Eligard (Leuprorelin)
GnRH Agonist for Hormone-Dependent Prostate Cancer
Eligard is a prescription injectable medication containing leuprorelin acetate (also known as leuprolide), a gonadotropin-releasing hormone (GnRH) agonist. It is used for the treatment of advanced hormone-dependent prostate cancer in adult men. By suppressing testosterone production, Eligard slows or halts the growth of prostate cancer cells. It is administered as a subcutaneous depot injection at intervals of one, three, or six months depending on the formulation.
Quick Facts
Key Takeaways
- Eligard is a GnRH agonist that lowers testosterone to castrate levels, used primarily for hormone-dependent advanced prostate cancer.
- An initial testosterone surge (“flare”) occurs in the first 1–2 weeks; anti-androgen co-treatment may be used to mitigate symptom worsening.
- The most common side effect is hot flashes, affecting about 58% of patients; other effects relate to testosterone suppression.
- Eligard may increase the risk of cardiovascular events, QT prolongation, bone density loss, and depression—regular monitoring is recommended.
- The injection must be prepared and administered by a healthcare professional; it is stored refrigerated and brought to room temperature before use.
What Is Eligard and What Is It Used For?
Eligard contains leuprorelin acetate, a synthetic GnRH agonist that suppresses testosterone production. It is indicated for the treatment of hormone-dependent metastatic prostate cancer and high-risk non-metastatic prostate cancer in combination with radiation therapy.
The active substance in Eligard belongs to the pharmacological group of gonadotropin-releasing hormone (GnRH) agonists. These medications work by first stimulating and then suppressing the body's production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland. This ultimately leads to a dramatic reduction in testosterone levels, achieving what is known as “medical castration.”
Prostate cancer is one of the most common cancers in men worldwide, with the majority of cases being hormone-dependent—meaning the cancer cells require testosterone to grow. By reducing circulating testosterone to very low levels (below 50 ng/dL, equivalent to surgical castration), Eligard effectively removes the hormonal fuel that drives tumour growth. This approach, known as androgen deprivation therapy (ADT), has been a cornerstone of advanced prostate cancer treatment since the pioneering work of Charles Huggins in the 1940s.
Eligard is specifically indicated for:
- Metastatic hormone-dependent prostate cancer in adult men, where the cancer has spread beyond the prostate gland
- High-risk non-metastatic hormone-dependent prostate cancer in combination with radiation therapy, where aggressive treatment is warranted despite the cancer being localized
According to the European Association of Urology (EAU) 2024 guidelines, GnRH agonists like leuprorelin remain first-line options for androgen deprivation therapy. The choice between GnRH agonists and GnRH antagonists depends on individual patient factors, including cardiovascular risk profile and the clinical urgency of achieving testosterone suppression.
How Does Eligard Work?
After subcutaneous injection, the depot formulation slowly releases leuprorelin acetate into the bloodstream over the prescribed interval. In the first few days, the drug stimulates GnRH receptors in the pituitary gland, causing a temporary surge in LH, FSH, and consequently testosterone. This is known as the “flare” phenomenon. However, with continuous exposure to the GnRH agonist, the pituitary receptors become downregulated and desensitized. By approximately 2–4 weeks after the initial injection, testosterone levels fall to castrate levels and remain suppressed for the duration of treatment.
The depot technology used in Eligard consists of a biodegradable polymer matrix (poly DL-lactide-co-glycolide, or PLGH) dissolved in a biocompatible solvent (N-methyl-2-pyrrolidone). Upon injection under the skin, the solvent dissipates and the polymer solidifies, forming an in-situ depot that releases leuprorelin at a controlled rate. This technology allows for dosing intervals ranging from one month (7.5 mg) to six months (45 mg), depending on the formulation chosen.
What Should You Know Before Taking Eligard?
Eligard is contraindicated in women, children, and patients who have undergone surgical castration. Special monitoring is required for patients with cardiovascular conditions, diabetes, or risk factors for bone loss.
