Peptide research library · 169 cited guides
Guide
Buying guides & basics
Not a ranking — the one email that sorts the market, and the six supplier checks in order of how much signal each carries.
Guide
Buying guides & basics
Prescription, 503A compounding or the research-chemical market — the compound decides which route is open to you, not the seller.
Guide
Immune & gut
Approved in 30+ countries but not the US. Why the N-terminal acetyl group is the substitution point to check.
Guide
Growth hormone axis
Discontinued commercially, not for safety — which leaves two routes. Why degradation matters more than identity for this one.
Guide
Growth hormone axis
An 83-residue analog where folding matters as much as purity, and 'LR3' is the part that gets substituted.
Guide
Growth hormone axis
Six residues, cheap to make, rarely worth faking — so the sourcing question here is mostly about handling.
Guide
Growth hormone axis
A decapeptide whose effect inverts with delivery pattern — which makes the GnRH-analog family the substitution risk.
Research peptides are sold online in the US as research-use-only reference compounds — legal to buy for laboratory work, not approved for human use, and not sold with dosing instructions. The market is unregulated on quality, which means the supplier you choose matters more than the price you pay.
There is exactly one question that separates a real supplier from a reseller: can they hand you a third-party certificate of analysis whose batch number matches the vial in your hand? Everything below is downstream of that. If a supplier can't produce a batch-matched COA from a named external lab, nothing else about their offer is verifiable — including the purity number on the label.
Retatrutide
Triple GIP/GLP-1/glucagon agonist — the most-searched research peptide in the world, and still investigational.
BPC-157
Pentadecapeptide from gastric juice. The most-cited tissue-repair compound in the field, and the one with the thinnest human evidence.
Tirzepatide
Dual GIP/GLP-1 agonist behind Mounjaro and Zepbound. Approved as a drug; sold separately as a research compound.
NAD+
The redox cofactor at the centre of the longevity conversation. Injectable, IV, and oral-precursor routes all behave differently.
GLOW blend
BPC-157 + TB-500 + GHK-Cu in one vial. Three well-studied constituents, zero trials on the combination.
KPV
The C-terminal tripeptide of α-MSH. Anti-inflammatory signal in gut and skin models without the pigmentation effect.
Semaglutide
The GLP-1 analog behind Ozempic and Wegovy — the molecule that started the metabolic-peptide boom.
Ipamorelin
Selective GHS-R agonist — a growth-hormone secretagogue that leaves cortisol and prolactin alone.
MOTS-c
Mitochondrial-derived peptide that activates AMPK. The closest thing the field has to an exercise mimetic.
CJC-1295
GHRH analog. The no-DAC form pulses; the DAC form doesn't — and that difference drives everything else.
Cagrilintide
Long-acting amylin analog. Interesting alone, far more interesting stacked with semaglutide as CagriSema.
GHK-Cu
Copper tripeptide. The best-evidenced cosmetic peptide there is — and injectable and topical are not interchangeable.
Pillar guide
Complete research guide — triple GIP/GLP-1/glucagon agonist: the Phase II readout that reset the upper bound of pharmacological body-weight reduction.
Trial readout
Cagrilintide + semaglutide fixed-dose combination. 20.4% mean body-weight reduction at 68 weeks — the largest pharmacological figure documented.
Guide
No retail price exists for an unapproved drug. How to normalise research-vial pricing to cost per mg, and why the cheapest sticker rarely is.
Explainer
No — not anywhere. Where the TRIUMPH Phase 3 programme stands, what it has to establish, and why an unapproved compound is sold openly.
Comparison
SURMOUNT-5 head-to-head — tirzepatide outperformed semaglutide on body-weight reduction with comparable adverse-event profile.
Class overview
Six compounds ranked two ways — by trial magnitude and by evidence quality — and why those two orderings disagree.
Mechanism
How a single 39-residue peptide engages two incretin receptors — and why the GIP arm changes the outcome.
FAQ
Indication, dosing schedule, GI tolerability, and where the compounded vs. branded distinction matters.
Pillar guide
The dual agonist that picked glucagon instead of GIP — ~19% in Phase 2, and a liver programme that may matter more than the obesity one.
Pillar guide
Complete research guide — FDA-approved dual GIP/GLP-1 agonist: SURMOUNT, SURPASS, and the field-defining body-weight endpoint curves.
Pillar guide
An engineered oxyntomodulin analog approved in China — the most biomimetic design in the class, and the lowest dual-agonist result.
