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Generic name: triptorelin [ TRIP-toe-REL-in ]
Brand names: Trelstar, Triptodur, Trelstar Depot, Trelstar LA, Trelstar LA Mixject, Trelstar Depot Mixject, Trelstar Mixject
Dosage forms: intramuscular powder for injection (11.25 mg/3 months; 22.5 mg/6 months; 3.75 mg/month); intramuscular powder for injection, extended release (22.5 mg)
Drug classes: Gonadotropin releasing hormones, Hormones / antineoplastics

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jun 28, 2022.

What is triptorelin?

Triptorelin is a man-made form of a hormone that regulates many processes in the body.

The Trelstar brand of triptorelin is used in men to treat the symptoms of prostate cancer. Trelstar treats only the symptoms of prostate cancer and does not treat the cancer itself.

The Triptodur brand of triptorelin is used to treat precocious puberty in boys and girls who are at least 2 years old.


Do not use triptorelin if you are pregnant. Use effective birth control, and tell your doctor if you become pregnant during treatment.

Some people using triptorelin have had new or worsening mental problems or seizures (convulsions). Call your doctor right away if you have a seizure, or any unusual changes in mood or behavior (anger, aggression, crying, feeling restless or irritable).

Triptorelin can cause a temporary increase in certain hormones, especially when you first start using this medicine. This may cause side effects that are similar to the condition being treated.

Before taking this medicine

You should not use this medication if you are allergic to triptorelin or similar drugs such as leuprolide (Lupron, Viadur, Eligard) or goserelin (Zoladex).

Do not use triptorelin if you are pregnant. It could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using this medicine.

To make sure triptorelin is safe for you, tell your doctor if you have ever had:

  • heart disease, long QT syndrome or other heart rhythm disorder;

  • a heart attack or stroke;

  • an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);

  • diabetes;

  • epilepsy or other seizure disorder;

  • mental illness; or

  • a tumor or blood vessel problem in your brain.

Ask a doctor if it is safe to breastfeed while using this medicine.

Triptorelin may affect fertility (ability to have children) in men.

How should I use triptorelin?

Take triptorelin exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.

Triptorelin is injected into a muscle. A healthcare provider can teach you how to properly use the medication by yourself.

Triptorelin is usually given once every 4, 12, or 24 weeks. Your dose schedule will depend on the strength and brand of triptorelin you are using.

Triptorelin must be mixed with a liquid (diluent) before using it. When using injections by yourself, be sure you understand how to properly mix and store the medicine.

Triptorelin can increase certain hormones when you first start using this medicine or after each new injection. This may cause symptoms of prostate cancer or precocious puberty to get worse for a short time. These side effects should get better within 1 to 2 months. Call your doctor if your symptoms do not improve, or if they get worse while using triptorelin.

You may need frequent medical tests.

Store at room temperature away from moisture and heat. Do not freeze.

Each vial (bottle) is for one use only. Throw it away after one use, even if there is still medicine left inside.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

Dosing information

Usual Adult Dose for Prostate Cancer:

3.75 mg IM every 4 weeks
11.25 mg IM every 12 weeks
22.5 mg IM every 24 weeks

-Administered as a single IM injection in either buttock; the injection site should be alternated periodically.
-Due to different release characteristics, the dosage strengths are not additive and must be selected based upon the desired dosing schedule.

Use: For the palliative treatment of advanced prostate cancer

Usual Pediatric Dose for Precocious Puberty:

2 years and older:
22.5 mg IM every 24 weeks

Duration of therapy: Therapy should be discontinued at the onset of puberty at the discretion of the physician.

-This drug should only be administered by a healthcare provider.
-Monitor response to this drug with LH levels after a GnRH or GnRH agonist stimulation test, basal LH, or serum concentration of sex steroid levels beginning 1 to 2 months following initiation of therapy, during therapy as necessary to confirm maintenance of efficacy, and with each subsequent dose.
-Measure height (for calculation of growth rate) every 3 to 6 months and monitor bone age periodically.
-Noncompliance with drug regimen or inadequate dosing may result in inadequate control of the pubertal process with gonadotropins and/or sex steroids increasing above prepubertal levels.
-If the dose of this drug is not adequate switching to an alternative GnRH agonist for the treatment of CPP with the ability for dose adjustment may be necessary.

Use: For the treatment of pediatric patients 2 years of age and older with central precocious puberty (CPP)

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose, or if you miss an appointment for your triptorelin injection.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using triptorelin?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Triptorelin side effects

Get emergency medical help if you have signs of an allergic reaction to triptorelin: hives, red skin rash, severe itching, sweating; dizziness, fast heartbeats; trouble breathing or swallowing; swelling of your face, lips, tongue, or throat.

Some people using triptorelin have had new or worsening mental problems or seizures (convulsions). Call your doctor right away if you have a seizure, or any unusual changes in mood or behavior (anger, aggression, crying, feeling restless or irritable).

Triptorelin can cause a temporary increase in certain hormones, especially when you first start using this medicine. This may cause side effects that are similar to the condition being treated. Call your doctor at once if you have:

  • painful or difficult urination, burning when you urinate, blood in the urine;

  • bone pain;

  • (in children) new or worsening signs of puberty;

  • a seizure;

  • chest pain or pressure, pain spreading to your jaw or shoulder;

  • sudden numbness or weakness, slurred speech;

  • increased pressure inside the skull - severe headaches, ringing in your ears, dizziness, nausea, vision problems, pain behind your eyes;

  • loss of movement in any part of your body;

  • high blood sugar - increased thirst, increased urination, hunger, dry mouth, fruity breath odor; or

  • nerve problems - back pain, muscle weakness, problems with balance or coordination, severe numbness or tingling in your legs or feet, loss of bladder or bowel control.

Common triptorelin side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect triptorelin?

Other drugs may interact with triptorelin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Popular FAQ

Trelstar (triptorelin) can be given for prostate cancer as long as it is tolerated and your doctor believes it is still safe and effective for you, which may be many years. Trelstar is intended as a long-term treatment, and despite the inevitable progression to castration-resistant prostate cancer (CRPC) in most patients receiving androgen deprivation therapies (ADT), such as Trelstar, there may still be benefits in continuing ADT in men in addition to introducing other treatment options for CRPC. Continue reading

Triptorelin may be used in advanced prostate cancer to lower levels of testosterone in men. Prostate cancer needs the hormone testosterone to grow. Almost all testosterone in men is made by the testicles. Triptorelin stops the testicles from making testosterone, reducing testosterone levels, and slowing or stopping the growth of cancer cells. This can help relieve symptoms such as painful or difficult urination. Continue reading

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use triptorelin only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.