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Triptorelin: 7 things you should know

Medically reviewed by Carmen Pope, BPharm. Last updated on April 3, 2023.

1. How it works

  • Triptorelin is a man-made form of a hormone that may be used to treat precocious puberty, advanced prostate cancer, and other conditions off-label. A Canadian brand of triptorelin (Decapeptyl) may be used for assisted reproductive technologies (ART) in women undergoing controlled ovarian hyperstimulation.
  • Triptorelin mimics gonadotropin-releasing hormone (GnRH) and is known as an agonist analog of GnRH. GnRH regulates the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH are known as gonadotropins because they stimulate the gonads (the testes in males and the ovaries in females) to release hormones. Triptorelin causes an initial, transient, surge in FSH, LH, testosterone, and estradiol, which through a negative feedback loop is followed by a sustained decrease in FSH and LH and a significant reduction in ovarian and testicular steroidogenesis usually 2 to 4 weeks after initiation. Triptorelin reduces testosterone levels in men, slowing or stopping the growth of cancer cells and relieving symptoms such as painful or difficult urination. When used for ART, triptorelin prevents the premature LH surge in women undergoing controlled ovarian hyperstimulation.
  • Triptorelin belongs to the class of medications known as gonadotropin-releasing hormone agonists.

2. Upsides

  • May be used to treat men with advanced prostate cancer (Trelstar brand).
  • May also be used by boys or girls aged at least 2 years or older to treat central precocious puberty (Triptodur brand)
  • May also be used in women undergoing controlled ovarian hyperstimulation for assisted reproductive technologies (ART) to prevent a premature LH surge (Decapeptyl brand [Canadian product]). Administered by subcutaneous injection into the lower abdomen; alternate injection sites. If a dose is missed, it can be administered on the same day; however, do not double doses.
  • May also be used off-label (not an approved FDA indication) for endometrial stromal sarcoma, endometriosis, and paraphilia/hypersexuality. Recommended by the World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for the Biological Treatment of Paraphilias for paraphilia/hypersexuality.
  • For advanced prostate cancer, Trelstar is given every 4 weeks (3.75mg), 12 weeks (11.25mg), or 24 weeks (22.5mg) depending on the dosage.
  • For central precocious puberty, Triptodur 22.5mg is given by IM injection once every 24 weeks. Treatment should be discontinued at the appropriate age of onset of puberty.
  • When used as adjunctive therapy for ART (off-label), the usual dose of Decapeptyl is 0.1 mg once daily initiated on day 2 or 3 or days 21 to 23 of the menstrual cycle (or 5 to 7 days before the expected onset of menses). Adjust the dose according to the ovarian response as measured by ultrasound with or without serum estradiol levels. Continue treatment until the follicles achieve a suitable size (typically 4 to 7 weeks).
  • Triptorelin causes serum testosterone concentrations to fall to levels typically observed in surgically castrated men.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Hot flashes are the most common side effect reported in men receiving triptorelin for prostate cancer, reported in up to 87% of men. Decreased red blood cells, decreased hemoglobin, headache, increased serum glucose levels, increased liver enzymes (alanine aminotransferase, serum aspartate, and serum transaminases), skeletal pain, increased blood urea nitrogen, edema, high blood pressure, erectile dysfunction, testicular atrophy, infection, impotence, and painful urination.
  • Pain and redness at the injection site is the most common side effect reported by children receiving triptorelin for precocious puberty. Other side effects include nasopharyngitis, gastrointestinal side effects, menstruation, and ear pain.
  • Triptorelin may increase a person's risk of cardiovascular disease, such as a heart attack, stroke, or sudden cardiac death. The risk is higher in those with pre-existing QT prolongation, frequent electrolyte abnormalities, and taking concomitant medications also known to prolong the QT interval. Consider periodic monitoring of electrolytes and ECGs in at-risk people.
  • May increase the risk for osteoporosis and bone fractures particularly with prolonged use and in those with decreased bone density.
  • This initial surge of LH and FSH caused by triptorelin may cause a transient worsening of prostate cancer symptoms such as urethral or bladder outlet obstruction, bone pain, spinal cord injury, and hematuria.
