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Peptides

Deep profiles for diligence—not product pages. Filter by goal or open any profile for mechanism, evidence, and citations.

Retatrutide

Stronger clinical signal

An investigational triple agonist (GLP-1, GIP, and glucagon receptors) studied for obesity and metabolic disease. Currently the highest-profile name in the space—widely framed as the next-generation successor to tirzepatide, with heavy search interest among fitness audiences.

Fat loss · Metabolic

Semaglutide

Stronger clinical signal

A GLP-1 receptor agonist (marketed as Ozempic, Wegovy, and Rybelsus) with robust clinical evidence for glycemic control and weight management. The molecule that mainstreamed this category and a reference point for understanding incretin-based approaches discussed in fitness communities.

Fat loss · Metabolic

Tirzepatide

Stronger clinical signal

A dual GIP/GLP-1 receptor agonist (marketed as Mounjaro and Zepbound) with extensive clinical data in type 2 diabetes and obesity. Frequently compared head-to-head with semaglutide in conversations about metabolic peptides and body recomposition.

Fat loss · Metabolic

BPC-157

Emerging

A synthetic peptide fragment derived from a gastric protein, widely discussed for soft-tissue recovery. Human evidence remains limited relative to its online popularity.

Recovery · Skin / repair · Gut health

Cagrilintide

Stronger clinical signal

A long-acting amylin-receptor analogue from Novo Nordisk, studied alone and paired with semaglutide (as "CagriSema") for weight management and type 2 diabetes. Currently one of the most-discussed "next after tirzepatide/retatrutide" names in metabolic-peptide circles.

Metabolic · Fat loss

Survodutide

Stronger clinical signal

A Boehringer Ingelheim glucagon-receptor/GLP-1-receptor dual agonist in late-stage development for obesity and MASH (fatty liver disease). Part of the current wave of multi-receptor peptides competing with tirzepatide and retatrutide for the metabolic-peptide spotlight.

Metabolic · Fat loss

TB-500

Emerging

A synthetic peptide associated with thymosin beta-4 research, commonly discussed alongside soft-tissue recovery and mobility. Often paired conversationally with BPC-157.

Recovery · Skin / repair

CJC-1295

Limited human data

A growth hormone–releasing hormone (GHRH) analogue discussed for GH-axis support. Often mentioned with ipamorelin in fitness forums as a commonly discussed pairing.

Muscle / GH axis · Recovery · Sleep / recovery adjunct

Ipamorelin

Limited human data

A selective growth hormone secretagogue (ghrelin-receptor agonist) discussed for GH pulses with a relatively favorable selectivity profile in older literature.

Muscle / GH axis · Recovery · Sleep / recovery adjunct

Tesamorelin

Stronger clinical signal

A synthetic GHRH analogue with an approved indication for reducing excess abdominal fat in specific HIV-associated lipodystrophy contexts—often referenced when discussing visceral fat and GH axis research.

Fat loss · Muscle / GH axis · Metabolic

Semax

Limited human data

A synthetic heptapeptide analogue of ACTH(4-10), registered as a prescription drug in Russia for ischemic stroke and optic nerve conditions. One of the most frequently discussed "nootropic peptides" in biohacking communities, alongside Selank.

Cognitive / nootropic · Neuroprotection

Selank

Limited human data

A synthetic heptapeptide anxiolytic developed alongside Semax at Russia's Institute of Molecular Genetics, studied for generalized anxiety disorder and neurasthenia. Frequently paired with Semax in nootropic-peptide discussions.

Cognitive / nootropic · Mood / anxiety

MOTS-c

Emerging

A mitochondria-derived peptide researched for metabolic regulation and exercise-related stress responses. Still early relative to incretin drugs, but frequently searched in biohacking circles.

Metabolic · Fat loss · Recovery · Longevity / aging

Thymosin Alpha-1

Stronger clinical signal

A 28-amino-acid immunomodulatory peptide, marketed in dozens of countries as Zadaxin/thymalfasin for chronic viral hepatitis and as an immune-response adjunct in cancer and infection. One of the few peptides in this space with genuine international drug-approval history.

Immune support · Longevity / aging

Bremelanotide

Stronger clinical signal

A melanocortin-receptor agonist derived from Melanotan II research, FDA-approved as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. Notable as one of the only peptides in this category with a formal drug approval.

Sexual health

GHK-Cu

Limited human data

A copper-binding tripeptide studied in skin biology and remodeling. Appears in topical cosmetic research and in online discussions of recovery and tissue quality.