Pillar guide
Pro-apoptotic peptide targeting adipose vasculature. Phase I kidney toxicity halted development — honest safety framing.
Scroll for more →
Pillar guide
Complete research guide — thymosin-β4 (1-43 fragment), actin binding, cell migration, and the cardiac-repair preclinical signal.
Trial readout
36 studies, 35 of them in animals, roughly 80% from one research group. What's claimed, what's behind each claim, and why the mechanism makes the breadth plausible.
Comparison
BPC-157 + TB-500 — the most-named peptide stack in the research community. Where the name came from, the mechanism, and what the evidence supports.
Class overview
The peptides most-studied for joint health, ranked by published evidence — and the standard-of-care context they're usually compared against.
Guide
No human dose-finding trial has ever been run. Why the animal doses do not convert, and why every online chart agrees with every other.
Explainer
No study has ever measured a BPC-157 before and after. The whole human record is three uncontrolled pilot reports…
Mechanism
VEGF-driven angiogenesis (BPC-157) + actin-monomer-driven cell migration (TB-500). Where the mechanisms converge.
FAQ
Reconstitution, half-life, route of administration, and what the literature does and doesn’t say about safety.
Pillar guide
Complete research guide — identity, multifactorial mechanism, the 35:1 preclinical-to-human ratio, FDA Cat 2 / WADA S0 status.
Trial readout
No controlled human safety data exists — three small uncontrolled reports is the entire record. What the animal work shows and what the FDA concluded.
Guide
Research sourcing guide — CAS 137525-51-0, the 503A Category 2 framing, real pricing benchmarks, and the BPC-specific red flags.
Guide
The most-stacked combination in research peptides. What the additive-mechanism case looks like and where it falls apart.
Scroll for more →
Pillar guide
Complete research guide — two molecules share the name: DAC vs. no-DAC half-life, the receptor pharmacology, and the missing human trials.
Trial readout
The honest before-and-after is a blood test, not a photo: IGF-1 restored to the young-adult range in 14 days in 1990s trials — and zero modern RCTs behind the transformation claims.
Comparison
The stabilized FDA-approved GHRH analog vs the discontinued original fragment — mechanism, half-life, evidence depth, regulatory status, and cost, compared honestly.
Guide
The rare compound here with a labelled dose rather than a reconstruction — and two correct numbers that cause most of the confusion.
Class overview
The growth-hormone axis ranked by evidence rather than reputation — and the hypertrophy outcome studies that mostly do not exist.
Explainer
Two small 2006 trials are the entire human safety record for CJC-1295. They report no serious reactions over 28 to…
Mechanism
Growth hormone secretagogue receptor pharmacology — why ipamorelin is more selective than GHRP-2 or hexarelin.
Pillar guide
Complete research guide — the selective ghrelin-receptor agonist: the GH peptide that doesn’t spike cortisol or prolactin.
Pillar guide
GHRH 1-29 analog — the 29-aa original used as Geref through 2008. Mechanism, evidence, and modern half-life context.
Pillar guide
Long R3 IGF-1 with N-terminal extension. Extended half-life, reduced IGFBP binding — honest cancer-biology framing.
Pillar guide
Synthetic GnRH decapeptide. Factrel discontinued; pulsatile-vs-continuous pharmacology, TRT-adjunct off-label.
Pillar guide
GHRP family — high GH-release potency, tachyphylaxis limitation, cardiac-protection preclinical signal.
Scroll for more →
Pillar guide
Complete research guide — Russian tetrapeptide aging program: Khavinson’s 1971 work, the telomerase claims, and the methodological gaps Western labs flagged.
Comparison
SS-31 + MOTS-c + NAD+ — three complementary mitochondrial mechanisms. Zero published controlled human trials of the combination.
Mechanism
SIRT1-7 deacetylase dependence on NAD+. The mechanism that anchors most of the popular longevity-market claims for the molecule.
Class overview
An honest review of the most-cited anti-aging peptides, anchored to peer-reviewed evidence rather than longevity marketing.
Trial readout
High-fat-fed mouse models show body-weight reduction without locomotor change. Sample size, dose, and translation limits.
Guide
No human trial has established a MOTS-c dose. The exact doses the mouse studies used, why mg/kg does not convert…
Explainer
MOTS-c activates AMPK and rises with exercise, which is where the exercise-mimetic framing comes from. What the…
Pillar guide
Complete research guide — 16-residue mitochondrial-encoded peptide: the "exercise mimetic" claim, the AMPK story, and the human-trial gap.
