Mechanism explainers

Three peptides under FDA review have animal-model anti-inflammatory evidence: KPV, BPC-157, GHK-Cu. Each engages the inflammatory cascade at a different point. None has a controlled human trial in an inflammatory indication. Here is where the three files diverge.

AOD-9604 was built on a structural conceit — keep the fat-loss part of growth hormone, throw away the growth-promoting part. The Phase IIb trial that tested whether the conceit held in humans did not meet its primary endpoint. Here is what that meant and what it would take to re-open the file.

The thymus trains your T-cells. It shrinks from a small fist to a patch of fat by your fifties. Thymosin α-1 is the most-studied peptide derived from it. Here is what the immune connection is, and where the largest sepsis trial just rewrote the file.

Most peptide articles assume you already know how to read a peptide study. The skill is not innate, and the errors cluster in five specific places. Here are the five questions to ask of any cited paper before letting it carry weight in a prescribing or buying decision.

Three peptides under FDA review have animal-model evidence touching collagen biology — BPC-157, GHK-Cu, and TB-500. The mechanism story varies per peptide. The human evidence does not. Here is what collagen is and where the prescribing files diverge.

The route a peptide gets dosed by changes its evidence base more than most readers realise. Oral, subcutaneous, and intranasal each ask different questions of the molecule. Here is why the route a study used often does not match the route the product is sold under.

The HPA axis is the body's stress-response chain — hypothalamus, pituitary, adrenal cortex, cortisol. Two Russian-tradition peptides get sold for stress and cognition. Neither sits where the marketing implies. Here is what each actually engages.

Of every peptide on the longevity menu, GHK-Cu is the only one sold under a name that names its metal cofactor. The copper does the work. Here is what a copper peptide actually is, what the human evidence shows for topical use, and where the injectable form sits in the FDA's second-wave review.

Telomeres are repetitive DNA caps at chromosome ends; they shorten with cell division. Here is what telomerase actually does, what the human data shows, and where epitalon — the peptide attached to this story — sits in the July 2026 FDA review.

Two peptides on the July 2026 FDA review docket — BPC-157 and TB-500 — rest their entire animal mechanism story on the same biology: new blood-vessel growth into damaged tissue. Here is what that means, where the human evidence sits, and the open question angiogenesis always raises.

CJC-1295, ipamorelin, sermorelin, and tesamorelin all sit in the growth-hormone-secretagogue class. They are routinely confused for each other. Here is the mechanism, the human evidence on each, and the four separate regulatory files behind the shared label.

Mitochondrial-derived peptides are short signals encoded inside the mitochondrial genome — a class your textbooks didn't have ten years ago. Here is what they are, what the animal mechanism work shows, and where MOTs-c sits in the July 2026 FDA review.

BPC-157 is a fifteen-amino-acid fragment of a gastric protein. The proposed mechanism — angiogenesis, nitric oxide signalling, cytoprotection — comes almost entirely from animal models. Here is what the mechanism is, where the evidence sits, and the FDA review now scheduled for July 2026.

Science-journalism overview of GHK-Cu — the copper-binding tripeptide studied for wound healing and skin biology, what the preclinical and clinical literature shows, and its regulatory position in 2026.

Peptides are short chains of amino acids that act as biological signals. Some are drugs you already trust. Some are research chemicals nobody has cleared for human use. The difference matters more than the word does.

The Pharmacy Compounding Advisory Committee is the FDA panel deciding which peptides US compounding pharmacies will be allowed to dispense by prescription. Two meetings, twelve peptides, and a vote that is not the same as a drug approval.

Epitalon is a four-amino-acid peptide studied for telomerase induction in cultured cells and lifespan in mice. The FDA is reviewing it on July 24 for an insomnia indication. Here's what the evidence actually shows.

Semax is sold as a nootropic and was developed in Russia as a stroke treatment. Here's what the structural precision requires, what the mechanism shows in animals, and why Russian stroke evidence is not Western nootropic evidence.

Selank has been used in Russian psychiatric practice for over a decade as an anxiolytic with no sedation and no dependence. Here's what the comparative trials show, why the Russian evidence base is real but limited, and what Western replication would need to look like.

Ipamorelin's selling point is what it doesn't do — no cortisol spike, no prolactin spike, just a clean ghrelin-receptor GH pulse. Here's what the animal work actually shows, why the one Phase 2 trial was null, and what that means for the stack marketing.

CJC-1295 is the long-acting GHRH analog the muscle-and-aging marketing keeps pointing at. Here's what's actually known, what the DAC-versus-no-DAC question hides, and why one well-run Phase 1 trial in 2006 is still doing all the work.

Sermorelin had a real FDA approval, lost it for business reasons, and lives on as the anti-aging clinic's GH peptide of choice. Here's what the human evidence actually shows, what gets quietly substituted in its name, and where the longevity case is honest.

Selank and Semax get sold side-by-side as cognitive performance peptides. Neither was built for that. Here is what the actual evidence shows, where the Russian-literature replication gap sits, and how the July 2026 FDA review splits the two peptides apart.

Science-journalism overview of CJC-1295, a synthetic GHRH analog studied for sustained growth hormone release — what animal and limited human data show, and its regulatory status in 2026.

Science-journalism overview of DSIP — the nonapeptide associated with sleep regulation and stress modulation, its evidence base across decades of research, and its position on the PCAC July 23–24 2026 docket.

An independent science-journalism review of ipamorelin research — how this selective GH secretagogue works, what the preclinical and limited clinical literature shows, and its current regulatory standing.

Science-journalism overview of Selank — a Russian-developed heptapeptide studied for anxiety reduction and cognitive effects, its evidence base, and why it sits outside both the July 2026 and February 2027 PCAC dockets.

Science-journalism overview of Semax — the ACTH-derived heptapeptide studied for neuroprotection and cognitive enhancement, what preclinical and limited human data show, and its position on the PCAC July 2026 docket.

Science-journalism overview of sermorelin — the synthetic GHRH fragment with the most extensive clinical development history in the GH secretagogue class, its published human evidence, and its current regulatory standing.