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Leuprolide (Lupron)9 residuesHWSYGLRPGEach bubble = one amino acid. Size = residue mass. Color = chemical class.Also known as: Lupron, Lupron Depot, Eligard
Thirty-five years of FDA-approved use across five separate indications. Leuprolide acetate (Lupron, Eligard, CAMCEVI) is a synthetic GnRH agonist that shuts down sex hormone production through a counterintuitive trick: it overstimulates pituitary GnRH receptors until they stop responding entirely. The first two weeks cause a hormone surge that can worsen symptoms, so flare management is non-negotiable. Prostate cancer patients, endometriosis patients, children with central precocious puberty, IVF patients, and transgender individuals all use this same molecule for completely different reasons. Depot formulations allow dosing from monthly to every six months. Bone density loss during therapy is the major long-term trade-off.
Five FDA-approved indications and 4,160 PubMed publications make leuprolide acetate one of the most studied peptide drugs on the market. Also sold as Lupron, Lupron Depot, Eligard, and CAMCEVI (CAS 53714-56-0), this synthetic nonapeptide analog of gonadotropin-releasing hormone carries a D-leucine substitution at position 6 that makes it 15 to 20 times more potent than native GnRH. The mechanism is paradoxical. Continuous GnRH receptor stimulation triggers beta-arrestin-mediated internalization, pulling receptors off the cell surface permanently. The pituitary stops releasing LH and FSH; testosterone drops below 50 ng/dL in males, and estradiol falls to postmenopausal levels in females. That suppression takes 2 to 4 weeks to establish, though. The first 1 to 2 weeks produce a hormone surge (the "flare") that can spike testosterone roughly 50% above baseline. Oncologists prescribe it for androgen deprivation in advanced prostate cancer. Gynecologists use the 3.75 mg monthly depot for endometriosis and uterine fibroids, typically capped at six months due to bone loss. Pediatric endocrinologists rely on it to halt premature puberty. Fertility specialists use the daily 1 mg subcutaneous formulation to prevent premature LH surges during IVF. The HERO trial (n=934)[1] confirmed castrate testosterone in 88.8% of prostate cancer patients at 48 weeks. Bone mineral density drops approximately 5% per year at the lumbar spine during continuous therapy, roughly ten times the rate in age-matched controls [2]. The REVELUTION RCT (SUO 2025) flagged coronary artery plaque progression with leuprolide compared to the oral GnRH antagonist relugolix, shifting conversations about cardiovascular safety in long-term ADT.
Leuprolide binds GnRH receptors on anterior pituitary gonadotroph cells with far greater affinity than the body's own GnRH. The D-Leu6 substitution blocks degradation by endopeptidases; the des-Gly10-ethylamide C-terminal modification tightens receptor binding. Together, these changes produce a molecule 15 to 20 times more potent than native GnRH. First contact activates the Gq/11 signaling pathway. Phospholipase C generates inositol trisphosphate (IP3), which triggers intracellular calcium release and the exocytosis of stored LH and FSH granules. That is the flare. Testosterone in males can surge approximately 50% above baseline during the first 1 to 2 weeks. Sustained receptor activation changes everything. Beta-arrestin recruitment drives receptor internalization through clathrin-coated pits. Those internalized receptors get routed to lysosomes for degradation rather than recycled back to the cell surface. The progressive loss of surface GnRH receptors, combined with uncoupling of the Gq cascade, leaves gonadotroph cells unable to respond to further GnRH stimulation. LH and FSH secretion drops to negligible levels within 2 to 4 weeks. Downstream, Leydig cells in males lose LH-mediated stimulation and testosterone falls below 50 ng/dL (castrate threshold). In females, estradiol reaches postmenopausal levels. This chemical castration reverses after discontinuation, but HPG axis recovery can take weeks to months. The HERO trial tracked median testosterone recovery to above 280 ng/dL at 112 days after stopping.
Leuprolide produces reliable chemical castration (testosterone <50 ng/dL in males, postmenopausal estradiol in females) via GnRH receptor downregulation. FDA-approved across 5 indications with 35+ years of clinical data (~4,160 PubMed publications). Strong RCT evidence for prostate cancer ADT, endometriosis, uterine fibroids, and CPP.