  • The Trelstar and Triptodur brands of triptorelin must be given by IM (intramuscular) injection by a healthcare professional. Dosage varies depending on the brand of triptorelin being given and what it is being used for. Trelstar is recommended to be given into the buttock and Triptodur should be given into the buttock or thigh; alternate injection sites. Administer immediately after reconstitution.
  • The dosage of triptorelin may need to be reduced in liver or kidney disease because studies have shown a two to four-fold higher exposure in these populations compared to healthy young men.
  • When the Decapeptyl brand of triptorelin is used for ART, it should not be used in women who are breastfeeding, or with undiagnosed abnormal vaginal bleeding (when used for endometriosis).
  • When used off-label to treat endometriosis, hormonal add-back therapy (such as estrogens or progestins) is recommended at the start of treatment to reduce bone mineral loss. Use of triptorelin is generally limited to less than 6 or 12 months due to side effects.
  • When used off-label to treat paraphilia/hypersexuality triptorelin may cause an initial increase in androgen concentrations, which may be treated with an antiandrogen such as flutamide or cyproterone for 1 to 2 months. Should not be used in patients with osteoporosis or active pituitary pathology.
  • The Trelstar and Triptodur brands of triptorelin are kept at room temperature before reconstitution (20°C to 25°C [68°F to 77°F]) and should be administered immediately after reconstitution. The Decapeptyl brand should be refrigerated at 2°C to 8°C (36°F to 46°F). Do not freeze and protect from light.
  • Significant drug interactions exist (see interactions, below).
  • Triptorelin may impair fertility in men.
  • Triptorelin may cause harm to a developing baby and should not be given to pregnant women. There are no data on the effects of triptorelin during breastfeeding but there is a potential for serious reactions, so women should be advised not to breastfeed when taking triptorelin.
  • Has been associated with an increased risk of fractures. Warn patients to be careful when moving around.
  • Rarely may cause hypersensitivity reactions including edema of the face, tongue, lip, or throat.
  • Trelstar and Triptodur are not available as a generic.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Triptorelin is a gonadotropin-releasing hormone (GnRH) agonist, that mimics the action of GnRH. After an initial transient surge, it causes a sustained decrease in FSH and LH and a significant reduction in ovarian and testicular steroidogenesis usually 2 to 4 weeks after initiation. It may be used to treat advanced prostate cancer, central precocious puberty, or to prevent a premature LH surge in women undergoing ovarian hyperstimulation for ART. Hot flashes are the main side effect in men with prostate cancer.

5. Tips

  • Seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with triptorelin. Do not take any other medications, including those brought over the counter from a supermarket or drug store without talking to your doctor or pharmacist.
  • Keep your appointments with your healthcare provider so that your triptorelin injection is administered on time. For a man with prostate cancer, low levels of testosterone prevent cancer from growing.
  • You may experience a transient worsening of prostate cancer symptoms such as urethral or bladder outlet obstruction, bone pain, spinal cord injury, and hematuria when you first start triptorelin. This is caused by an initial surge of LH and FSH which subsequently declines.
  • If you have been prescribed the Decapeptyl brand of triptorelin for ART, ask your healthcare provider to show you how to self-administer it, so you can inject yourself at home. When not in use store Decapeptyl in the refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze and protect from light. You can leave it out of the refrigerator for 30 minutes before use to allow it to warm up to room temperature.
  • If you have diabetes, you may need to monitor your blood sugar levels more regularly while being treated with triptorelin.
  • Triptorelin may increase your risk of fracturing a bone. Ensure there are no tripping hazards around your home and be careful when getting out of bed or going up or downstairs.
  • Triptorelin may increase your risk for cardiovascular disease. Ensure you eat a healthy diet, exercise, don't smoke, and take your medications as directed by your doctor for any coexisting conditions, such as high cholesterol or diabetes. If you experience any chest pain or pain that radiates down your arm or up your neck, seek urgent medical attention.
  • See your doctor immediately if you develop any side effects of concern including shortness of breath or difficulty breathing, edema or swelling of the face or throat, sudden headache, vomiting, visual changes, or confusion.
  • Triptorelin may cause impotence and affect your fertility. Talk to your doctor if you are planning to have a family in the future.