Contraindications
Do not use Eligard if any of the following apply:
- You are a woman or a child—this medication is intended for adult male patients only
- You are hypersensitive (allergic) to leuprorelin acetate, to substances with similar action to the natural GnRH hormone, or to any of the other ingredients
- You have had both testicles surgically removed (bilateral orchiectomy), as Eligard would have no additional effect
- You have symptoms of spinal cord compression or a spinal tumour and Eligard would be used as the sole treatment—in such cases, additional medications must be co-administered
Warnings and Precautions
Talk to your doctor before using Eligard if you have any of the following conditions, as additional monitoring or precautions may be necessary:
Cardiovascular Risk
Patients with pre-existing cardiovascular disease, including heart rhythm disorders (arrhythmias), or those taking medications for these conditions face an elevated risk. GnRH agonist therapy has been associated with QT prolongation on ECG, which can predispose to serious cardiac arrhythmias. Your doctor should assess your cardiovascular risk before and during treatment, including monitoring electrolytes and performing ECGs as appropriate.
Initial Testosterone Flare
During the first week of treatment, testosterone levels typically rise temporarily before falling. This “flare” can worsen existing symptoms, including bone pain, urinary obstruction, spinal cord compression, and haematuria (blood in urine). Your doctor may prescribe an anti-androgen (such as bicalutamide or cyproterone acetate) starting a few days before and continuing for the first few weeks of Eligard treatment to counteract this effect.
Urinary difficulties: If you experience difficulty urinating, you should be monitored more frequently during the first weeks of treatment. Severe cases of ureteral obstruction and spinal cord compression have been reported with GnRH agonist therapy, which may contribute to paralysis if not treated promptly.
Pituitary apoplexy: In rare cases, patients receiving GnRH agonists have experienced pituitary apoplexy (sudden bleeding into or death of the pituitary gland), typically within the first two weeks of treatment. Symptoms include sudden severe headache, vomiting, altered mental status, and sometimes cardiovascular collapse. Seek immediate medical attention if these occur.
Diabetes mellitus: If you have diabetes or impaired glucose tolerance, your blood sugar levels should be monitored regularly during treatment, as GnRH agonists may affect glucose metabolism and insulin resistance.
Bone health: Long-term androgen deprivation therapy increases the risk of osteoporosis and bone fractures. Bone density monitoring (DEXA scans) is recommended, along with adequate calcium and vitamin D supplementation. Weight-bearing exercise should also be encouraged. The EAU guidelines recommend baseline and periodic bone density assessments for patients on long-term ADT.
Depression and mood changes: Depression has been reported in patients receiving Eligard. Inform your doctor if you develop feelings of persistent sadness, hopelessness, or loss of interest during treatment. Psychological support and monitoring should be offered to at-risk patients.
Seizures: Convulsions have been reported in patients taking leuprorelin. If you experience seizures during treatment, notify your doctor immediately.
Intracranial hypertension: Severe or recurrent headache, visual problems, and ringing or buzzing in the ears may indicate idiopathic intracranial hypertension. Contact your doctor immediately if these symptoms occur.
Serious skin reactions: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported rarely with leuprorelin. Stop treatment and seek urgent medical care if you develop widespread skin rash with blisters, mouth ulcers, or peeling skin, especially if preceded by fever and flu-like symptoms.
Pregnancy and Breastfeeding
Eligard is not intended for use in women. It is exclusively indicated for adult male patients with prostate cancer. Women who are pregnant or may become pregnant should not handle the prepared solution, as leuprorelin may be harmful to the developing foetus.
Driving and Operating Machinery
Fatigue, dizziness, and visual disturbances are possible side effects of Eligard treatment, or may result from the underlying disease. If you experience these effects, exercise caution when driving or operating machinery. You are responsible for assessing your own fitness to drive or perform tasks requiring alertness.
How Does Eligard Interact with Other Drugs?
Eligard can interact with medications that prolong the QT interval on ECG. These include certain antiarrhythmics, antibiotics, opioids, and antipsychotics. Always inform your doctor of all medications you are taking.
The primary concern with Eligard drug interactions relates to its potential to prolong the QT interval on the electrocardiogram. When combined with other QT-prolonging agents, the risk of serious cardiac arrhythmias—including the potentially fatal torsades de pointes—is increased. Your prescribing physician should carefully evaluate your current medication list and consider ECG monitoring when Eligard is used alongside these agents.