HERO Phase 3 (NEJM 2020, PMID 32396063): leuprolide sustained castrate testosterone in 88.8% at 48 weeks; REVELUTION RCT (SUO 2025): leuprolide associated with significant coronary artery plaque progression vs relugolix; PMID 40680199 (Urology Practice 2025, n=2,893): MACE incidence with ADT fell from 5.4% (2018-2020) to 2.3% (2020-2024) with improved cardiology co-management
Initial 1-2 week testosterone/estrogen flare (up to +50% above baseline); BMD loss ~5% lumbar spine/year (10× age-matched controls); cardiovascular risk with long-term ADT (MACE); cognitive impairment signal in ADT meta-analysis (Boué et al., Cancer 2024); relugolix superior for CV safety and testosterone recovery speed (HERO trial, REVELUTION 2025)
Highly effective hormone suppression acknowledged, but quality-of-life burden substantial. Endo community vocal about under-counseling on bone loss and long-term neurological/cognitive effects ("Lupron ruined my life" community). Prostate cancer patients increasingly aware of relugolix as preferred alternative for CV safety and faster testosterone recovery.
Science and community converge on: effective hormone suppression, significant menopausal/hypogonadal side effect burden, bone density loss, and cognitive/mood effects. No meaningful divergence between clinical trial outcomes and community-reported protocol approaches. Community concern about under-counseling is a process issue, not a pharmacology disagreement.
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 1mg | Daily |
| Moderate | 7.5mg | Monthly |
| Aggressive | 22.5mg | Every 3 months |
Leuprolide comes in very different formulations, and mixing them up is the most common beginner mistake. The daily subcutaneous injection is 1 mg/day from a 5 mg/mL vial (0.2 mL per dose, which is 20 units on a U-100 insulin syringe). That formulation needs refrigeration at 2 to 8 degrees C. The depot kits are a completely different product. Lupron Depot comes as lyophilized microspheres that you reconstitute with the included diluent. Swirl gently; never shake. The suspension should look uniform and milky white. Inject it immediately after mixing. You can't store reconstituted depot. Depot kits store at room temperature (15 to 30 degrees C). Don't refrigerate them. For prostate cancer patients: the bicalutamide pre-load before your first injection isn't optional if you have bone mets or high tumor burden. Start it seven days before the first depot shot. For endometriosis patients: norethindrone 5 mg/day add-back from day one reduces hot flashes and protects bone density. Most community members and current guidelines strongly recommend it.
Cycling depends entirely on indication. Prostate cancer: continuous therapy, often lifelong or until disease progression: no "off" period. Endometriosis: limited to 6 months due to bone density loss; a second 6-month course with hormonal add-back (norethindrone 5 mg/day) may be considered. Uterine fibroids: 3-6 months maximum, typically pre-surgical. Central precocious puberty: continued until appropriate age for puberty onset (typically age 11 for girls, 12 for boys), then discontinued to allow normal pubertal development.
For endometriosis/fibroids: FDA caps therapy at 6 months (monotherapy) or 12 months (with add-back norethindrone) due to cumulative bone mineral density loss (~3-6% lumbar BMD at 6 months). Bone loss may not fully recover after discontinuation. Off-drug periods allow partial BMD recovery before potential retreatment. For prostate cancer: continuous therapy without cycling is standard: sustained castration is required for disease control. Intermittent ADT (physician-directed only) is a select strategy in nonmetastatic disease but not routine. For central precocious puberty: therapy continues until appropriate pubertal age, then discontinued to allow normal HPG axis recovery and pubertal development.
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Expected: Significant pelvic pain reduction by month 1-2; lesion regression by month 3-6; fibroid volume reduction 30-60% by month 3-6
Monitor: DEXA bone mineral density at baseline; repeat at 6 months if continuing beyond 6 months. Estradiol or LH at month 1 to confirm suppression. Note: disease typically recurs after stopping: leuprolide is not a cure for endometriosis.
Daily injection (5 mg/mL solution, refrigerated) or depot kit (lyophilized microspheres with diluent, room temperature). These are not interchangeable.