6. Response and effectiveness

  • The first administration of triptorelin is followed by a transient surge of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and testosterone. Within 2 to 4 weeks, a sustained decrease in FSH and LH, and a significant reduction of testicular steroidogenesis are usually seen. Serum testosterone levels are reduced to those typically seen in surgically castrated men. Ultimately, tissues and functions that require these hormones become inactive.
  • Research has shown that castration levels of serum testosterone (≤ 1.735 nmol/L; equivalent to 50 ng/dL) were achieved at Day 29 in 91.2% of patients treated with 3.75mg, 97.7% of patients treated with 11.25mg, and 97.5% of patients treated with Trelstar 22.5 mg. Castration was maintained in 93.3% of patients in the period from Day 57 to Day 337 treated with 22.5mg.
  • Serum triptorelin levels did not accumulate throughout treatment.
  • The effects of triptorelin can usually be reversed once the drug is discontinued.
  • Triptorelin is usually continued, often with other medications, even with the development of metastatic prostate cancer.

7. Interactions

Medicines that interact with triptorelin may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with triptorelin. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

There are over 255 medications that have major or moderate interactions with triptorelin. Some common medications that may interact with triptorelin include:

  • acid control treatments such as antacids, famotidine, or omeprazole
  • albuterol
  • antibiotics, such as erythromycin, levofloxacin, or metronidazole
  • anticancer treatments such as doxorubicin or ceritinib
  • antidepressants, such as amitriptyline, citalopram, escitalopram, or venlafaxine
  • antidiarrheal medications, such as loperamide
  • antifungals, such as azithromycin
  • antihistamines, such as hydroxyzine
  • antipsychotics, such as aripiprazole, clozapine, haloperidol, thioridazine, or ziprasidone
  • bisacodyl
  • buprenorphine
  • chloroquine or hydroxychloroquine
  • cisapride
  • droperidol
  • heart medications, such as amiodarone, felodipine, or flecainide
  • HIV medications, such as efavirenz or saquinavir
  • insulin and other antidiabetic medications such as glibenclamide, glyburide, or metformin (triptorelin may increase blood sugar levels)
  • lactulose
  • lithium
  • magnesium salts
  • methadone, oxycodone, and other opiates
  • mineral oil
  • moxifloxacin
  • multiple sclerosis agents such as fingolimod or ozanimod
  • ondansetron
  • oxytocin
  • papaverine
  • pimozide
  • quinidine
  • QT-interval prolonging drugs, such as amiodarone, amisulpride, chlorpromazine, haloperidol, or metoclopramide
  • salmeterol
  • senna
  • tamoxifen
  • tolbutamide
  • tramadol
  • ziprasidone.

Triptorelin can increase the risk of QT prolongation, a potentially life-threatening irregular heart rhythm. Those at higher risk include people with congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (such as magnesium or potassium loss due to severe or prolonged diarrhea or vomiting).

Triptorelin suppresses the pituitary-gonadal system which will affect diagnostic tests of pituitary gonadotropic and gonadal functions conducted during treatment and for eight weeks after discontinuation.

Hyperprolactinemic drugs (such as bromocriptine, lisuride, or metoclopramide) should not be used at the same time as triptorelin since hyperprolactinemia reduces the number of pituitary GnRH receptors.

Note that this list is not all-inclusive and includes only some common medications that may interact with Triptorelin. You should refer to the prescribing information for Triptorelin for a complete list of interactions.


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.

Copyright 1996-2023 Revision date: April 2, 2023.