MetabolicHuman RCT
FLOW: semaglutide and kidney outcomes in type 2 diabetes
FLOW gave weekly semaglutide or placebo to 3,533 adults with type 2 diabetes and kidney disease. Major kidney events were 24% less likely on semaglutide.
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Human studies
Only what has been tested in people: meta-analyses, randomised trials and other human studies. Switch on preclinical if you want the animal work too.
MetabolicHuman RCT
STEP 8: semaglutide against liraglutide, head to head
STEP 8 put semaglutide and liraglutide side by side in one phase 3 trial. At 68 weeks average weight fell 15.8% on semaglutide and 6.4% on liraglutide.
MetabolicHuman RCT
STEP 5: what two years of semaglutide did to body weight
STEP 5 followed 304 adults for two years. Average weight fell 15.2% on semaglutide 2.4 mg against 2.6% on placebo, and the loss held steady after about week 60.
MetabolicHuman RCT
STEP 3: what semaglutide added to an intensive lifestyle programme
Everyone in STEP 3 got a low-calorie diet and 30 counselling visits. Semaglutide took average weight loss to 16.0% over 68 weeks, against 5.7% on placebo.
Basics & safetyMeta-analysis
Why a 99% pure peptide can still be the wrong molecule
A purity figure is a share, not an identity. Vials have passed 99% purity screens while containing a different compound entirely, and the report looked perfect.
Basics & safetyMeta-analysis
The supplier cannot or will not show a certificate: what to do next
No certificate is not automatically a red flag, but an unverifiable one is. Here is the short list of questions that separates the two.
Basics & safetyMeta-analysis
Third-party tested peptides: what the phrase means and how to check the claim
Every supplier selling tested peptides says so. The difference between a claim and a proof is a task number, a verification page and a lot that matches.
MetabolicHuman RCT
SURMOUNT-3: what tirzepatide added after a 12-week lifestyle programme
In 579 adults who had already lost weight on a 12-week lifestyle programme, tirzepatide took off a further 18.4% over 72 weeks. Placebo gained 2.5%.
MetabolicHuman RCT
SURMOUNT-2: how much weight tirzepatide took off in people with type 2 diabetes
In 938 adults with obesity and type 2 diabetes, tirzepatide cut weight by 12.8% to 14.7% over 72 weeks, against 3.2% on placebo.
Basics & safetyMeta-analysis
Peptide purity testing: what it costs, where to send a sample, and what a home kit cannot do
A purity test is a laboratory job with a published price and a paper trail. Here is what the process actually involves, what it costs, and where the cheap shortcuts stop.
MetabolicHuman RCT
SURMOUNT-4: what happened to weight when people stopped tirzepatide
After 36 weeks on tirzepatide, 670 adults were randomised to continue or switch to placebo. Weight went down a further 5.5% in one group and up 14.0% in the other.
MetabolicHuman RCT
STEP-HFpEF: semaglutide eased symptoms in obesity-related heart failure, and the effect held across ages
In 529 people with obesity-related heart failure with preserved ejection fraction, semaglutide improved symptom scores 7.8 points above placebo. A pooled analysis of 1,145 found no age difference.
MetabolicHuman RCT
Semaglutide for alcohol use disorder: two small trials, both with fewer drinks per drinking day
Trials of 48 and 50 adults found fewer drinks per drinking day and less craving on semaglutide, but missed other targets. Both conclude that further study is justified.
SleepHuman RCT
SURMOUNT-OSA: tirzepatide cut sleep apnoea events by 20 to 24 an hour more than placebo
In two 52-week trials of adults with obesity and moderate-to-severe sleep apnoea, tirzepatide cut breathing interruptions far more than placebo. Eli Lilly funded both.
MetabolicHuman RCT
SURMOUNT-5: tirzepatide beat semaglutide by 6.5 points of body weight in a 72-week head-to-head
In 751 adults with obesity, tirzepatide cut weight by 20.2% against 13.7% on semaglutide. The trial was open-label and paid for by the maker of tirzepatide.