For the daily subcutaneous formulation: draw 0.2 mL from the vial using a U-100 insulin syringe (that equals 20 units on the syringe, delivering 1 mg). Inject subcutaneously into the abdomen or thigh. Rotate injection sites daily. Use a 29 to 31 gauge, 1/2-inch needle.
Inject the included diluent into the vial. Swirl gently until you get a uniform milky suspension. Do not shake. Draw up the entire contents.
Lupron Depot goes deep intramuscular (gluteal). Eligard goes subcutaneous (abdomen or thigh). CAMCEVI is a prefilled syringe, no reconstitution needed, injected subcutaneously.
Depot schedule by size: 7.5 mg every month, 22.5 mg every 3 months, 30 mg every 4 months, 45 mg every 6 months.
For prostate cancer: start bicalutamide 50 mg orally daily seven days before the first depot injection. Continue for four weeks after the injection to block the testosterone flare.
Confirm testosterone suppression with a serum level at 4 to 8 weeks. Target is below 50 ng/dL.
Monitor bone mineral density at baseline and annually during prolonged therapy. Discuss a bone-active agent (denosumab 60 mg SC every 6 months or zoledronic acid 4 mg IV annually) if T-score drops below negative 1.0.
Eligard: 7.5/22.5/30/45 mg SC. CAMCEVI ETM 21 mg SC (3-month, FDA-approved 2025, NDA 219745). CAMCEVI 42 mg SC (6-month, FDA-approved 2022). CAMCEVI is a prefilled syringe: no reconstitution required.
SC may be preferred for patients or practitioners uncomfortable with deep IM gluteal injections. CAMCEVI uses ready-to-use prefilled syringe (leuprolide mesylate): eliminates reconstitution errors. Eligard uses AtriGel polymer matrix for SC depot. Both achieve equivalent castrate testosterone rates to Lupron Depot IM.
1 mg SC daily (0.2 mL of 5 mg/mL solution = 20 units on a U-100 insulin syringe); requires daily injections vs monthly-6-monthly depot
Primarily used in IVF down-regulation protocols to prevent premature LH surge during controlled ovarian stimulation. Requires refrigeration (2-8°C). For prostate cancer, equivalent castration efficacy but daily injection burden is a major disadvantage vs depot. Not indicated for endo or fibroids.
Anti-androgen co-prescription to block testosterone flare in prostate cancer during first 4 weeks. Also used long-term as combined androgen blockade (CAB) to maximize hormone suppression.
50 mg PO daily starting 7 days before first leuprolide injection; continue 4 weeks post-injection (stop) or indefinitely for CAB
Progestin add-back for endo/fibroids: substantially reduces bone loss and hot flashes without negating GnRH suppression. Enables safe treatment extension from 6 to 12 months per FDA label.
5 mg PO daily from day 1 of leuprolide; optional: add conjugated estrogens 0.625 mg/day for further symptom relief (does not negate endo suppression at this dose)
Combined with leuprolide in transgender women as part of gender-affirming hormone therapy. Leuprolide suppresses endogenous testosterone, allowing lower or more precisely controlled estradiol doses.
Estradiol dose titrated per prescribing physician; leuprolide enables more predictable estrogenic effect
Bone-protective co-prescription for long-term ADT. ASCO 2024 and NCCN recommend bone-active agent (not just calcium/Vit D) in men on ADT with osteopenia or high fracture risk. ~5% lumbar BMD loss/year without protection.
Denosumab 60 mg SC every 6 months OR zoledronic acid 4 mg IV annually; initiate based on DEXA results or baseline high fracture risk
Direct pharmacological antagonism: GnRH antagonists compete at the same receptor with opposing mechanism. Cannot be used concurrently with leuprolide.
Do not combineDirectly counteracts the intended hormonal suppression. Concurrent use renders leuprolide therapy ineffective for its oncological or gynecological indication.
Do not combineADT with leuprolide causes QTcF prolongation (median +16.7 ms per FDA label). Additive QT prolongation with concurrent QT-prolonging agents increases arrhythmia risk. FDA label warning.
ADT induces insulin resistance and metabolic syndrome in ~25-30% of patients. Antidiabetic drug requirements may change significantly during therapy; monitor and adjust doses accordingly.
