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Trelstar Side Effects

Generic Name: triptorelin

Note: This document contains side effect information about triptorelin. Some of the dosage forms listed on this page may not apply to the brand name Trelstar.

In Summary

More frequent side effects include: diabetes mellitus and hyperglycemia. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to triptorelin: intramuscular powder for suspension, intramuscular powder for suspension 6 month

Along with its needed effects, triptorelin (the active ingredient contained in Trelstar) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking triptorelin:

More commonFor children Less commonFor children
  • Anxiety
  • body aches or pain
  • chills
  • cough
  • cough producing mucus
  • difficulty with breathing
  • ear congestion
  • fever
  • general feeling of discomfort or illness
  • headache
  • joint pain
  • loss of voice
  • mood or mental changes, including abnormal crying, aggression, agitation, delusions, irritability, nervousness, or restlessness
  • muscle aches and pains
  • nasal congestion
  • runny nose
  • shivering
  • sneezing
  • sore throat
  • sweating
  • tightness in the chest
  • trouble sleeping
  • unusual tiredness or weakness
  • vomiting
For adult men
  • Bladder pain
  • bloating or swelling of the face, arms, hands, lower legs, or feet
  • bloody or cloudy urine
  • blurred vision
  • chest pain
  • cough producing mucus
  • decrease in urine volume or frequency of urination
  • difficult or labored breathing
  • difficult, burning, or painful urination
  • difficulty in passing urine
  • dizziness
  • dry mouth
  • flushed, dry skin
  • frequent urge to urinate
  • fruit-like breath odor
  • headache
  • increased hunger
  • increased thirst
  • increased urination
  • loss of consciousness
  • lower back or side pain
  • nausea
  • nervousness
  • pale skin
  • pounding in the ears
  • rapid weight gain
  • slow or fast heartbeat
  • stomach ache
  • sweating
  • tightness in the chest
  • tingling of the hands or feet
  • troubled breathing
  • troubled breathing with exertion
  • unexplained weight loss
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • unusual weight gain or loss
  • vomiting
Incidence not knownFor children
  • Blurred or loss of vision
  • depression
  • difficulty with swallowing
  • disturbed color perception
  • dizziness
  • double vision
  • halos around lights
  • hives, itching, skin rash
  • nervousness
  • night blindness
  • overbright appearance of lights
  • pounding in the ears
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • seizures
  • slow or fast heartbeat
  • thoughts of killing oneself
For adult men
  • Anxiety
  • changes in skin color
  • changes in vision
  • chest discomfort
  • cold, clammy, or pale skin
  • confusion
  • dizziness or lightheadedness
  • fainting
  • inability to speak
  • irregular heartbeat
  • numbness or tingling in the face, arms, or legs
  • pain
  • pain or discomfort in the arms, jaw, back, or neck
  • pain, redness, or swelling in the arm or leg
  • seizures
  • severe or sudden headache
  • slow heart rate
  • slurred speech
  • sudden shortness of breath or troubled breathing
  • temporary blindness
  • tenderness
  • trouble speaking, thinking, or walking
  • weakness in the arm or leg on one side of the body, sudden and severe

