44 compounds · 36 comparisons · live prices
Research peptides, priced and explained.
Shop the Nordapep catalogue with the evidence, regulatory status and price per mg for every compound beside it, plus the comparisons, calculators and guides researchers use most.
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Price per mg →Lowest price per mg across in-stock sizes. For in vitro research only.
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Batch-tested research peptides
Live prices from the Nordapep catalogue, each with a Certificate of Analysis per batch. Open the wiki profile to check the evidence before you buy.
Live Nordapep prices, refreshed hourly.
The wiki
Everything you need to research a peptide
Search the whole site or jump straight into the reference.
Head to head
Most-searched peptide comparisons
Each comparison sets two compounds side by side on mechanism, structure, evidence and price, then explains what actually separates them.
The core difference is receptor coverage. Semaglutide acts on the GLP-1 receptor only; tirzepatide acts on both the GIP and GLP-1 receptors. Both are fatty-acid-modified for a long half-life and both are approved medicines, so both sit at the top of our evidence scale.
Read the comparison →Retatrutide adds glucagon-receptor activity to the GIP and GLP-1 activity that tirzepatide already has. That third receptor is the whole story of the comparison.
Read the comparison →This pairing spans the whole incretin story: one receptor versus three. Semaglutide is the established single-receptor medicine; retatrutide is the investigational triple agonist.
Read the comparison →These are often mentioned together but are unrelated molecules. BPC-157 is a 15-residue peptide derived from a gastric-juice protein. TB-500 is a fragment of thymosin beta-4, an actin-regulating protein.
Read the comparison →They act on two different pituitary receptors. CJC-1295 is a GHRH analogue acting at the GHRH receptor; ipamorelin is a ghrelin-receptor agonist. That is why they are so often studied together rather than instead of each other.
Read the comparison →PT-141 was derived from melanotan II. The key difference is selectivity: melanotan II activates several melanocortin receptors broadly, while PT-141 acts more selectively on central receptors, mainly MC4R.
Read the comparison →Both are Russian-developed heptapeptides that share a stabilising Pro-Gly-Pro tail, but their parent sequences differ. Semax comes from ACTH(4-10) and is studied for neurotrophic signalling; Selank comes from tuftsin and is studied for stress-response and GABAergic pathways.
Read the comparison →Both are acylated GLP-1 analogues that act on the GLP-1 receptor only, and both are approved medicines. The difference is in the engineering: semaglutide has a different N-terminal substitution and a longer fatty-diacid linker, which gives it a half-life of about a week against roughly 13 hours for liraglutide.
Read the comparison →These two act on different hormone systems. Semaglutide mimics GLP-1 and activates the GLP-1 receptor. Cagrilintide mimics amylin and activates amylin and calcitonin receptors. Both are acylated for a half-life of about a week.
Read the comparison →The index
Most-researched compounds
Retatrutide
Investigational GIP, GLP-1 and glucagon triple agonist
Tirzepatide
Dual GIP and GLP-1 receptor agonist
Semaglutide
Long-acting GLP-1 receptor agonist
BPC-157
15-amino-acid peptide studied in cytoprotection models
TB-500
Synthetic fragment of thymosin beta-4
GHK-Cu
Naturally occurring copper-binding tripeptide
Free tools
Calculators and finders for the bench
No sign-up and nothing stored. Everything runs in your browser.
Peptide molecular weight calculator
Calculate monoisotopic and average mass, net charge, pI and extinction coefficient from a sequence.
Open tool →Certificate of Analysis checker
Work through what a credible CoA should show and test the reported mass against the theoretical mass.
Open tool →Order cost planner
Find the cheapest mix of Nordapep vial sizes for the total quantity your study needs.
Open tool →Stock solution & dilution calculator
Work out stock concentration, serial dilutions and weigh-out masses for research solutions.
Open tool →Peptide finder
Answer five quick questions to find compounds by research area, evidence, status and size.
Open tool →Not sure where to start?
Find a compound by area, evidence and status
Answer a few quick questions and the peptide finder points you to the reference pages that fit. It filters the library; it never recommends a use.
