Independent peptide research
What each compound is, what human research actually shows, and what is still only a claim — written plainly, graded honestly, updated as the studies land. Nothing to buy, nobody listed, nobody paying.
Pick one — the answer changes what we show you first.
What LYO does
One row per claimed effect, per compound. A grade from A to D based only on human evidence, an effect size, and the studies behind it.
See the evidence matrix →Six short lessons with a check at the end of each. By the third you can look at any peptide claim and know what it is worth.
Start the lessons →New trials and reviews, read in full and reduced to what changed. When a study moves a grade, the change is logged and dated.
This week's feed →Learn
Most bad decisions in this space come from not being able to read a study. A few minutes each, with a check at the end of every one. Progress is saved on this device.
Every outcome on this site carries a grade from A to D. The grade is not about whether a compound “works” — it is about how much human evidence exists and how consistent it is. A compound can be genuinely promising and still be a D, because promising is not the same as proven.
Grades only count studies in humans. A hundred rodent papers do not move a grade above D. That rule alone explains most of what you'll see here.
A compound has 40 rodent studies showing faster tendon healing and no human trials. What grade does the tendon-healing outcome get?
Reference
One page per compound. A direct answer in the first paragraph, an evidence matrix, the regulatory picture, and every claim traced to a study you can open.
Synthetic pentadecapeptide from a gastric protein. Striking animal results; no controlled human trials.
GLP-1 receptor agonist. Among the most-studied molecules of the decade; approved for diabetes and obesity.
Triple GIP / GLP-1 / glucagon agonist. Large phase 2 effect on weight; phase 3 still reporting.
Dual GIP / GLP-1 agonist. Approved; head-to-head data against semaglutide now published.
GHRH analogue. Approved for one narrow indication; evidence outside it is thin.
Selective GH secretagogue. A handful of small human studies before development stopped.
Copper-binding tripeptide. Reasonable human data for topical skin use; injectable use is unstudied.
Synthetic tetrapeptide. Older Russian studies of limited quality; nothing replicated elsewhere.
Evidence matrix
The table every compound page is built around. One row per claimed effect; a grade, a size, and how many human studies stand behind it.
BPC-157 in one line: The most-discussed healing peptide on the internet has never been tested in a controlled human trial. Every outcome below is graded on animal data, which is why every grade is a D — not because the results are bad, but because they are not yet about people.
| Outcome | Grade | Effect size | Human studies | Where the evidence comes from |
|---|---|---|---|---|
| Tendon & ligament healing | DNo human evidence | Not measurable | 0 controlled | Rodent models of Achilles and MCL injury. Consistent in animals; no human trial has been run.12 |
| Gut mucosal healing | DNo human evidence | Not measurable | 0 controlled | Rat ulcer and colitis models. The original research programme; still preclinical.1 |
| Pain reduction | DNo human evidence | Not measurable | 1 case series (n=12) | A retrospective case report of 12 knee-pain patients given intra-articular injections; no control group. The only human study a 2025 systematic review could find.3 |
| Safety in humansadverse | DNo human evidence | Not measurable | 1 open-label pilot (n=2) | Two healthy adults given intravenous doses in an uncontrolled 2025 pilot showed no biomarker changes. That is the entire human safety literature.345 |
Several well-run randomised trials in people, pointing the same way. You can plan around this. It still says nothing about whether the effect is worth the side effects for you.
e.g. semaglutide → body weight
Research feed
New studies and reviews, reduced to what changed and whether a grade moved.
Lilly's largest phase 3 (2,339 adults) reports −28.3% on the top dose at 80 weeks and −30.3% at 104 weeks in a heavier subgroup. Discontinuation for side effects was 11.3% vs 4.9% on placebo. None of it is peer-reviewed yet, so the grade stays B — the effect size is not in question; the scrutiny is.
445 adults with obesity and knee osteoarthritis lost 28.7% at 68 weeks against 2.1% on placebo, with WOMAC pain falling by up to 76%. The cost: nausea in ~40%, vomiting in ~20%, and 12–18% stopping for side effects. Topline only.
Vasireddi and colleagues screened 544 articles from three decades. Thirty-five of the 36 included studies were preclinical; the single clinical study was a 12-patient retrospective case report. No clinical safety data. It is the citation for the next time someone says the research is clear.
SURMOUNT-5 put the two most-prescribed peptides in the same trial. Tirzepatide produced more weight loss with a similar side-effect profile — the comparison people ask about, answered directly rather than across studies.
Regulation
The most-searched question in the category and the least honestly answered. Plain-language status, kept current.
Most research peptides have no marketing authorisation. Selling them for human use is a criminal offence for the seller. Approved compounds are prescription-only.
Sold as research chemicals, not for human consumption. FDA has restricted several compounds from pharmacy compounding.
Unlicensed medicines under the Human Medicines Regulations. The MHRA is prosecuting sellers, particularly of weight-loss injectables.
Läkemedelsverket treats these as medicines. Approved compounds are prescription-only; the rest are not authorised for sale.
Glossary
Independence
LYO exists to answer one question honestly: what does the evidence actually say? That only works if there is no reason to shade the answer — so we have removed every reason.