Some side effects of triptorelin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More commonFor children
  • Bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • stuffy or runny nose
For adult men
  • Bone pain
  • chills
  • decrease in testicle size
  • decreased interest in sexual intercourse
  • diarrhea
  • feeling of warmth or redness of the face, neck, arms, and occasionally, upper chest
  • fever
  • general feeling of discomfort or illness
  • inability to have or keep an erection
  • joint pain
  • leg pain
  • loss in sexual ability, desire, drive, or performance
  • loss of appetite
  • muscle aches and pains
  • redness of the face, neck, arms, and occasionally, upper chest
  • runny nose
  • shivering
  • sore throat
  • sudden sweating
  • trouble sleeping
Less commonFor children
  • Change in hearing
  • dryness or soreness of the throat
  • ear drainage
  • earache
  • hoarseness
  • itching of the ears
  • pain or tenderness around the eyes and cheekbones
  • tender, swollen glands in the neck
  • voice changes
For adult men
  • Back pain
  • belching
  • body aches or pain
  • breast pain
  • burning, dry, or itching eyes
  • congestion
  • crying
  • depersonalization
  • difficulty having a bowel movement
  • difficulty with moving
  • discharge or excessive tearing
  • dysphoria
  • euphoria
  • eye pain
  • heartburn
  • hoarseness
  • indigestion
  • injection site pain
  • itching or rash
  • lack or loss of strength
  • leg cramps
  • loss of appetite
  • muscle aching or cramping
  • muscle pains or stiffness
  • paranoia
  • quick to react or overreact emotionally
  • rapidly changing moods
  • redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
  • runny nose
  • stomach discomfort, upset, or pain
  • swelling of the breasts or breast soreness in both females and males
  • swollen joints
  • tender, swollen glands in the neck
  • trouble swallowing
  • voice changes
  • weight loss

For Healthcare Professionals

Applies to triptorelin: intramuscular powder for injection, intramuscular powder for injection extended release


The most common adverse events were hot flushes, impotence, decreased libido, skeletal pain, and headache.[Ref]


Very common (10% or more): Hot flush (up to 73%), hypertension (14.2%)
Common (1% to 10%): Dependent edema
Uncommon (0.1% to 1%): Embolism
Rare (less than 0.1%): Hypotension
Postmarketing reports: Blood pressure increased, thromboembolic events including, but not limited to, pulmonary emboli, cerebrovascular accident, myocardial infarction, deep venous thrombosis, transient ischemic attack, and thrombophlebitis[Ref]


Very common (10% or more): Impotence (30 to 40%), urinary tract infection (11.6%), erectile dysfunction (10%), dysuria; women: dyspareunia, dysmenorrhea, ovarian hyperstimulation syndrome, ovarian hypertrophy, pelvic pain, vulvovaginal dryness, bleeding/spotting, genital hemorrhage (including menorrhagia and metrorrhagia)
Common (1% to 10%): Testicular atrophy, breast pain, gynecomastia, urinary retention, vaginal bleeding (children)
Uncommon (0.1% to 1%): Testicular pain, vaginal discharge (children)
Rare (less than 0.1%): Ejaculation failure
Frequency not reported: Testosterone levels increased, testosterone levels decreased, worsening of urethral or bladder outlet obstruction, worsening of symptoms of endometriosis
Postmarketing reports: Amenorrhea[Ref]

At the beginning of treatment, endometriosis symptoms including pelvic pain and dysmenorrhea are commonly exacerbated due to an initial transient increase in plasma estradiol levels. These symptoms are transient and usually disappear in one to two weeks.[Ref]


Very common (10% or more): Decreased libido (30 to 40%), sleep disorders, mood changes
Common (1% to 10%): Insomnia, emotional lability, loss of libido, depression, depressed mood, irritability
Rare (less than 0.1%): Confusional state, decreased activity, euphoric mood
Postmarketing reports: Anxiety, affect lability, nervousness[Ref]


Very common (10% or more): Decreased hemoglobin, decreased red blood count
Common (1% to 10%): Anemia
Frequency not reported: Increased lymphocyte count[Ref]


Very common (10% or more): Increased AST, increased ALT, increased alkaline phosphatase, increased hepatic transaminases
Common (1% to 10%): Abnormal hepatic function
Uncommon (0.1% to 1%): Gama-glutamyl transferase increased
Rare (less than 0.1%): Blood alkaline phosphatase increased[Ref]


Very common (10% or more): Increased glucose
Common (1% to 10%): Diabetes mellitus/hyperglycemia, anorexia
Uncommon (0.1% to 1%): Weight increased, gout, increased appetite, weight decreased[Ref]


Very common (10% or more): Increased BUN
Uncommon (0.1% to 1%): Blood creatinine increased
Frequency not reported: Worsening hematuria, decreased kidney function[Ref]