Basics & safetyMeta-analysis
How peptide purity is tested, and what a certificate of analysis can't tell you
A purity figure comes from one method on one batch. Here is what each lab test measures, what it misses, and how to check a lot yourself.
Basics & safetyMeta-analysis
Peptide endotoxin and sterility testing: what each test measures and why purity doesn't cover them
Endotoxin and sterility are two separate tests, and neither is implied by a purity figure. Here is what each measures, how results are reported, and what testing has found.
Basics & safetyMeta-analysis
Are peptides legal in the UK? What medicines law actually says
No UK law bans peptides as a class. What matters is whether a product is a medicine, decided case by case. Here are the law and the public record.
Basics & safetyMeta-analysis
Janoshik testing explained: what the lab does, how to verify a report, and what one test can't tell you
Janoshik reports are widely quoted and easy to check, but verification proves a document is unaltered. It does not prove the vial in front of you is what was tested.
RecoveryMeta-analysis
BPC-157 vs TB-500: what the human evidence actually is, side by side
BPC-157 has about 30 people in small uncontrolled reports. TB-500 has none yet, though full-length thymosin beta-4 has randomised trials, mostly in eyes. Neither has a controlled injury trial.
Basics & safetyHuman study
Who should not use peptides: the screening list
Active cancer, pregnancy and a known allergy rule peptides out. Several other conditions need a specialist first. Here is the list, and where each item comes from.
Basics & safetyMeta-analysis
Research use only: what the label means in the UK and US
“Research use only” is a seller’s statement, not a legal category. In both countries regulators look at how a product is sold and used, and a disclaimer doesn’t settle that.
RecoveryHuman study
BPC-157: what thousands of people report, and why that matters
Three small trials. Ten years of collected human experience, 16,000 cases. The second is the largest body of evidence on this peptide, and the one almost nobody reads.
MetabolicHuman RCT
Retatrutide: what the trials show so far, and what is still a press release
Peer-reviewed trials show 24% weight loss at 48 weeks and large falls in liver fat; the headline 28% phase 3 figure is still company-reported.
LongevityHuman RCT
Nicotinamide riboside raised NAD+ by about 60% in older adults. Nothing else clearly changed
In a six-week crossover trial of 24 healthy people aged 55 to 79, NR lifted NAD+ in blood cells and was well tolerated. Blood pressure hints were exploratory.
HormonesHuman study
Follistatin-344: the human trials used gene therapy, not an injected peptide
Every human study of follistatin-344 delivered the gene by viral vector into muscle, in a handful of patients. The protein sold in vials has no human data behind it.
SkinHuman RCT
Melanotan I and II: one became a licensed drug, the other a mole-changing tanning jab
Melanotan I, as afamelanotide, is approved for a rare light-sensitivity disease. Melanotan II was never approved, and case reports link it to changing moles and melanoma.
Basics & safetyMeta-analysis
Why most peptide evidence is in animals, and how to read it
Only about 5% of treatments tested in animals end up approved for people. Here is why rodent results mislead, and a quick way to read any peptide abstract.
Basics & safetyMeta-analysis
How to read a peptide certificate of analysis
A certificate of analysis answers four separate questions: what is in the vial, how much, how clean, and how safe to inject. Most only answer one or two.
RecoveryHuman study
What the first human BPC-157 safety study actually found
Two adults got intravenous BPC-157 on two consecutive days and had no side effects or blood-test changes. That’s all a two-person pilot can tell you.
SkinHuman RCT
OS-01: what the company-run skin trials show, and what they don't
Three small 12-week studies of the topical peptide OS-01 report better skin barrier and hydration. All were funded and authored by the company that owns it.
HormonesHuman RCT
PT-141 (bremelanotide): what the RECONNECT trials found, and what they didn’t
Bremelanotide is FDA-approved for low sexual desire in premenopausal women. In phase 3 it raised desire scores modestly, didn’t increase satisfying sexual events, and caused nausea in 40%.
Basics & safetyMeta-analysis
The FDA’s July 2026 peptide vote, explained
An FDA advisory committee backed six of seven peptides for US pharmacy compounding, against its own scientists’ advice. The vote is not binding, and nothing is legal to compound yet.
