve after using this medicine for 2 months, check with your doctor.

Synarel interactions

  • You should not get pregnant while using this medicine to treat endometriosis. Talk to your doctor about effective methods of birth control to use. If you do get pregnant, tell your doctor right away.

  • If you get a stuffy nose, and need to use a nasal decongestant, call your doctor. If your doctor tells you to use a decongestant, wait at least 2 hours after using nafarelin to use the decongestant.

  • If you are using this medicine to treat endometriosis, you should stop having menstrual periods. If you have a period after taking this medicine for more than a month, call your doctor.

  • Make sure your doctor knows if you have a family history of osteoporosis if you are being treated for endometriosis.

  • Tell your doctor if you have used alcohol or tobacco for a long time.

  • Some medicines can affect how nafarelin works. Tell your doctor if you are using medicines to treat depression (including bupropion), seizure medicines, or steroids.

Synarel side effects

Serious Side Effects

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Bloating, stomach discomfort, pain, or heaviness

  • Depression, mood, or behavior changes

  • Heavy vaginal bleeding

  • Seizures

  • Unusual or severe bone or back pain

  • Loss of interest in sex (during endometriosis treatment)

  • Mood changes

  • Weight gain or fluid retention (during endometriosis treatment)

Less Serious Side Effects

  • Irritation of the nostrils

  • Changes in breast size

  • Weight gain or fluid retention (during endometriosis treatment)

  • Dryness of vagina

  • Loss of interest in sex

  • Warmth or redness in your face, neck, arms, or upper chest

  • Headache, muscle aches

  • Acne, skin rash, flaking

  • Weight gain or fluid retention

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