Compound Comparison Hub

Semaglutide is a selective GLP-1 receptor monoagonist; tirzepatide is a dual GLP-1R/GIPR co-agonist, giving it an additional incretin signalling pathway not present in semaglutide.

Liraglutide is a first-generation GLP-1R selective agonist with a 13-hour half-life requiring daily dosing; tirzepatide is a second-generation GLP-1R/GIPR dual agonist with ~118–171h half-life for weekly dosing and substantially greater weight-reduction magnitude.

BPC-157 is a gastric pentadecapeptide that acts via VEGFR2 and upregulates growth factor expression; TB-500 is a synthetic fragment of thymosin beta-4 that promotes actin polymerisation and cellular migration.

CJC-1295 is a long-acting GHRH analogue that acts at the GHRH receptor; ipamorelin is a selective ghrelin mimetic acting at GHSR-1a. The two compounds stimulate GH through distinct receptor systems that are synergistic when used together in research.

Both ipamorelin and GHRP-2 are GHSR-1a agonists (ghrelin mimetics), but ipamorelin is significantly more receptor-selective: it does not stimulate cortisol, ACTH, or prolactin at GH-releasing doses, while GHRP-2 produces modest elevations in all three.

MK-677 (ibutamoren) is an orally bioavailable, non-peptide GHSR-1a agonist with a long half-life (~24 hours); ipamorelin is an injectable pentapeptide with a short half-life (~2 hours) and greater receptor selectivity for isolated pulsatile GH research.

Tirzepatide activates GLP-1R and GIPR (dual agonist); retatrutide adds GCGR co-agonism (tri-agonist), providing thermogenic energy expenditure through glucagon receptor activation — a mechanism absent in tirzepatide.

Semax is an ACTH(4-7) analogue that upregulates BDNF and activates TRKB signalling, driving neuroprotective and cognitive effects; Selank is a synthetic tuftsin analogue with anxiolytic and immune-modulatory activity, also studied for cognitive effects through serotonin and dopamine system modulation.

GHK-Cu is a copper-binding tripeptide that promotes collagen synthesis and remodelling through fibroblast activation; BPC-157 is a 15-amino-acid gastric peptide that drives angiogenesis through VEGFR2 and upregulates multiple growth factors.

Melanotan I (afamelanotide) is an MC1R-selective agonist focused on skin pigmentation research; Melanotan II activates MC1R, MC3R, MC4R, and MC5R — its broader receptor profile underlies its sexual function and appetite research effects absent in Melanotan I.

PT-141 (bremelanotide) is a cyclic heptapeptide metabolite of Melanotan II that has been refined for MC4R-biased agonism and received FDA approval for hypoactive sexual desire disorder; Melanotan II is the parent compound with broader receptor activity across MC1R, MC3R, MC4R, and MC5R, and remains an investigational research compound without regulatory approval.

Epitalon is a synthetic pineal tetrapeptide that activates telomerase (hTERT) to extend telomere length; Humanin is a mitochondria-derived peptide (mitokine) that suppresses apoptosis via STAT3 and reduces cellular stress — two mechanistically distinct longevity pathways.

IGF-1 LR3 has a ~20–30 hour half-life from resistance to IGF-binding proteins; DES(1-3) IGF-1 has a short half-life (~20 min) but ~10× greater potency at the IGF-1 receptor — the two analogues are optimised for different research protocols.

Thymosin Alpha-1 is a thymic peptide that enhances adaptive immunity via T-cell maturation and cytokine modulation; LL-37 is the only human cathelicidin, acting as a direct antimicrobial and innate immune modulator — two complementary arms of the immune response.

Sermorelin is the minimal bioactive GHRH fragment (residues 1–29); tesamorelin is a stabilised full-length GHRH(1–44) analogue with an N-terminal trans-3-hexenoic acid group that confers resistance to dipeptidylpeptidase IV (DPP-IV) cleavage and a significantly longer duration of GH-stimulating action.

CJC-1295 (no DAC) is a modified GHRH(1–29) analogue with a half-life of approximately 30 minutes to 2 hours, producing physiological pulsatile GH release; CJC-1295 DAC adds a maleimido-propionic acid Drug Affinity Complex (DAC) that covalently binds circulating serum albumin, extending half-life to approximately 6–8 days and converting pulsatile GH stimulation to a sustained continuous pattern.

Epitalon (Ala-Glu-Asp-Gly) is a synthetic tetrapeptide from the pineal gland that activates telomerase (hTERT) to extend telomere length; Thymalin is a thymic polypeptide bioregulator complex derived from calf thymus extract that modulates adaptive immunity, restores thymic function, and has demonstrated lifespan extension in controlled rodent studies — both developed within the St Petersburg bioregulator peptide research programme (Khavinson et al.).

AOD-9604 (hGH 177-191 + N-terminal Tyr) is a structurally modified GH fragment that advanced through Phase IIb human trials for an obesity indication; HGH Fragment 176-191 is the native C-terminal GH fragment that established the proof of concept for lipolytic GH dissociation, remaining at preclinical research stage. Both activate adipocyte lipolytic cascades without GH receptor engagement or IGF-1 induction.

BPC-157 (Body Protection Compound-157) is a 15-amino-acid gastric pentadecapeptide with an extensive preclinical literature spanning gut healing, tendon repair, and neurological protection. KPV (Lys-Pro-Val) is a C-terminal tripeptide fragment of alpha-melanocyte-stimulating hormone (α-MSH) with demonstrated NF-κB inhibitory and gut anti-inflammatory properties in IBD preclinical models. Both are under FDA 503A compounding review and listed for PCAC evaluation in July 2026.

Semaglutide (Ozempic/Wegovy) is an FDA-approved GLP-1 receptor agonist with robust Phase III evidence for type 2 diabetes and obesity. Retatrutide (LY3437943) is an investigational triple agonist targeting GIP, GLP-1, and glucagon receptors simultaneously — Phase II data (NEJM, 2023) reported approximately 24% weight reduction at 48 weeks, substantially exceeding semaglutide's ~15% in STEP trials. Retatrutide remains in Phase III development as of 2026.

SS-31 targets the inner mitochondrial membrane directly via cardiolipin binding to stabilize cristae architecture and reduce ROS; MOTS-c is a mitochondria-derived peptide that acts as a nuclear-encoded metabolic regulator, mimicking exercise-induced AMPK activation.

GHK is the free glycine-histidine-lysine tripeptide with inherent copper-chelating capacity; GHK-Cu is its copper(II) complex, which is the biologically active form responsible for most published wound-healing, antioxidant, and gene-regulatory effects.