Learn
Guides for researchers
How to choose a research peptide supplier: a UK buyer's checklist
Ten checks to run before ordering research peptides: batch-matched CoAs, independent testing, transparent pricing, clear labelling and honest claims.
Peptide price per mg: how to compare vials properly
Why price per vial misleads, how to calculate price per mg and net-peptide price, and how pack sizes change what you really pay.
HPLC vs mass spectrometry: what each test tells you about a peptide
HPLC measures purity, mass spectrometry confirms identity. Why a CoA needs both, what each cannot detect and how to read the results.
Browse
By research area
Metabolic & incretin research
11GLP-1, GIP, glucagon and amylin receptor agonists, the most heavily studied peptide class of the decade.
Growth-hormone axis
8GHRH analogues, ghrelin-receptor agonists and IGF-1 analogues used to study pituitary signalling.
Tissue repair & recovery
4Peptides studied in cell-migration, cytoprotection and wound-model research.
Skin & matrix biology
1Copper-binding and signal peptides studied in cell culture and used as cosmetic ingredients.
Melanocortin receptors
4Melanocortin agonists studied for pigmentation and central signalling pathways.
Neuro & longevity research
5Short regulatory peptides studied in neurotrophic, sleep, stress-response and cellular-ageing models.
Immune & inflammation research
3Antimicrobial, anti-inflammatory and thymic peptides studied in immune-cell models.
Mitochondrial & metabolic ageing
3Mitochondria-derived and mitochondria-targeted compounds studied in cellular energy research.
Reproductive & neuroendocrine
5Hypothalamic and pituitary signalling peptides such as kisspeptin, GnRH and oxytocin.
Our edge
An evidence scale, not hype
Most peptide sites call everything 'clinically studied'. We rate every compound on what the published literature actually contains, and show the rating next to the price.
- 5Approved drug, phase 3 trialsSemaglutide, Tirzepatide, PT-141, Liraglutide, Tesamorelin, Afamelanotide, Setmelanotide, Oxytocin, Exenatide, Pramlintide, Teriparatide, Abaloparatide, Teduglutide, Octreotide, Leuprolide
- 4Late-stage human trialsRetatrutide, Cagrilintide, Thymosin alpha-1, SS-31, Survodutide, Mazdutide
- 3Early human trialsLL-37, Kisspeptin-10, Sermorelin, GHRP-2, Gonadorelin, ARA 290
- 2Mostly animal and in vitroBPC-157, GHK-Cu, Semax, Selank, Melanotan II, CJC-1295, Ipamorelin, GHRP-6, MOTS-c, Hexarelin, AOD-9604, Humanin
- 1Limited, preclinical or single-groupTB-500, Epithalon, IGF-1 LR3, DSIP, KPV
Where to buy
Why we send researchers to Nordapep
Comparing compounds is only half the job. The other half is knowing the vial contains what the label says. Nordapep publishes batch documentation for every compound it sells.
Browse the Nordapep catalogue →Each batch reference on the label matches its CoA, so you can check what is in the vial.
Enter the batch reference from your vial into Nordapep's batch-verification tool.
Purity is reported by RP-HPLC, the standard method for peptides of this size.
Bundled stacks for common comparisons, plus tiered pricing for volume orders.
FAQ
Questions researchers ask
What is peptide.wiki?
A reference and comparison site for research peptides. Every compound page sets out structure, receptor targets, an evidence rating, regulatory status and current Nordapep pricing, and any two or three compounds can be compared side by side.
Who publishes peptide.wiki?
The team behind Nordapep. We say so on every page, and every buy link goes to Nordapep. The evidence ratings follow a published method that does not depend on what we sell.
How are the evidence ratings decided?
On a five-point scale from approved medicines with phase 3 trials (5) down to preclinical or single-group literature (1). The full rubric is on the methodology page.
Are these peptides for human use?
No. The compounds are described and supplied for in vitro laboratory research only. Some share a name with approved medicines, but research-grade material is not a medicine.
How current are the prices?
Prices are pulled from Nordapep's live catalogue and refreshed hourly. Always confirm the final price on Nordapep before ordering.