01Reference / Glossary

Peptide glossary, with mechanism, evidence, and PGx flags.

A working A–Z reference for the peptides discussed across our formulary. Each entry lists the receptor target, the strongest available evidence, regulatory status, and any pharmacogenomic variants we screen for in GeneRx.

12 entries

BPC-157

Body Protection Compound 157

Evidence CInvestigational

Synthetic gastric peptide fragment

15-amino-acid fragment derived from human gastric juice protein BPC. Animal data suggests upregulation of VEGFR2 and modulation of NO pathway, with downstream angiogenic and tendon-healing effects.

Evidence: Strong rodent and ex vivo data; almost no controlled human trials. Not FDA approved.

CJC-1295

Evidence CInvestigational

Long-acting GHRH analog

Modified GHRH(1-29) with DAC linker that binds albumin, extending half-life and producing pulsatile GH release over days.

Evidence: Phase II (J Clin Endocrinol Metab 2006) showed sustained GH/IGF-1 elevation; no large RCTs in healthy adults.

InternalGHRHR— Loss-of-function variants reduce response.

Ipamorelin

Evidence CInvestigational

GHRP / ghrelin receptor agonist

Selective GHS-R1a agonist. Triggers GH pulse without significant cortisol/prolactin spikes, unlike GHRP-2/6.

Evidence: Small healthy-volunteer studies; no large efficacy RCTs.

Liraglutide

Saxenda · Victoza

Evidence AFDA approved

GLP-1 receptor agonist

Daily GLP-1R agonist with C16 fatty-acid linker for albumin binding; precursor to semaglutide chemistry.

Evidence: SCALE (JAMA 2015): 8.0% weight loss at 56 weeks at 3.0 mg.

InternalGLP1R— Same response variants as semaglutide.

MOTS-c

Evidence DInvestigational

Mitochondrial-derived peptide

16-amino-acid peptide encoded in mitochondrial 12S rRNA. Activates AMPK pathway; preclinical evidence for insulin sensitization and exercise-mimetic effects.

Evidence: Preclinical only — no human RCTs.

Oxytocin

Evidence BFDA approved

Neurohypophyseal peptide hormone

Nonapeptide acting at OXTR. Central effects on social cognition and pair-bonding; peripheral effects on uterine contraction and milk let-down.

Evidence: FDA approved for labor induction; intranasal use for behavioral indications remains investigational.

InternalOXTR— rs53576 modulates social-cognitive response.

PT-141 (Bremelanotide)

Vyleesi

Evidence AFDA approved

Melanocortin MC4R agonist

Cyclic 7-amino-acid analog of α-MSH. CNS-mediated effects on sexual desire via MC4R signaling.

Evidence: RECONNECT Phase III: significant improvement in HSDD endpoints in premenopausal women.

InternalMC4R— Loss-of-function variants reduce response; gain-of-function rare.

Semaglutide

Ozempic · Wegovy · Rybelsus

Evidence AFDA approved

GLP-1 receptor agonist

Long-acting GLP-1R agonist. Stimulates glucose-dependent insulin secretion, slows gastric emptying, and reduces appetite via hypothalamic POMC/CART neurons.

Evidence: STEP-1 (NEJM 2021): ~14.9% mean weight loss at 68 weeks vs 2.4% placebo.

InternalGLP1R— rs6923761 (Gly168Ser) associated with variable weight-loss response.

CPICCYP3A4— Minor metabolism — not clinically actionable for semaglutide alone.

Sermorelin

Evidence BCompoundable

GHRH(1-29)

Truncated natural GHRH that stimulates pituitary GH release through endogenous pulse architecture.

Evidence: FDA-approved historically for pediatric GH deficiency diagnostic; commonly compounded for adult use.

InternalGHRHR— Same as CJC-1295.

Tesamorelin

Egrifta

Evidence AFDA approved

GHRH analog

Stabilized GHRH analog approved to reduce visceral adipose tissue in HIV-associated lipodystrophy.

Evidence: Phase III trials (NEJM 2007): ~15% VAT reduction vs placebo.

Thymosin Alpha-1

Zadaxin

Evidence BRestricted

Immunomodulatory peptide

28-amino-acid peptide that modulates dendritic cell maturation and T-cell function via TLR pathways.

Evidence: Approved in 35+ countries for hepatitis B/C adjunctive therapy; not FDA approved in US.

Tirzepatide

Mounjaro · Zepbound

Evidence AFDA approved

Dual GIP/GLP-1 receptor agonist

Single peptide engaging both GIP and GLP-1 receptors. Combined incretin action drives larger weight loss than GLP-1 alone in head-to-head trials.

Evidence: SURMOUNT-1 (NEJM 2022): up to 22.5% weight loss at 72 weeks at 15 mg.

InternalGIPR— rs1800437 (Glu354Gln) modulates GIP-arm sensitivity.