Major Interactions
| Drug / Drug Class | Risk | Recommendation |
|---|---|---|
| Amiodarone, sotalol | Additive QT prolongation; risk of torsades de pointes | ECG monitoring; consider alternative if possible |
| Quinidine, procainamide | Class IA antiarrhythmics with QT-prolonging effects | Avoid combination or monitor ECG closely |
| Methadone | Known QT prolongation risk; additive with Eligard | ECG monitoring recommended |
| Moxifloxacin | Fluoroquinolone antibiotic with QT-prolonging potential | Use alternative antibiotic if available |
| Antipsychotics (e.g., haloperidol, quetiapine) | Many antipsychotics prolong QT interval | Monitor ECG and electrolytes regularly |
Minor Interactions and Considerations
| Drug / Drug Class | Effect | Recommendation |
|---|---|---|
| Anti-androgens (bicalutamide, enzalutamide) | Often co-administered; additive testosterone suppression | Monitor as part of combined androgen blockade |
| Diabetes medications (insulin, metformin) | ADT may impair glucose tolerance | More frequent blood sugar monitoring |
| Corticosteroids (dexamethasone, prednisone) | Additive bone density loss with long-term use | Consider bone-protective agents |
Always tell your doctor or pharmacist about all medicines you are currently using, including prescription drugs, over-the-counter products, and herbal supplements. Some drug interactions may not be immediately apparent and require careful pharmacological assessment.
What Is the Correct Dosage of Eligard?
Eligard is available in four depot formulations providing 1-month, 3-month, or 6-month dosing intervals. It is always administered by a healthcare professional as a subcutaneous injection.
Eligard should always be used exactly as prescribed by your doctor. The choice of formulation depends on your treatment plan and how often you and your doctor prefer the injection visits. All formulations achieve the same therapeutic goal of sustained testosterone suppression to castrate levels.
Adults
Eligard 7.5 mg – Monthly Depot
One subcutaneous injection of 7.5 mg once every month (every 28–33 days). This is the most common formulation and provides continuous leuprorelin release for approximately 30 days.
Eligard 22.5 mg – 3-Month Depot
One subcutaneous injection of 22.5 mg once every three months (every 84–98 days). Preferred by patients who wish to reduce the frequency of clinic visits.
Eligard 45 mg – 6-Month Depot
One subcutaneous injection of 45 mg once every six months (every 168–196 days). Offers the longest interval between injections and is suitable for patients with stable disease on long-term ADT.
| Formulation | Dose | Injection Interval | Route |
|---|---|---|---|
| Eligard Monthly | 7.5 mg | Every 1 month | Subcutaneous |
| Eligard 3-Month | 22.5 mg | Every 3 months | Subcutaneous |
| Eligard 6-Month | 45 mg | Every 6 months | Subcutaneous |
Children
Eligard is not indicated for use in children. This medication is exclusively for adult male patients with prostate cancer.
Elderly
No dose adjustment is required for elderly patients. The majority of men diagnosed with prostate cancer are over 65 years of age, and Eligard has been widely studied in this population. However, elderly patients should be monitored more closely for cardiovascular events, bone density loss, and metabolic changes, as these risks increase with age and are compounded by testosterone suppression.
Administration
Eligard must be prepared and administered by a healthcare professional (doctor or nurse). The two-syringe system requires proper mixing immediately before injection. The prepared solution is injected subcutaneously (under the skin), typically in the abdomen. The injection site should be varied with each administration. Intra-arterial or intravenous injection must be strictly avoided.
Monitoring During Treatment
Your doctor will monitor your response to treatment through regular blood tests, including testosterone levels and prostate-specific antigen (PSA). PSA is a marker of prostate cancer activity. Successful treatment typically results in falling PSA levels and testosterone suppression below 50 ng/dL (1.7 nmol/L). A rising PSA during treatment may indicate castration-resistant disease and requires further evaluation.
