Research peptide guides

What a peptide is, how it differs from a protein, why sequences are studied in vitro, and what the phrase “research grade” does and does not describe.

How UK medicines law treats research peptides, what an absent MHRA marketing authorisation means, and where research supply differs from a medicine.

The specifications worth comparing between suppliers, the ones that mean nothing, and the handling checks that decide whether material arrives usable.

Research-use-only is a basis of supply, not a disclaimer. What the designation covers, what it excludes, and where responsibility sits with the purchaser.

Tirzepatide is a 39-residue dual agonist at the GIP and GLP-1 receptors. What that means and how the molecule resists breakdown.

Cagrilintide is a long-acting amylin analogue acting at the amylin and calcitonin receptors — a different receptor family from the incretin agonists.

Ipamorelin is a pentapeptide ghrelin receptor agonist, studied for its selectivity relative to earlier growth hormone secretagogues.

Tesamorelin is a stabilised analogue of growth hormone-releasing hormone, acting at the GHRH receptor rather than the ghrelin receptor.

MOTS-c is a 16-residue peptide encoded in mitochondrial DNA rather than the nuclear genome — an unusual origin that is the interesting part.

GHK-Cu is a three-residue peptide holding a copper ion in a coordination complex. Why the copper is part of the molecule, not an additive.

Melanotan II is a cyclic analogue of α-MSH that activates melanocortin receptors non-selectively. Why the non-selectivity is the defining feature.

Semax is a heptapeptide built on the ACTH(4–10) fragment with a Pro-Gly-Pro tail — an ACTH derivative with the hormonal activity removed.

Selank is a heptapeptide built on the immune-related tetrapeptide tuftsin with a stabilising Pro-Gly-Pro tail. What that origin implies.

BPC-157 is a 15-residue synthetic peptide corresponding to a partial sequence of a protein found in gastric juice. What is and is not established.

TB-500 is a synthetic fragment of thymosin β4, usually the actin-binding region. Why the name is ambiguous and what to confirm before ordering.

CJC-1295 is a 29-residue GHRH analogue sold in two chemically different forms. The DAC and no-DAC versions differ by 279 Da and by days of half-life, and suppliers list both under one name.

Kisspeptin-10 is the shortest active fragment of the KISS1 gene product, acting at the receptor KISS1R. Unusually for this category, it is under active clinical investigation.

Epithalon is a four-residue synthetic tetrapeptide, Ala-Glu-Asp-Gly, developed in St Petersburg as an analogue of a pineal extract. Also spelled Epitalon.

DSIP is a naturally occurring nonapeptide isolated from rabbit cerebral venous blood in the 1970s. The name records the circumstances of its discovery, not a demonstrated mechanism.

Pinealon is a three-residue synthetic tripeptide, Glu-Asp-Arg, from the same St Petersburg programme as Epithalon. At 418 Da it is among the smallest peptides sold.

What "peptide bioregulator" means, where the Khavinson short peptides came from, and how Epithalon and Pinealon compare on sequence, size and evidence.

The Glow blend combines GHK-Cu, BPC-157 and TB-500 in one cartridge. What each component is, and what a fixed-ratio blend can and cannot be used for.

KLOW combines GHK-Cu, BPC-157, TB-500 and KPV in one cartridge — the Glow components plus a fourth. What KPV adds, and what the format constrains.

“Wolverine stack” is the informal name for BPC-157 paired with TB-500. Where the name came from, what it does not standardise, and what each component is.

One adds the glucagon receptor to the other’s two. What that difference in receptor coverage does and does not imply.

Unrelated parent molecules, and one has a measurable target while the other has none. Why that asymmetry matters more than any similarity.

Both are Russian-developed heptapeptides with the same stabilising tail, built on completely unrelated fragments. What that shared design implies.

These two are studied in overlapping contexts but act on unrelated receptor families. Why they are not alternatives to each other.

Searches for the pairing outnumber searches for either compound alone. They act at two different receptors, one governing pulse size and the other pulse timing.

KLOW is the Glow blend plus KPV. How the two compare on components, total peptide and concentration, and where the Wolverine and GHK-Cu pens fit.

Both sit upstream of growth hormone release, at different receptors. How tesamorelin and ipamorelin differ in target, structure, design and supply.

Why 2–8 °C, why light matters, why not to freeze a solution, and why cold-packing covers transit only. The reasoning behind each condition.

What bacteriostatic water is, what the benzyl alcohol in it does and does not do, and why the diluent is only part of what governs stability.

The dial meters volume, not mass — so what one increment delivers depends entirely on the concentration in that cartridge.

One removes the reconstitution step, the other keeps control of concentration and a longer shelf life. An honest account of both sides.

Our blends publish the split, so per-component concentrations are known. What a fixed ratio does and does not cost you, and when to buy separately.

Three diluents for reconstituting lyophilised peptides. What each one is, when each is used, 3 ml or 10 ml, and how volume sets concentration.

All ten pre-mixed peptide pens in one table: compound, total mass and concentration, single compounds and blends, and how to choose between them.