Skin / repair · Recovery

Noopept

Limited human data

A synthetic dipeptide developed as a piracetam analogue, sold as a prescription nootropic in Russia for cognitive impairment following stroke and traumatic brain injury. A recurring name in international nootropic-stacking discussions despite thin Western trial data.

Cognitive / nootropic

Melanotan II

Limited human data

A non-selective melanocortin-receptor agonist originally studied for skin tanning and erectile dysfunction, whose sexual-desire side effects led directly to the development of the FDA-approved drug bremelanotide (PT-141). Widely sold gray-market for tanning despite no approval for that use.

Sexual health

Cerebrolysin

Limited human data

A mixture of low-molecular-weight peptides and amino acids derived from purified porcine brain proteins, approved in several countries for stroke and traumatic brain injury recovery. Distinct from single-sequence research peptides—it's a multi-component biological preparation.

Cognitive / nootropic · Neuroprotection

Larazotide Acetate

Limited human data

A first-in-class oral peptide designed to keep intestinal tight junctions closed, studied as an adjunct therapy for celiac disease alongside a gluten-free diet. One of the more rigorously trialed gut-health peptides, with multiple completed phase 2 RCTs.

Gut health

LL-37

Limited human data

The only human cathelicidin antimicrobial peptide, naturally released at wound margins during healing. Studied as a synthetic topical treatment for hard-to-heal chronic wounds, giving it more human RCT support than most "recovery peptide" research chemicals.

Immune support · Skin / repair

Kisspeptin-54

Limited human data

A naturally occurring neuropeptide that is the master regulator of the reproductive hormone axis, now in early clinical development as a fertility and psychosexual therapeutic. Distinct from the melanocortin-based sexual-health peptides—it works directly on the reproductive hormone cascade.

Sexual health

AOD-9604

Limited human data

A fragment of the C-terminal region of human growth hormone historically investigated for fat metabolism without full GH receptor agonism claims.

Fat loss

Humanin

Emerging

A 24-amino-acid peptide encoded within mitochondrial DNA itself, part of a growing family of "mitochondrial-derived peptides" (alongside MOTS-c) studied in aging and cellular-stress biology.

Longevity / aging

A nonapeptide isolated from rabbit cerebral venous blood in the 1970s and named for its apparent sleep-promoting effect in early animal work. One of the oldest "sleep peptides" discussed online, though its own reviewers call its biological role "a still unresolved riddle."

Sleep / recovery adjunct

KPV

Emerging

The smallest active fragment of alpha-MSH (just three amino acids), studied almost entirely in mouse models of inflammatory bowel disease as an anti-inflammatory candidate. A clear example of a peptide with real preclinical mechanism data but essentially no human trials.

Gut health · Skin / repair

ARA-290 (Cibinetide)

Limited human data

An 11-amino-acid peptide engineered from a non-erythropoietic region of erythropoietin, designed to activate tissue-repair signaling without stimulating red blood cell production. Studied in phase 2 human trials for small-fiber neuropathy—one of the more clinically tested "tissue protective" peptides.

Recovery · Neuroprotection

Epitalon

Emerging

A synthetic tetrapeptide associated with pineal peptide research and aging biology conversations. Evidence is largely historical/preclinical with limited modern RCT coverage.

Longevity / aging · Sleep / recovery adjunct · Recovery

FOXO4-DRI

Emerging

A lab-designed "D-retro-inverso" peptide built to disrupt one specific protein-protein interaction that keeps aged cells alive, making it a purpose-built senolytic rather than a naturally occurring hormone fragment. Widely cited in longevity media as the "reverse aging in mice" peptide.

Longevity / aging

Oxytocin

Limited human data

A naturally occurring hormone-peptide best known for its role in childbirth and lactation, popularized far beyond that as the "trust" or "bonding" molecule after a famous 2005 economics experiment. A useful case study in how a single influential paper can outrun its own replication record.

Mood / anxiety

Evidence labels

  • EmergingMostly preclinical or early signals; human athletic data is thin.
  • Limited human dataSome human pharmacology or small studies; outcomes for fitness use remain limited.
  • Stronger clinical signalSupported by larger clinical trials in defined medical populations.

Same color code everywhere on STACKD: green = stronger clinical/human data, amber = limited human data or mechanism, slate = emerging/anecdotal, and oxblood = an in-house STACKD summary.