RecoveryHuman RCT
TB-500 and thymosin beta-4: a real mechanism, real eye-drop trials, and a fragment waiting on its first results
Thymosin beta-4 has been through randomised human trials, mostly as eye drops, with a clear win in neurotrophic keratopathy and flat results in the two large dry-eye studies. TB-500 is the seven-amino-acid fragment built on the actin-binding motif that started this work, and its first human trial began recruiting in February 2026.
RecoveryHuman RCT
Thymosin beta-4 eye drops for dry eye: the 72-person trial missed its main goals
Neither primary outcome improved in the larger of two published phase 2 trials. Some secondary measures did, and the drops looked safe for 28 days.
HormonesHuman RCT
Kisspeptin: what the IVF and brain studies in people actually found
Kisspeptin is one of the better-studied peptides in humans, mostly by one London group. It can trigger egg maturation in IVF, but it is still experimental and unapproved.
HormonesHuman RCT
Oxytocin: a proven labour drug, and a nasal spray that hasn’t lived up to the hype
Injected oxytocin reliably prevents bleeding after birth. The intranasal ‘trust hormone’ findings have failed to replicate, and the largest autism trial found no benefit.
MetabolicHuman RCT
Tesamorelin in HIV: the trial that showed it trims deep belly fat, and what it cost
Six months of daily tesamorelin cut visceral fat by 15.2% while placebo users gained 5.0%. Nearly half of users developed antibodies to the drug.
HormonesHuman study
Sermorelin and gonadorelin: the older hormone-releasing peptides
Both were once FDA-approved medicines, and both are now discontinued in the US. Their real track records are narrower, and more medical, than their current reputations.
LongevityHuman RCT
Glutathione: oral, IV and topical, and what each has been shown to do
Daily oral glutathione can raise body stores modestly. Skin-lightening effects are small, short-lived and based on a few trials, while IV glutathione has little evidence and a live contamination problem.
SkinHuman RCT
GHK-Cu: what the skin studies show, and why injections are a different question
A copper peptide with decades of lab work and a few small human trials on skin and ulcers. Nobody has published a trial of injecting it.
MetabolicHuman study
AOD-9604: safe in trials, but the weight loss never showed up
Rodent studies were promising and six human trials found it well tolerated, but the largest trial failed on weight loss and development for obesity stopped in 2007.
CognitiveMeta-analysis
Cerebrolysin: what the stroke and dementia trials show once you add them up
Manufacturer-backed trials and pooled analyses report benefits; independent Cochrane reviews find no effect on stroke deaths and only very low-certainty gains in dementia.
MetabolicHuman RCT
Retatrutide’s phase 2 trial: 24% weight loss at 48 weeks, in 338 people
The top dose took off 24.2% of body weight against 2.1% on placebo. It’s a striking number from a mid-sized, US-only trial with a generous way of counting.
HormonesHuman RCT
Tesamorelin: the one GHRH drug with phase 3 evidence, and what it does and doesn’t show
In two phase 3 trials of 806 people with HIV, tesamorelin cut deep belly fat by about 15% more than placebo. The fat came back when it stopped, and nobody has run the trials people now cite it for.
LongevityHuman RCT
SS-31 (elamipretide): what a decade of human trials found
Elamipretide is now an FDA-approved drug for one ultra-rare disease, on the strength of 12 patients. Its large trials in commoner conditions mostly missed their main goals.
ImmuneHuman RCT
LL-37: the body’s own antimicrobial peptide, and why the wound trials disappointed
LL-37 is central to innate immunity, but as a drug the evidence is thin: one small leg-ulcer trial looked good, and the larger follow-up failed.
MetabolicHuman RCT
Cagrilintide and CagriSema: what the amylin trials found
Alone, cagrilintide cut weight by about 11% in 26 weeks; paired with semaglutide it reached 20% at 68 weeks, but lost a head-to-head against tirzepatide.
