Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Gonadorelin and PT-141 — mechanism, dosing, side effects, legal status, and pricing.
Gonadorelin is a synthetic decapeptide identical to endogenous gonadotropin-releasing hormone (GnRH/LHRH; sequence pyroGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2). It was historically FDA-approved as Factrel (diagnostic GnRH stimulation test) and Lutrepulse (pulsatile IV pump for hypothalamic amenorrhea); both products are discontinued in the US. Gonadorelin remains on the FDA Category 1 bulk substances list and is widely compounded, most commonly as an off-label adjunct to TRT intended to preserve HPG-axis signaling.
PT-141 (bremelanotide) is a cyclic heptapeptide melanocortin receptor agonist derived from melanotan II. It is FDA-approved as Vyleesi (2019) for hypoactive sexual desire disorder (HSDD) in premenopausal women only. It acts centrally through the melanocortin system rather than on peripheral vasculature.
Gonadorelin
PT-141
Category
Legal Status
Mechanism
Dose Range
Route
Frequency
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Gonadorelin
PT-141
COA corpus from Disclosed Labs — independently tested batches only.
Gonadorelin
4
COAs
99.6%
Avg purity
2
Labs
PT-141
83
COAs
99.7%
Avg purity
14
Labs
The historical FDA-approved gonadorelin products (Factrel for diagnostic pituitary testing; Lutrepulse for pulsatile ovulation induction in hypothalamic amenorrhea) are discontinued commercially, but gonadorelin remains on the FDA Category 1 bulk substances list and is compounded under 503A/503B. Pulsatile pump delivery (every 60–120 minutes) is the clinical gold standard for hypothalamic amenorrhea and congenital hypogonadotropic hypogonadism, with systematic-review evidence supporting high ovulation rates (Tranoulis 2018, PMID 29605411) and faster spermatogenesis versus cyclical hCG/hMG in CHH men (Zhang 2018/2019, PMID 30569789; Büchter 1998, PMID 9758439). Use as a TRT adjunct in place of hCG is widespread in men's-health practice but is off-label and has limited dedicated controlled-trial data; its ability to maintain intratesticular testosterone once the HPG axis is fully suppressed by exogenous testosterone has not been rigorously established.
Key references
Bremelanotide received FDA approval in June 2019 (NDA 210557) based on the two Phase III RECONNECT trials reported by Kingsberg, Simon, Clayton, Portman et al. in Obstet Gynecol 2019 (PMID 31599840). Pooled 24-week data showed statistically significant increases in the Female Sexual Function Index desire domain and decreases in the Female Sexual Distress Scale compared with placebo, with long-term 52-week open-label safety reported in the companion paper (PMID 31599847). Earlier clinical programs in men with erectile dysfunction — including intranasal bremelanotide and the subcutaneous sildenafil-salvage study by Safarinejad & Hosseini (J Urol 2008, PMID 18206919) — showed modest efficacy but did not lead to approval in men. Safety monitoring shows transient SBP elevation (~6 mmHg) with reflex bradycardia resolving within ~12 hours; nausea (~40%) is the most common adverse event and typically diminishes with subsequent doses. Focal hyperpigmentation has been reported with repeated use, consistent with MC1R activity.
Gonadorelin and PT-141 are both in the Hormone category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Dosing Notes
Half-life
Side Effects
Contraindications
Lab Testing
Disclosed Labs