Missed Dose
If you believe your scheduled injection has been missed, contact your doctor as soon as possible. It is important not to extend the interval between injections beyond the recommended time frame, as this may allow testosterone levels to rise and potentially compromise treatment efficacy. Your doctor will arrange the next injection promptly and may check your testosterone level to confirm suppression has been maintained.
Overdose
Since Eligard is administered exclusively by healthcare professionals, overdose is unlikely. In the event that a larger dose than intended is given, your doctor will monitor you closely and provide supportive treatment as needed. There is no specific antidote for leuprorelin overdose, but the clinical effects would be an exaggerated version of the expected pharmacological action.
Stopping Treatment
Prostate cancer generally requires long-term hormonal treatment. Do not stop Eligard treatment even if you feel better or your symptoms improve, unless your doctor specifically advises you to do so. Premature discontinuation may lead to a rise in testosterone levels and potential disease progression. Intermittent androgen deprivation (planned treatment breaks) may be discussed with your oncologist in select cases, but this should only be done under close medical supervision with regular PSA monitoring.
What Are the Side Effects of Eligard?
The most common side effects are hot flashes (affecting ~58% of patients), fatigue, and injection site reactions. Most side effects are related to testosterone suppression. Serious but rare effects include cardiovascular events, bone fractures, and severe skin reactions.
Like all medicines, Eligard can cause side effects, although not everybody gets them. The side effects experienced with Eligard are primarily caused by the hormonal changes resulting from testosterone suppression. Understanding these effects and their frequency can help you and your doctor manage treatment effectively.
Initial Treatment Period
During the first few weeks of Eligard treatment, testosterone levels temporarily rise before falling to castrate levels. This “flare” can cause a transient worsening of cancer-related symptoms, including increased bone pain, urinary difficulties, spinal cord compression, and blood in the urine. Your doctor may prescribe an anti-androgen medication at the start of treatment to counteract these effects. The flare phenomenon does not occur with subsequent injections once testosterone suppression has been established.
Side Effects by Frequency
Very Common
May affect more than 1 in 10 patients
- Hot flashes (approximately 58% of patients)
- Bruising, skin reddening (ecchymosis, erythema)
- Fatigue and general weakness
- Injection site reactions (burning, stinging, redness, induration)
Common
May affect up to 1 in 10 patients
- Upper respiratory tract symptoms (nasopharyngitis)
- Nausea, malaise, diarrhoea, gastroenteritis
- Itching, night sweats
- Joint pain (arthralgia)
- Urinary frequency, urgency, nocturia, difficulty starting urination, painful urination, reduced urine output
- Breast tenderness and enlargement (gynaecomastia), testicular atrophy, testicular pain, erectile dysfunction, decreased penis size, infertility
- Rigors (chills with fever), weakness
- Prolonged bleeding time, changes in blood counts, anaemia
Uncommon
May affect up to 1 in 100 patients
- Urinary tract infections, local skin infections
- Worsening of diabetes
- Abnormal dreams, depression, decreased libido
- Dizziness, headache, altered sensation (paraesthesia), insomnia, altered taste and smell
- Hypertension, hypotension
- Shortness of breath (dyspnoea)
- Constipation, dry mouth, indigestion, vomiting
- Clammy skin, increased sweating
- Back pain, muscle cramps
- Blood in urine (haematuria), bladder spasms, urinary incontinence, urinary retention
- Lethargy, pain, fever, weight gain
- Balance problems, vertigo
- Muscle wasting (after prolonged use)
Rare and Very Rare
May affect fewer than 1 in 1,000 patients
- Abnormal involuntary movements
- Loss of consciousness, syncope (fainting)
- Flatulence, belching
- Hair loss (alopecia), skin rash (acneiform)
- Chest pain
- Injection site ulceration or tissue necrosis (very rare)
- QT prolongation on ECG (frequency unknown)
- Pulmonary embolism, interstitial lung disease (frequency unknown)
- Idiopathic intracranial hypertension (frequency unknown)
- Stevens-Johnson syndrome / toxic epidermal necrolysis (frequency unknown)
- Erythema multiforme (frequency unknown)
- Seizures (frequency unknown)
Long-Term Effects
With prolonged androgen deprivation therapy, several metabolic and musculoskeletal changes may develop. These include decreased bone mineral density (osteoporosis) leading to increased fracture risk, metabolic syndrome with increased body fat and reduced lean muscle mass, insulin resistance, and unfavourable lipid profiles. Cardiovascular events have been reported in patients on long-term GnRH agonist therapy, though the causal relationship remains under investigation. According to the European Association of Urology, patients on long-term ADT should receive cardiovascular risk assessment, bone density monitoring, and metabolic screening at regular intervals.
