Peptides: overview

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.

MOTs-C and Epitalon both get sold as longevity peptides. They face the FDA's PCAC review on consecutive days in July for completely different indications. Here is what their two very different evidence standards actually look like.

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.

GHK-Cu shows up in every premium anti-ageing serum and on every injectable peptide menu. The foundational science is real, mostly from one researcher across forty years, and the one randomised human trial of GHK-Cu skincare found no objective benefit. Here is what the evidence actually says.

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.

Sermorelin and tesamorelin hit the same pituitary receptor and pull the same upstream lever on growth hormone. One had two FDA approvals and lost them for business reasons. The other still has one, for a population almost no buyer belongs to. Same mechanism, different paperwork.

CJC-1295 and ipamorelin get sold side-by-side as the growth-hormone protocol — one lifts the baseline, the other adds the pulse. Two molecules, two different mechanisms, two human evidence files that almost don't overlap. Here is what the published data actually separates them on.

BPC-157 and TB-500 get sold side-by-side as the injury-recovery peptide stack. Two different proteins, two different evidence bases, two different gaps. Here is what the published data actually says — and where the July 2026 FDA review treats them as one regulatory question.

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.

MOTS-c is sold as exercise in a vial — a peptide that works the same pathways your body uses to get fit and stay young. Here is what the research actually shows, what the human evidence looks like, and where the July 2026 FDA review fits.

AOD-9604 was built on a clean mechanistic premise — the fat-burning piece of growth hormone, isolated from the rest. The mouse work was real. The human Phase II results disappointed. The molecule pivoted to joints, then to muscle preservation in the GLP-1 era. Here is the actual story.

Thymosin Alpha-1 has the deepest human trial record of any peptide on the longevity menu, including a 2025 multicentre sepsis trial in BMJ. The populations studied are not the ones buying it. Here is what the evidence shows and where the regulatory line actually falls.

TB-500 has a reputation for pulling tendons back from chronic pain. The underlying protein is real. The tendon-specific evidence is thinner than the forums imply. Here is what the research actually shows, what nobody has tested in a human tendon, and how the July 2026 FDA review fits.

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 MOTS-c — the mitochondrial-derived peptide studied for metabolic regulation and exercise mimicry, what the preclinical and early human data show, and its position on the PCAC July 23–24 2026 docket.

Science-journalism overview of PT-141 (bremelanotide) — the melanocortin agonist with regulatory approval for hypoactive sexual desire disorder in women, its mechanism, clinical evidence, and the off-label interest driving compounding demand.

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.

Science-journalism analysis of tesamorelin — the GHRH analog with a specific FDA drug approval for HIV-associated lipodystrophy, what off-label interest means, and why compounding restrictions apply.

Science-journalism overview of Thymosin Alpha-1 — the thymic peptide with extensive clinical development history in immunology, its evidence base in infections and cancer, and why it occupies a distinct regulatory category in the United States.

An honest read on BPC-157 — what hundreds of animal studies actually show, what the human evidence really is (two small uncontrolled pilots), and where the compound sits ahead of the FDA's July 2026 compounding review.

BPC-157 has a reputation for rebuilding tendons and joints. Almost all of that reputation rests on animal studies. Here is what the injury-recovery evidence actually says, where the human gap sits, and why the July 2026 FDA review matters.