Pricing updated 2026-04-09
The most serious safety consideration is bone mineral density loss. Studies show 3 to 6% lumbar spine BMD decrease within six months of therapy [2]. That loss may not fully recover after stopping, and prolonged use raises the risk of osteopenia, osteoporosis, and fracture. Vertebral fractures during ADT carry a 2.17-fold increase in all-cause mortality. Cardiovascular risk is the other big concern. The REVELUTION RCT (SUO 2025) found coronary artery plaque progression with leuprolide that was not seen with the GnRH antagonist relugolix. QTcF prolongation has a median of +16.7 ms per the FDA label. Long-term androgen deprivation raises the risk of myocardial infarction and stroke. A 2025 analysis of 2,893 patients [4] tracked MACE incidence falling from 5.4% to 2.3% as cardiology co-management improved, but the risk remains real. The initial flare phase (days 1 to 14) can be dangerous in specific populations. Prostate cancer patients with bone metastases risk spinal cord compression and urinary obstruction without anti-androgen cover. Endometriosis patients may experience temporarily worsened pelvic pain. Breakthrough bleeding is common in the first few weeks for gynecologic indications. Hot flashes affect 50 to 80% of male patients and are the most common complaint across all indications. Community reports consistently describe severe night sweats, sleep disruption, and fatigue. In females, vaginal dryness, headache, and mood changes track with the induced hypoestrogenic state. Sexual side effects are predictable given the mechanism. Decreased libido, erectile dysfunction in males, and testicular atrophy develop as testosterone reaches castrate levels. These effects are established by month 1 to 2 and persist throughout treatment. Joint and muscle pain ("Lupron arthritis") is a frequent community-reported complaint that remains poorly characterized in clinical literature. The endometriosis community is particularly vocal about cognitive effects. Brain fog, memory impairment, and depression appear in both patient forums and a 2024 ADT meta-analysis by Boue and colleagues (Cancer 2024) that confirmed cognitive impairment signals at six months. Other reported effects include injection site reactions, peripheral edema, myalgia, arthralgia, and gynecomastia. Rare but documented: seizures, anaphylaxis. When to seek medical attention: new or worsening bone pain during the first two weeks (possible tumor flare), difficulty urinating (urinary obstruction), chest pain or irregular heartbeat (cardiovascular event), or sudden severe allergic reaction. Stop therapy and contact a physician if any of these occur. Pregnancy is an absolute contraindication. Leuprolide is Category X. It causes fetal harm, spontaneous abortion, and birth defects. Pregnancy must be excluded before starting, and non-hormonal contraception is required during treatment.
Verify Leuprolide (Lupron) dosing and safety with a second opinion
FDA-approved drug manufactured by major pharmaceutical companies (AbbVie/Lupron Depot, Tolmar/Eligard, Accord/CAMCEVI). Standard supply chain through licensed pharmacies, specialty distributors, and hospital systems. Tamper-evident pre-filled kits. Compounded versions available from NABP-accredited specialty pharmacies for IVF protocols only (503A, prescription-specific). No significant gray-market sourcing concern as of 2024-2026.
| Test | When | Target |
|---|---|---|
| Serum testosterone (males) | 4 weeks after first injection, then every 3-6 months | <50 ng/dL (FDA castrate threshold); some NCCN guidelines target <20 ng/dL for optimal response |
| Serum estradiol (females) | 4 weeks after first injection, then every 3-6 months | <20-30 pg/mL (postmenopausal range) |
| PSA (prostate cancer only) | Every 3 months during ADT | <0.2 ng/mL (deep PSA suppression); rising PSA with castrate testosterone = evaluate for CRPC |
| DEXA bone mineral density | Baseline before starting; repeat at 6 months (endo) or annually (long-term ADT for prostate cancer) | T-score <−1.0 (osteopenia): consider adding denosumab or bisphosphonate. T-score <−2.5 (osteoporosis): treat with bone-active agent. |
| Fasting glucose, HbA1c, fasting lipid panel | Baseline; then every 6-12 months during ADT | Standard metabolic targets; flag HbA1c ≥6.5% or significant dyslipidemia |
| ECG and cardiovascular risk assessment | Baseline; annually in patients with pre-existing cardiovascular disease or high MACE risk | QTcF <450 ms; any new arrhythmia requires evaluation |
Confirm and maintain castrate levels. Inadequate suppression or rising testosterone on therapy indicates treatment failure or CRPC.