Cognitive effects, including memory impairment, have also been described in the medical literature. Patients and carers should be aware that these changes may occur gradually and should report concerns to their treating physician.
When to Seek Immediate Medical Attention
Contact your doctor or seek emergency care immediately if you experience: severe difficulty breathing, sudden chest pain, signs of deep vein thrombosis (swelling and pain in a leg), sudden severe headache with vomiting and altered consciousness, widespread blistering skin rash, or signs of a serious allergic reaction (facial swelling, difficulty breathing, rapid drop in blood pressure).
How Should You Store Eligard?
Store Eligard refrigerated at 2–8°C in its original packaging. Remove from the refrigerator approximately 30 minutes before use to reach room temperature. Once removed, it can be kept at room temperature (below 25°C) for up to four weeks.
Proper storage of Eligard is essential to ensure the medication remains effective and safe. The injectable formulation is sensitive to both temperature and moisture, so specific handling guidelines must be followed.
- Temperature: Store in a refrigerator at 2–8°C (36–46°F). Do not freeze.
- Packaging: Keep in the original sealed tray packaging to protect from moisture.
- Before use: Remove from the refrigerator approximately 30 minutes before the scheduled injection to allow the product to reach room temperature.
- Room temperature storage: Once removed from the refrigerator, Eligard can be stored in its original packaging at room temperature (below 25°C / 77°F) for up to four weeks.
- Preparation: Once either tray seal is opened, the product must be prepared immediately and used right away. This is a single-use product.
- Expiry date: Check the expiry date on the carton (marked EXP). Do not use after the last day of the indicated month.
- Disposal: Do not dispose of unused medication via household waste or drains. Return unused or expired products to your pharmacy for safe disposal to protect the environment.
Keep this medication out of the sight and reach of children at all times.
What Does Eligard Contain?
Eligard contains leuprorelin acetate as the active substance in a two-syringe system: one syringe with the active powder and one with the polymer solvent.
Eligard is supplied as a powder and solvent for injection in a pre-coupled two-syringe system. The two components must be mixed together immediately before injection to form the depot solution.
Active Substance
Each pre-filled syringe B contains leuprorelin acetate. The dose varies by formulation: 7.5 mg (monthly), 22.5 mg (3-month), or 45 mg (6-month).
Other Ingredients
- Syringe A (solvent): Poly(DL-lactide-co-glycolide) 50:50 copolymer and N-methyl-2-pyrrolidone (NMP). These form the biodegradable depot matrix.
- Syringe B (powder): Leuprorelin acetate
Appearance and Packaging
Eligard is provided in a sealed tray containing a desiccant pouch and the pre-coupled syringe system (syringe A with solvent and syringe B with powder, connected via a locking connector). A sterile 20-gauge needle with a safety mechanism is included separately. When properly mixed, the resulting solution is a viscous liquid that may range from colourless to white to slightly brownish (including shades of white to slightly yellow).
Marketing Authorisation Holder
Recordati Industria Chimica e Farmaceutica S.p.A., Via Matteo Civitali 1, 20148 Milano, Italy. Eligard is approved and marketed throughout the European Economic Area, North America, and many other countries under the same or related brand names.
Frequently Asked Questions About Eligard
Eligard (leuprorelin) is used for the treatment of hormone-dependent advanced prostate cancer in adult men. It works by suppressing testosterone production to castrate levels, which slows or stops the growth of prostate cancer cells. It can be used for metastatic disease or in combination with radiation therapy for high-risk non-metastatic prostate cancer.
