# Integrative Peptide — Metabolic & Weight Research research peptides > Integrative Peptide is a data-forward index of four metabolic research peptides — AOD-9604, retatrutide, semaglutide, and tesamorelin — read by study design and effect size. A digest, not a vendor or clinic. A numbers-forward reading of four metabolic research peptides — how each one is built, what its trials actually measured, and how far the evidence honestly reaches. ## The short version Integrative Peptide reads four metabolic and weight-management research peptides the way an analyst reads a stack of trial reports: by study design, sample size, effect size, and how far the evidence actually reaches. The four compounds are **AOD-9604, retatrutide, semaglutide, and tesamorelin** — four different ways of nudging the body's metabolism, tested with very different amounts of rigor and sitting at very different stages of regulatory maturity. Retatrutide leads this desk because it currently posts the largest published weight-loss numbers of the four — a -24.2% mean body-weight change in its pivotal Phase 2 trial [9] — though it remains investigational. Semaglutide has the deepest, broadest evidence base and the widest approved-indication footprint. Tesamorelin has a narrow but solid approval. AOD-9604 is the honest outlier: a clean mechanism in mice that did not clear a human efficacy bar. None of this is medical advice, and no dose is recommended anywhere on this site. ## How this desk reads four peptides The organizing idea here is **the metabolic research peptides in one integrated picture**: rather than covering one compound in isolation, this desk puts four different receptor-mechanism strategies side by side so a reader can see what each one actually contributes. [AOD-9604](/aod-9604) and [tesamorelin](/tesamorelin) both trace back to the growth-hormone axis, working in opposite directions. [Semaglutide](/semaglutide) and [retatrutide](/retatrutide) both work through the GLP-1 receptor, with retatrutide adding two more receptor targets — GIP and glucagon — on top. The evidence-maturity gap between these four is the more interesting story than the mechanism alone. Semaglutide has over a decade of large-scale trial data across multiple indications [14][15][16]. Retatrutide's Phase 2 program is smaller but has already produced the single largest weight-loss figure on this desk [9]. Tesamorelin's evidence is dense but confined to one approved use [18]. AOD-9604's story is the cautionary one: rodent data that looked convincing [4][5], paired with a human efficacy trial that did not confirm it. Reading all four together, rather than any one alone, is what this desk is built to do — use the [comparison page](/compare) for the direct side-by-side. ## What are research peptides? Peptides are short chains of amino acids, the same building blocks that make up proteins, just far smaller. The four compounds on this desk fall into two families. AOD-9604 and tesamorelin are growth-hormone-axis peptides — one a fragment of growth hormone itself, the other a signal that tells the pituitary gland to release more of it. Semaglutide and retatrutide are incretin-class peptides — synthetic analogues of gut hormones (GLP-1, GIP, and, for retatrutide, glucagon) that the body normally releases after eating, chemically modified with fatty-acid side chains so they last long enough in the bloodstream for once-weekly dosing instead of the few minutes native hormones survive. Two of the four — semaglutide and tesamorelin — are FDA-approved prescription medicines for specific indications. Retatrutide is investigational, studied only in registered clinical trials. AOD-9604 was never approved for any use; its anti-obesity development program was discontinued after failing to demonstrate efficacy. Research-grade material sold outside an approved product or a registered trial falls outside the evidence base this desk describes, and carries documented quality and identity risks. Wherever this site reports a dose, it reports the dose a study used — never a recommendation for a person. ## A note on how this desk reads the numbers Every figure on this desk is reported at the scale it was actually measured: a percentage, a sample size, a duration, a confidence interval. Retatrutide's -24.2% weight change came from 338 people over 48 weeks in a Phase 2 trial [9] — a real, large, well-designed study, and also one stage short of the confirmatory Phase 3 data that supports an approval. Semaglutide's -14.9% weight change came from a larger, later-stage trial with a decade of surrounding evidence behind it [16]. Tesamorelin's evidence is smaller in absolute participant count but concentrated and consistent within one narrow, approved indication [18]. AOD-9604's evidence is the most lopsided of the four: a large, successful safety program paired with an efficacy result that did not reach significance — a useful reminder that a defensible mechanism in animals is not the same thing as a proven benefit in people. This desk reports all four at their actual evidentiary weight, not at the weight the marketing around them sometimes implies. --- Integrative Peptide reads the primary literature so the numbers can carry the argument — an independent research index, not a clinic, a vendor, or a source of medical advice.