Confirm postmenopausal suppression for endo/fibroid indications. Inadequate suppression may explain persistent symptoms.
PSA rise while testosterone is castrate is the primary criterion for CRPC diagnosis and signals need for next-line therapy.
Leuprolide causes ~5% lumbar BMD loss/year (~10× age-matched controls). Guides initiation of bone-active agents. Vertebral fractures with ADT carry 2.17× increased all-cause mortality.
ADT induces insulin resistance and metabolic syndrome in ~25-30% of patients. May require initiation or dose adjustment of antidiabetic and statin therapy.
Leuprolide causes QTcF prolongation (median +16.7 ms per FDA label). Long-term ADT increases MACE risk. REVELUTION 2025 shows coronary plaque progression vs relugolix: consider cardiology co-management or relugolix switch in high-CV-risk patients.
Initial GnRH agonist flare begins. LH and FSH rise sharply. Testosterone or estrogen levels start increasing above baseline.
Peak flare effect. Testosterone may surge ~50% above baseline in males. Temporary symptom worsening possible: tumor flare in prostate cancer, increased pelvic pain in endometriosis. Anti-androgen cover recommended during this window for prostate cancer.
GnRH receptor downregulation takes effect. LH and FSH begin falling. Testosterone/estrogen levels decline progressively toward suppressed ranges.
Full biochemical suppression achieved. Testosterone reaches castrate levels (<50 ng/dL) in the majority of patients. Symptom improvement begins in endometriosis and fibroid patients.
Sustained hormonal suppression maintained by depot formulation. Prostate cancer: PSA decline and disease stabilization. Endometriosis: pain relief and lesion regression. Fibroids: volume reduction of 30-60%. Monitor bone mineral density.
Days 1 to 14 (Flare Phase): The GnRH agonist surge hits immediately. LH and FSH spike, pulling testosterone roughly 50% above baseline in males and raising estradiol in females. Peak flare lands around days 7 to 14. For prostate cancer patients with bone metastases, this window carries real danger: spinal cord compression and urinary obstruction are documented risks without bicalutamide cover. Endometriosis patients typically experience worsened pelvic pain. Community reports consistently describe being blindsided by the flare because pre-treatment counseling was inadequate. Weeks 2 to 4: GnRH receptors start internalizing. LH and FSH begin their decline. Testosterone starts dropping toward castrate levels in most males; estradiol falls in females. The endometriosis and trans communities describe this transition as "overnight menopause." Hot flashes intensify. Libido drops. Cognitive changes start showing up. Some endometriosis patients notice pain improving by the end of week four. Month 1 to 2: Full biochemical suppression establishes itself. Testosterone hits castrate levels (below 50 ng/dL) in over 95% of patients. PSA starts declining in prostate cancer. Endometriosis patients usually get their first clear pain relief signal by month two. Hot flashes peak in intensity. Brain fog and fatigue are prominent in both the endometriosis and prostate cancer communities. Month 3 to 6: Sustained suppression holds steady. Prostate cancer patients see PSA nadir and disease stabilization. Fibroids shrink 30 to 60% in volume. Endometriosis pain relief is substantial, but the endo community is vocal about this not being a cure. Joint pain and "Lupron arthritis" complaints peak during this window. Bone mineral density loss accumulates: 3 to 6% lumbar spine BMD at six months per FDA label data, up to 5% per year during ongoing ADT. Month 6 and beyond: Treatment duration splits by indication. Endometriosis and fibroids: the FDA caps therapy at six months without add-back, twelve months with norethindrone. Symptoms typically recur after stopping. Prostate cancer: continuous therapy is standard. The REVELUTION RCT (2025) raised flags about coronary artery plaque progression with leuprolide compared to relugolix, shifting the conversation toward cardiovascular co-management. Cognitive effects confirmed in a 2024 ADT meta-analysis by Boue and colleagues at the six-month mark.