Pillar guide
Complete research guide — IV infusion, NMN, NR, NAM: the four ways to address declining cellular NAD+ and what the data actually supports.
Pillar guide
Complete research guide — selective NNMT inhibitor: the murine adipose-tissue signal, the mechanism, and the absent human trials.
Pillar guide
Complete research guide — mitochondria-targeted tetrapeptide, FDA-approved for Barth syndrome (Forzinity, Sept 2025).
Pillar guide
EDR tripeptide, Khavinson school. Russian preclinical work, mitochondrial proposals, thin Western RCT base.
Scroll for more →
Pillar guide
BPC-157 + TB-500 + GHK-Cu in one 70 mg vial. Per-constituent mechanism and evidence — and the honest gap: zero trials on the combined stack.
Guide
Two routes, two evidence bases. Topical has studied concentrations; injectable has zero human RCTs and a copper-load question nobody has looked at.
Class overview
An honest review of the strongest skin-health peptides, anchored to where the published evidence actually supports each route of administration.
Trial readout
A class of trials with positive descriptive findings but persistent methodological holes — and an FDA warning letter on IV use.
Mechanism
Type I/III procollagen mRNA upregulation in dermal fibroblasts. The biochemical case in dermal-aging (photoaging) research.
Explainer
Topical GHK-Cu has 12-week controlled cosmetic data in 71 women. Injectable GHK-Cu has no human trial at all. The…
Comparison
The route-of-administration debate. Why topical formulations dominate the published literature.
Pillar guide
Complete research guide — the master endogenous antioxidant: redox cycling, IV vs. oral controversy, and the skin-lightening evidence base.
Pillar guide
Complete research guide — endogenous copper tripeptide that declines with age, with the strongest topical signal in the catalog.
Pillar guide
Acetyl Hexapeptide-3 — the "Botox-like" SNAP-25 inhibitor. Topical anti-wrinkle evidence and cosmeceutical regulatory framing.
Pillar guide
Palmitoyl Pentapeptide-4 (KTTKS). Topical collagen-stimulating cosmeceutical with dermatology RCT base.
Class overview
The peptides most-studied for hair growth, ranked by published evidence — and honestly compared to minoxidil and finasteride.
Scroll for more →
Pillar guide
Complete research guide — Russian heptapeptide derived from tuftsin: GABAergic modulation, anti-anxiety claims, and the trial-quality picture.
Class overview
The peptides most-studied for sexual health, ranked by published evidence — and honest about PT-141's 40% nausea rate and Melanotan II's melanoma concerns.
Guide
Bremelanotide sourcing — Vyleesi prescription vs the third-party tested alternative, MC4R mechanism, and the melanotan II substitution risk.
Comparison
Russian heptapeptide pair — two neuropeptide classes. Institute of Molecular Genetics provenance, honest Western RCT framing.
Mechanism
The ACTH(4-10)Pro-Gly-Pro structure and how it engages BDNF signaling without the corticotropic side-effects of full ACTH.
Trial readout
The pivotal Phase III RECONNECT and PRISM studies — efficacy magnitude, adverse-event profile, and the FDA approval.
Explainer
Bremelanotide was developed as a nasal spray first. Blood-pressure rises and erratic uptake killed that route, and…
Pillar guide
Complete research guide — FDA-approved melanocortin agonist for HSDD: Vyleesi, the Phase III data, and the off-label dose-response.
Pillar guide
Complete research guide — the DSIP nonapeptide: 1977 isolation, the sleep-architecture literature, and the trial-quality gap.
Pillar guide
Complete research guide — Russian heptapeptide derived from ACTH(4-10): BDNF upregulation and the stroke-recovery indication.
Class overview
An honest review of the most-marketed sleep peptides, with explicit framing on where the published evidence supports the claims and where it doesn’t.
Class overview
A history of Russian neuropeptide research — tuftsin, ACTH(4-10), and the molecules that didn’t cross the Western methodological bar.
Scroll for more →
Pillar guide
Complete research guide — the C-terminal tripeptide of α-MSH: melanocortin signaling, the cleanest preclinical signal for ulcerative colitis.
Class overview
The peptides most-studied for immune support, ranked by published evidence — including the negative 2025 TESTS Phase III sepsis trial on Thymosin Alpha 1.
Trial readout
An elegant mechanism and the largest gap between marketing and published human evidence of anything in this library.
