Author
Founder and Editor
Tristen Ta is the founder and editor of PeptidesInfo, an independent publication that examines peptide research, regulatory status, evidence quality, and emerging applications for a general audience.
Not a licensed clinician; does not provide medical review.
A certificate of analysis usually shows an HPLC purity percentage and a mass-spectrometry result. They measure different things, and neither one alone tells you the vial holds the molecule on the label.
Purity and identity are chemistry. Endotoxin and sterility are biology, and they are measured by completely different tests that most peptide certificates of analysis never ran.
Peptides break down through a small set of well-characterised chemical reactions. Here is what deamidation, oxidation, hydrolysis and aggregation actually are, why temperature and moisture drive them, and what a real stability study measures.
Synthetic peptides are sold by gross weight, but part of that weight is salt and water, not peptide. Here is what net peptide content means, why HPLC purity does not measure it, and how the gap is actually quantified.
One target, two targets, three targets: semaglutide, tirzepatide and retatrutide represent three generations of the same drug idea. Here is what their landmark trials actually reported, what can and cannot be compared across them, and where each stands with regulators.
NAD+ is sold as drips, shots and supplements for energy and aging. Precursor pills really do raise NAD+ in blood - but the benefit trials are mostly small and mixed, and direct NAD+ infusions have almost no published human data. Here is the honest picture.
'Peptide therapy' is a marketing umbrella, not one treatment. Some peptides under it are FDA-approved and highly effective; others are unproven research chemicals. Here is how to tell the benefits apart.
Ipamorelin is sold for muscle, fat loss and anti-aging by raising growth hormone. It does raise GH cleanly in studies - but raising GH is not the same as building muscle or reversing aging. Here is the honest split.
BPC-157 is sold for gut, tendon and joint healing, and users report fast recovery. The animal data is genuinely interesting - but there are still no completed human efficacy trials. Here is the honest split.
New to peptides? Skip the hyped research chemicals and start where the human evidence is strongest - GLP-1s for weight, collagen for skin and joints, PT-141 for low desire. Here is the honest beginner's map.
Thymosin alpha-1 is one of the few peptides with genuine human trial data. It is approved in 35+ countries as Zadaxin - but not in the US. Here is what it is used for and what the research actually shows.
Sermorelin nudges your body to make its own growth hormone. It was once FDA-approved for children's growth, and is now used off-label for anti-aging and body composition. The direct human evidence is limited but promising. Here's the honest read.
Retatrutide is the next-generation weight-loss drug that hits three hormone targets at once. Trial results are striking, but it is not FDA-approved and cannot be legally compounded. Here is what the evidence actually shows.
Peptides and SARMs get lumped together online, but they are different molecules with very different safety and legal profiles. Here is the honest comparison, with what the FDA and the evidence actually say.
Copper peptides and biotinoyl tripeptide-1 are sold widely for hair loss. The supporting studies are mostly cells and animals. Here is what exists in humans, and how it compares with the two treatments that have decades of trial data.
Better sleep and more energy are standard peptide selling points. No growth-hormone secretagogue has been tested with sleep laboratory measurement, and the one peptide with a large sleep trial works by a completely different route.
Most of the peptides discussed for performance and recovery are prohibited in sport at all times. Here is exactly which WADA category each falls under, which are not listed, and why 'not listed' is not the same as safe or legal.
MOTS-c is a peptide your own mitochondria make - it rises with exercise and improves metabolism and healthspan in mice. It's genuinely fascinating science. But the evidence for taking it is still preclinical. Here's the honest read.
Melanotan II is an unapproved peptide injected or sniffed to get a tan. It does darken skin - but it is linked to changing moles and reported melanomas, and it is not approved anywhere. Here is what the evidence shows.
Kisspeptin is a natural hormone-controlling peptide being tested for low sex drive - and unlike most 'libido peptides,' it has genuine human trials. It's promising and well-tolerated, but still investigational. Here's the honest evidence.
Copper peptides and topical retinoids are both sold for photoaged skin. One has several small trials, the other decades of large ones. What each has actually demonstrated, and the head-to-head trial nobody has run.
"FDA-approved" and "works" are different questions, and conflating them is how most peptide confusion starts. This explains the two independent axes — regulatory status and evidence level — with four worked examples.
Fake and counterfeit versions of semaglutide and tirzepatide are being sold online, sometimes with made-up pharmacy labels. Here is how the FDA says to recognize them and buy safely.
Compounded semaglutide is not the same as Ozempic or Wegovy. It is not FDA-checked, the shortage that made it common is over, and the FDA has linked it to dosing errors and hospital visits. Here is the plain version.
Cerebrolysin is a brain-peptide mixture approved in many countries for stroke and dementia. It has real randomized trials - but a Cochrane review found the evidence weak and the benefits possibly too small to matter. Here's the honest read.
Peptides are a big deal in the healing and recovery world - BPC-157, TB-500, GHK-Cu, collagen. Some have real human data, some are strong in animals only. Here is each one, graded for wound healing and tissue repair.
For women, a few peptides have genuine evidence - collagen for skin and joints, GLP-1s for weight, PT-141 for low desire. Many others are marketed on hope. Here is the honest, goal-by-goal guide.
One peptide for sexual health is genuinely FDA-approved: PT-141 (Vyleesi), for low desire in premenopausal women. It works on desire in the brain - with real caveats. Here is what the evidence supports, and what the online marketing skips.
For men, the peptides with real evidence are specific: GLP-1s and tesamorelin for fat, PT-141 and kisspeptin for libido. The muscle and 'anti-aging' peptides are hyped hardest and proven least. Here's the honest guide.
