Comparison
Leuprorelin vs. Sincalide
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Research other
Research other
CAS no.
53714-56-0
25126-32-3
Molecular weight
1209.4 g/mol
1143.29 g/mol
Half-life
3 h
no data
Sequence
Pyr-His-Trp-Ser-Tyr-D-Leu-Leu-Arg-Pro-NHEtAsp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2Mechanism of action
Leuprorelin
Leuprorelin is a GnRH-receptor agonist. After binding to pituitary GnRH receptors, it first causes a transient surge in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release — the so-called flare. With continuous, non-pulsatile exposure the receptors are downregulated and desensitized, suppressing gonadotropin secretion and consequently lowering sex steroids (testosterone or estradiol) to low levels. This mechanism underlies the literature-described use in hormone-dependent conditions.
Sincalide
Sincalide activates CCK receptors, triggering gallbladder contraction and pancreatic enzyme secretion. This effect is used diagnostically to measure the gallbladder ejection fraction (e.g. in HIDA scintigraphy).
Evidence base
Highest evidence
Human RCT
Human trial
Studies
4
0
of which in humans
4
0
Effects recorded
4
1
Open conflicts
1
0
Documented adverse events
3
1
Legal status
Full entries
Frequently asked questions
- What is the difference between Leuprorelin and Sincalide?
- Leuprorelin is classified as "Research other", while Sincalide is classified as "Research other". Leuprorelin: Leuprorelin (also leuprolide) is a synthetic nonapeptide analogue of gonadotropin-releasing hormone (GnRH/LHRH). It is an approved prescription medicine in several jurisdictions, including for advanced prostate cancer, endometriosis, uterine fibroids and central precocious puberty. This page neutrally summarizes the evidence base and legal status and is not a usage or dosing recommendation. Sincalide: Sincalide is the synthetic C-terminal octapeptide of the hormone cholecystokinin (CCK-8). As Kinevac it is FDA-approved to stimulate gallbladder contraction for diagnostic imaging. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, Leuprorelin or Sincalide?
- The highest available evidence level is "Human RCT" for Leuprorelin and "Human trial" for Sincalide. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.
- What is the legal status of Leuprorelin and Sincalide in Germany and the United States?
- Germany: Leuprorelin — Prescription, Sincalide — Unclear. United States: Leuprorelin — Prescription, Sincalide — Prescription. These are factual summaries with source and review date on the individual pages.