GnRH receptor agonist stimulation causes LH/FSH surge. Testosterone rises ~50% above baseline in males; estradiol rises in females. Peak flare ~7-14 days. Tumor flare documented in metastatic prostate cancer: spinal cord compression and urinary obstruction are serious risks without anti-androgen cover.
Worsened prostate cancer symptoms (urinary obstruction, bone pain in mets), increased endometriosis pain, breakthrough bleeding. Community frequently reports inadequate pre-treatment counseling on the flare: many patients blindsided. Prostate cancer patients: bicalutamide pre-loading is widely communicated in community as non-negotiable.
GnRH receptor internalization progresses. LH/FSH begin declining. Testosterone starts falling toward castrate range in most males. Estradiol declines in females. This phase represents transition from agonist stimulation to receptor downregulation.
"Overnight menopause": common endo and trans community description. Hot flashes intensifying. Initial sexual side effects emerging (libido loss, erectile dysfunction). Mood and cognitive changes beginning. Some endo patients report pain beginning to improve by end of week 4.
Castrate testosterone (<50 ng/dL) or postmenopausal estradiol levels achieved in 95%+ of patients. PSA decline begins in prostate cancer. Endometriosis pain reduction measurable. Fibroid blood flow reducing.
Hot flashes at peak intensity. Significant fatigue. Cognitive effects ("brain fog," memory issues) reported prominently in endo and prostate cancer communities. Endo patients: notable pain reduction by month 2 in most cases: often the first clear positive signal. Prostate cancer: sexual dysfunction established.
Maintained castrate/menopausal hormone levels. Prostate cancer: PSA nadir, disease stabilization. Endometriosis/fibroids: 30-60% fibroid volume reduction, lesion regression, significant pain relief. Bone mineral density loss accumulating: ~3-6% lumbar BMD at 6 months (FDA label data); up to 5%/year during ongoing ADT.
Most patients adjusted to hot flashes. Joint pain and "Lupron arthritis" complaints peak. Endo community: substantial pain relief but frustration about no cure: symptoms recur after stopping. Prostate cancer: PSA decline is reassuring to most patients but sexual dysfunction fully established.
Endo/fibroids: FDA limits therapy to 6 months (monotherapy) or 12 months (with add-back) due to cumulative bone loss. Prostate cancer: continuous therapy standard; ADT-associated MACE risk elevates with duration. REVELUTION 2025 RCT: leuprolide showed significant near-term coronary artery plaque progression not seen with relugolix. Cognitive effects confirmed in ADT meta-analysis (Boué et al., Cancer 2024) at 6 months.
Endo patients: frustration at treatment limit and symptom recurrence. Prostate cancer: adapting to "new normal" of ongoing ADT. Growing community awareness of relugolix as alternative. Long-term endo patients discussing elagolix (Orilissa) and dienogest as alternative maintenance strategies after leuprolide completion.
Source: FDA prescribing information: terminal elimination half-life of approximately 3 hours after IV bolus in healthy male volunteers. Depot formulations sustain therapeutic drug levels for 1-6 months via microsphere/polymer matrix controlled release.
Loading the interactive decay curve.
Leuprolide acetate holds full FDA approval across multiple indications: advanced prostate cancer (1985), endometriosis (1990), uterine fibroids, central precocious puberty, and as part of IVF protocols. Brand names include Lupron, Lupron Depot (AbbVie), Eligard (Tolmar), and CAMCEVI (Accord). Generic formulations are available for the daily injection and select depot sizes. Leuprolide requires a prescription in the United States and is a scheduled pharmaceutical product, not a research peptide. It is not available through gray-market peptide vendors. Legitimate sourcing is through licensed pharmacies only. WADA prohibits leuprolide in competition and out-of-competition testing for athletes. It appears on the Prohibited List under S2 (Peptide Hormones, Growth Factors, Related Substances, and Mimetics) and S4 (Hormone and Metabolic Modulators). Medicare Part B covers leuprolide depot for prostate cancer under buy-and-bill J-codes. Commercial insurance typically covers it across approved indications. AbbVie offers a patient savings card reducing commercially insured copays to approximately $10 per dose. This content is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before starting any treatment.
Peptide Schedule Research TeamReviewed Apr 20269 Citations