Sore knees, stiff joints, cranky tendons - peptides are everywhere in the recovery world. Collagen has the best human evidence for joint comfort; BPC-157 and TB-500 are promising but mostly animal data. Here is what helps, graded.
'Immune peptides' are sold everywhere, but only one has real human trials: thymosin alpha-1. Here is what actually has evidence for supporting the immune system - and what is just marketing.
When people ask about peptides for gut healing, they almost always mean BPC-157. The animal evidence for gut repair is genuinely strong and consistent - the human evidence is still limited. Here is the honest picture.
Semax and Selank are the 'nootropic peptides' sold for focus, memory, and calm. They have real clinical use - in Russia. The Western evidence is thin and mostly unreplicated. Here is the honest picture.
'Anti-aging peptides' are marketed hard, but the evidence is uneven. Collagen has the best (still modest) human data; most growth-hormone and 'longevity' peptides are weaker than the ads suggest. Here is each one, graded.
Peptides and anabolic steroids are lumped together in gym talk, but they are different types of molecule with different legal status. Peptides are amino-acid chains; anabolic steroids are controlled substances. Here is the clear difference.
AOD-9604 is sold as a fat-loss peptide - a fragment of growth hormone. It works in mice, but its one large human trial failed to beat placebo and was never published. Here is the honest evidence.
Growth-hormone peptides are sold almost entirely on muscle claims. No controlled trial has measured muscle with them. The one peptide with positive lean-mass data is the one nobody markets for it.
Appetite changes in weeks, weight declines for over a year before plateauing, and cardiovascular benefit separates over months. Here is when each GLP-1 benefit appeared in the trials that measured it.
Whether a peptide is worth it depends on four things: what benefit is proven, in whom, for how long, and whether the effect lasts after you stop. Here is that framework applied to every peptide we cover.
Two peptides produce large, well-documented weight loss in randomised trials. Several others are marketed for fat loss with no outcome data at all. Here are the numbers, the timeframes, and what happens when you stop.
Skin is one of the few areas where peptides have real human trials. Topical copper peptides and oral collagen both improve measurable skin properties — modestly, over weeks, in studies mostly funded by the people selling them.
Recovery is the most-marketed peptide benefit and the least proven. This separates the recovery claims with human trials behind them from the ones resting entirely on rodent studies — and names what would change the verdict.
Peptides are credited with dozens of benefits. Some are proven in large trials, some are modest and real, and some have never been tested in a person. This is every major benefit claim, sorted by how strong the human evidence is.
Semaglutide and tirzepatide have now shown benefits in cardiovascular events, kidney disease, liver disease, heart failure and sleep apnoea — each in its own trial, in its own population. Here is what each one actually demonstrated.
Collagen peptides have more randomised human trials than any other supplement peptide. The benefits are real, small, and take 8–24 weeks to appear. Here is what each one is worth in measurable terms.
Semaglutide and tirzepatide are the best-evidenced peptides in medicine — for specific uses. We separate the approved indications with large trials from the emerging research (kidney, liver, heart failure, sleep apnoea, Alzheimer's) and the open questions about regain, muscle loss and compounded products.
BPC-157 has hundreds of positive animal studies and almost no controlled human data. We separate what the rat research shows, what the few human reports show, what the FDA has said, and what would have to happen for the evidence grade to change.
A certificate of analysis is the main reassurance offered by 'research peptide' vendors. Here is what a CoA can and cannot tell you — identity, purity, quantity, sterility, endotoxin — why '99% pure' is not what it sounds like, and what independent testing of grey-market peptides has found.
The 'CJC/ipa' stack is sold for muscle, fat loss, sleep and anti-aging. The human evidence is a handful of short hormone-level studies, two abandoned development programmes, and no outcome trials — plus a set of risks that have never been studied because the trials were never run.
Tesamorelin is the one GHRH analogue that finished phase 3 and won FDA approval — for excess abdominal fat in HIV-associated lipodystrophy. We separate that established evidence from the off-label uses it is now marketed for: general visceral fat, liver fat, and cognition.
TB-500 is sold on the back of thymosin beta-4 research — a different molecule with real but early human trials in wounds and eye disease. We untangle which studies are about what, and what that means for the fragment people actually buy.
PT-141 (bremelanotide) is FDA-approved as Vyleesi for low sexual desire in premenopausal women, with modest benefits and a lot of nausea. Its use in men — the way it is mostly marketed online — was abandoned in development. Here is what the trials actually showed.
Copper peptide GHK-Cu has decades of laboratory work, small human trials for topical skin use, and a growing injectable market with no human data. We grade each claim — skin, hair, wounds, 'gene resetting' — separately.
Oral collagen peptides are the rare non-drug peptide product with multiple randomised trials. The effects on skin hydration, activity-related joint pain and (with training) lean mass are real but small, and most trials are industry-funded. Here is what the studies show and where the gaps are.
The regulatory status of a peptide is a fact about a decision, not a verdict on the evidence. This guide explains the four categories, what compounding rules changed in 2023–2025, and where every peptide we cover currently sits.
Most misleading peptide claims cite real studies. This guide shows how to tell a rat model from a human trial, a mechanism from an outcome, and a case report from evidence — with worked examples from BPC-157, growth hormone secretagogues and collagen research.
Peptides are short chains of amino acids that range from approved blockbuster drugs to unregulated 'research chemicals'. Here is what the word actually covers, how peptides differ from proteins and small-molecule drugs, and why the category tells you nothing about evidence.