Guide
α-MSH C-terminal tripeptide. Anti-inflammatory without pigmentation, oral vs injectable forms for IBD research.
Mechanism
MC1R-independent anti-inflammatory action. Why a 3-residue peptide retains the parent molecule’s function.
Pillar guide
28-aa Zadaxin/Thymalfasin. 35+ country approval, FDA-unapproved in US. 2025 BMJ TESTS Phase III sepsis negative.
Pillar guide
KEDG tetrapeptide, Khavinson school. Proposed thymic function support; single-source-dominance flagged.
Pillar guide
KE dipeptide, Khavinson cytogen for immune cell proliferation. Honest evidence-base framing.
Class overview
An honest review of the most-cited gut-health peptides, anchored to peer-reviewed preclinical evidence for GI indications.
Trial readout
DSS-induced colitis models, oral and topical formulations, and the dose-response. Human trials still pending.
Guide
Approved in 30+ countries but not the US. Why the N-terminal acetyl group is the substitution point to check.
Scroll for more →
Guide
What "third-party verified" means in 2026: HPLC purity floor, per-lot third-party COA, mass-spec identity, and the documentation chain that defines the category.
Explainer
The 50-amino-acid line that separates a peptide from a protein. Why the distinction matters for half-life, synthesis, and oral bioavailability.
Class overview
The peptides with the lowest entry barriers for new researchers — ranked by safety, ease of use, and evidence depth.
Guide
What 'peptides for sale' actually means, why the prices scatter so wildly, and the one request that separates a seller who tests from one who doesn't.
Guide
A 2026 buyer's guide — the eight criteria, real price-per-mg ranges by class, the regulatory framing, and a 30-minute vendor verification checklist.
Guide
Frozen vs. refrigerated vs. room-temperature stability windows. Lyophilized vial life, post-reconstitution life, and freeze-thaw cycle limits.
Guide
Most raw material is synthesised in China, including what Western brands relabel. What buying direct actually changes — and what it doesn't.
Guide
Which peptides sit on the WADA prohibited list, which categories they fall under, and the in-competition vs. out-of-competition distinction.
Guide
An 8-criterion evaluation framework — purity, COA transparency, lab partners, returns — applied honestly across the major US vendors.
Guide
There is no retail counter for research peptides, and the reason is structural. What genuinely is available locally, and what isn't.
Guide
Complete legal framework — RUO under 21 CFR §809.10, 503A categories, WADA prohibition, customs, and the seller-vs-buyer asymmetry.
Guide
Why 0.9% benzyl alcohol is the standard diluent for peptide vials — and what the sterile-water and saline alternatives actually do.
Scroll for more →
Research peptides are sold legally in the United States as research chemicals, labelled research use only and not for human consumption. That labelling is the legal basis for the sale — it is not a formality. Suppliers cannot lawfully market them for human use, make therapeutic claims, or provide dosing instructions. Buying them for laboratory work is legal; a supplier telling you how to inject one is a sign that supplier is not operating within the rules.
One thing above all others: a third-party certificate of analysis whose batch number matches the vial you were sent. Not a generic PDF for the product line, not an in-house QC sheet, not a purity number printed on the label. Everything else — domestic shipping, responsive support, clean packaging — is table stakes that a bad supplier can fake just as easily as a good one.
Usually it means HPLC peak area: the share of UV-absorbing material eluting as the target peak. It says nothing about what the other 1% is, and nothing about whether the main peak is the peptide you ordered — that takes mass spectrometry. A purity figure without an identity method behind it is half a claim. Look for HPLC and MS on the same report.
Substantially, and that gap is the entire reason the research-peptide market exists. A compounding pharmacy or telehealth clinic is selling a prescription drug with clinical oversight, pharmacy overhead, and liability attached. A research supplier is selling a labelled reference compound with none of those things. You are not comparing two prices for the same product.
Chemically they can be identical — same sequence, same molecular weight, sometimes the same contract manufacturer upstream. What differs is everything around the molecule: sterility assurance, endotoxin testing, fill-finish under GMP, batch traceability, and a regulator who will act if a lot fails. Those controls are most of what a prescription costs.
Retatrutide, by a wide margin — a triple GIP/GLP-1/glucagon agonist still in Phase 3 trials with no approval anywhere. Its Phase 2 weight-loss results were the largest reported for any pharmacological agent, which is why demand for it runs far ahead of its evidence base.