Eligard comes in three depot formulations: 7.5 mg given monthly, 22.5 mg given every three months, and 45 mg given every six months. Your oncologist or urologist will choose the formulation that best suits your treatment plan and lifestyle. The injection is administered subcutaneously by a healthcare professional.
The testosterone flare is a temporary increase in testosterone levels that occurs during the first 1–2 weeks of GnRH agonist therapy. This can cause a transient worsening of symptoms such as bone pain and urinary difficulties. To prevent this, your doctor may prescribe an anti-androgen medication (such as bicalutamide) starting a few days before and continuing for several weeks after the first Eligard injection.
Yes. GnRH agonists including Eligard have been associated with cardiovascular risks such as QT prolongation on the ECG, which may increase the risk of cardiac arrhythmias. Long-term testosterone suppression is also linked to metabolic changes including increased body fat, insulin resistance, and unfavourable lipid profiles, which may contribute to cardiovascular risk. Your doctor should perform baseline and periodic cardiovascular assessments during treatment.
Eligard uses a unique in-situ polymer depot technology (Atrigel) that forms a solid depot under the skin, providing sustained leuprorelin release. Other leuprorelin formulations (such as Enanton Depot) use microsphere technology. GnRH antagonists (such as degarelix) offer an alternative without the initial testosterone flare. The choice depends on individual patient factors, treatment goals, and physician preference. All achieve the same primary objective: sustained testosterone suppression.
The duration of treatment depends on your specific clinical situation. For metastatic prostate cancer, treatment is typically long-term or lifelong. For high-risk non-metastatic cancer in combination with radiotherapy, a defined treatment course (often 2–3 years) may be planned. Do not stop treatment without consulting your doctor, as this may allow the cancer to progress. Some patients may be eligible for intermittent androgen deprivation under close medical supervision.
References
- European Association of Urology (EAU). Guidelines on Prostate Cancer. 2024 Edition. Available at: uroweb.org/guidelines/prostate-cancer.
- National Comprehensive Cancer Network (NCCN). Clinical Practice Guidelines in Oncology: Prostate Cancer. Version 4.2024.
- European Medicines Agency (EMA). Eligard Summary of Product Characteristics. Last updated 2024.
- U.S. Food and Drug Administration (FDA). Eligard (leuprolide acetate) Prescribing Information. Approved labelling.
- Mottet N, van den Bergh RCN, Briers E, et al. EAU-EANM-ESTRO-ESUR-SIOG Guidelines on Prostate Cancer. Eur Urol. 2024;85(1):157-190.
- Cornford P, van den Bergh RCN, Briers E, et al. EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer—2024 Update. Eur Urol. 2024.
- Heidenreich A, Bastian PJ, Bellmunt J, et al. EAU guidelines on prostate cancer: treatment of advanced, relapsing, and castration-resistant prostate cancer. Eur Urol. 2014;65(2):467-479.
- Shore ND, Guerrero S, Goad J, et al. Long-term efficacy and tolerability of once-yearly subcutaneous leuprolide acetate in prostate cancer patients. Rev Urol. 2019;21(2-3):60-66.
- World Health Organization (WHO). Model List of Essential Medicines. 23rd List, 2023.
- National Institute for Health and Care Excellence (NICE). Prostate cancer: diagnosis and management. NICE guideline [NG131]. Updated 2024.
- Levine GN, D'Amico AV, Berger P, et al. Androgen-deprivation therapy in prostate cancer and cardiovascular risk: a science advisory from the AHA, ACS, and AUA. Circulation. 2010;121(6):833-840.
- Crawford ED, Shore ND, Moul JW, et al. Long-term tolerability and efficacy of degarelix: 5-year results from a phase III extension trial. BMC Urol. 2014;14:8.
Editorial Team
This article was written by the iMedic Medical Editorial Team, specialists in oncology, urology, and clinical pharmacology. All content is based on current international guidelines (EAU, NCCN, NICE) and peer-reviewed research published in leading medical journals.
Our editorial process follows the GRADE evidence framework, ensuring that recommendations are supported by the highest quality evidence available. All articles are independently reviewed by our Medical Review Board, which includes board-certified physicians with no conflicts of interest or commercial affiliations.