Very common (10% or more): Influenza (15.8%)
Common (1% to 10%): Bronchitis, coughing, dyspnea, pharyngitis
Uncommon (0.1% to 1%): Asthma aggravated
Rare (less than 0.1%): Orthopnea, epistaxis, nasopharyngitis[Ref]


Very common (10% or more): Skeletal pain (13.2%), back pain (10.8%)
Common (1% to 10%): Pain in extremity, arthralgia, edema in legs, leg cramps, myalgia, musculoskeletal pain, muscle spasms
Uncommon (0.1% to 1%): Muscle cramp, muscular weakness
Rare (less than 0.1%): Joint stiffness, joint swelling, musculoskeletal stiffness, osteoarthritis
Frequency not reported: Worsening of bone pain, increased bone loss, osteoporosis, bone fracture, bone disorder, epiphysiolysis, slipped capital femoral epiphysis
Postmarketing reports: Bone pain[Ref]

Nervous system

Very common (10% or more): Paresthesia in lower limbs
Common (1% to 10%): Headache, dizziness, fatigue
Uncommon (0.1% to 1%): Tinnitus, somnolence, paresthesia
Rare (less than 0.1%): Vertigo, dysstasia, memory impairment
Frequency not reported: Worsening of neuropathy, spinal cord compression with weakness or paralysis of the lower extremities
Postmarketing reports: Convulsions[Ref]


Very common (10% or more): Asthenia
Common (1% to 10%): Leg pain, peripheral edema, leg pain, back pain, fatigue, chest pain, edema
Uncommon (0.1% to 1%): Lethargy, pain, rigors, blood lactate dehydrogenase increased, blood cholesterol increased
Rare (less than 0.1%): Pyrexia, influenza like illness, body temperature increased
Frequency not reported: Chills
Postmarketing reports: Malaise[Ref]


Very common (10% or more): Hyperhidrosis
Common (1% to 10%): Rash, pruritus
Uncommon (0.1% to 1%): Acne, alopecia, hypotrichosis
Rare (less than 0.1%): Purpura, blister
Postmarketing reports: Angioneurotic edema, urticaria[Ref]


Common (1% to 10%): Hypersensitivity reaction
Uncommon (0.1% to 1%): Allergic reactions
Rare (less than 0.1%): Anaphylactic reaction, hypersensitivity
Frequency not reported: Anaphylactic shock, angioedema[Ref]


Common (1% to 10%): Injection site pain, injection site reactions, injection site erythema, injection site inflammation[Ref]


Common (1% to 10%): Nausea, vomiting, constipation, dyspepsia, diarrhea, abdominal pain, abdominal discomfort
Uncommon (0.1% to 1%): Abdominal pain upper, dry mouth
Rare (less than 0.1%): Abdominal distension, dysgeusia, flatulence
Frequency not reported: Gastralgia[Ref]


Common (1% to 10%): Eye pain, conjunctivitis
Rare (less than 0.1%): Abnormal sensation in eye, visual disturbance
Postmarketing reports: Vision blurred[Ref]


Frequency not reported: Tumor flare, exacerbation of disease symptoms
Postmarketing reports: Pituitary adenoma[Ref]

Tumor flare occurred in 5% or less of patients, usually manifested by an increase in urinary symptoms and metastatic pain.[Ref]


Postmarketing reports: Pituitary apoplexy[Ref]

The majority of pituitary apoplexy cases occurred within 2 weeks of the first dose, some within the first hour. In these cases, pituitary apoplexy presented as sudden headache, vomiting, visual changes, ophthalmoplegia, altered mental status, and sometimes cardiovascular collapse. Immediate medical attention has been required.[Ref]


1. "Product Information. Trelstar (triptorelin)" Pharmacia and Upjohn, Kalamazoo, MI.

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Cerner Multum, Inc. "Australian Product Information." O 0

Some side effects of Trelstar may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.