ImmuneHuman RCT
ARA-290 (cibinetide): what the small nerve-repair trials found
Three small phase 2 trials suggest it can regrow damaged small nerve fibres; the pain results are weaker, and there has never been a phase 3 trial.
MetabolicHuman RCT
SELECT: semaglutide cut major heart events by 20% in people who already had heart disease
In 17,604 adults with obesity and existing cardiovascular disease but no diabetes, semaglutide lowered major cardiac events from 8.0% to 6.5% over about three years.
SleepHuman RCT
DSIP: why the ‘sleep peptide’ never became a sleep drug
Swiss trials in the 1980s reported better sleep with DSIP; the two independent placebo-controlled trials found little of clinical value. Nobody has found its gene or receptor.
Basics & safetyHuman RCT
Injected, oral or nasal: does the route matter for peptides?
Yes, a lot. Most peptides are destroyed or blocked in the gut, which is why nearly all peptide drugs are injected. Oral semaglutide is the exception, and it needed special engineering.
LongevityHuman RCT
NAD+, NMN and NR: what the human trials actually show
Oral NR and NMN reliably raise NAD+ in blood, and one 10-week trial moved muscle insulin sensitivity by 25%. Beyond that the health effects are modest and mixed, and the injected form is the least studied route of all.
HormonesHuman study
Ipamorelin: a selective growth hormone pulse, and the blend question still open
Ipamorelin releases growth hormone in a short, selective pulse. Its human record is a 1999 dosing study and a 2014 surgical trial that missed its primary endpoint; the CJC-1295 combination is where the human evidence stops.
MetabolicHuman RCT
SURMOUNT-1: how much weight tirzepatide took off in 72 weeks
At the top dose, people lost 20.9% of their body weight against 3.1% on placebo. Here is who was in the trial, what it cost them in side effects, and what it can’t tell you.
MetabolicHuman RCT
Tirzepatide: what SURMOUNT and SURPASS found
Around 20% average weight loss at 72 weeks, a clear head-to-head win over semaglutide, and heart-outcome data that holds up against an older GLP-1 drug.
CognitiveHuman study
Semax: what the stroke studies found, and which ACTH fragment it really is
Semax is ACTH(4-7) with a Pro-Gly-Pro tail, which is why papers also call it an ACTH(4-10) analogue. Its human evidence is a few small, unblinded Russian stroke studies.
ImmuneHuman RCT
Thymosin alpha-1: what decades of human trials actually show
A licensed drug in some countries with thousands of trial patients behind it, but its biggest modern trials in sepsis and hepatitis C found no benefit.
ImmuneHuman RCT
Larazotide: what happened to the coeliac drug that reached Phase 3
Five controlled coeliac trials, one small positive signal at the lowest dose, and a Phase 3 stopped in 2022 because it wasn't going to work.
LongevityHuman study
Epitalon: what the human evidence actually is, and who produced it
The human data on epitalon come from one research network, and they tested a pineal extract rather than the synthetic peptide itself. Independent work so far is limited to cells.
HormonesHuman study
CJC-1295: what two small 2006 studies showed, and why nothing followed
One version of CJC-1295 raised growth hormone for about a week in healthy adults. The other, sold as “no DAC”, has never been tested in people at all.
MetabolicHuman RCT
STEP 1: what the semaglutide 2.4 mg obesity trial actually found
Weekly semaglutide cut body weight by 14.9% over 68 weeks against 2.4% on placebo. Most of that came back within a year of stopping.
MetabolicHuman RCT
Semaglutide: what the big trials actually showed
About 15% weight loss at 68 weeks, fewer heart attacks and slower kidney decline in large trials, with stomach side effects, gallbladder risk and weight regain on stopping.
CognitiveHuman study
Selank: what the anxiety trials actually tested, and where
Four small Russian studies, one network, eighteen years, and the same result each time: anxiety eased about as much as on a benzodiazepine, without the sedation.
Basics & safetyMeta-analysis
How to read a peptide study in five minutes
Seven questions that sort a real finding from a weak one: who was studied, how many, compared with what, measured how, for how long, and who paid.