Peptide Library

Cerebrolysin is a mix of peptides and amino acids made from pig brain tissue. It is given by injection in parts of Europe and Asia. Real human trials exist, and some are positive. But the Cochrane review of acute ischaemic stroke found no benefit on death. It also found more non fatal serious adverse events. Results in dementia and head injury look better, though reviewers rated that evidence weak. It is not approved in the United States.

Dihexa is a small synthetic molecule built from a fragment of angiotensin IV, a natural brain peptide. It is studied for memory. The honest answer is that there is no human evidence. Every result below comes from rats, mice, zebrafish or cells in a dish. FDA states it has found no human exposure data for dihexa by any route. Nobody knows how it behaves in a person, including whether it is safe.

Selank is a Russian anti-anxiety peptide, and the honest answer is that the human evidence is real but thin. Three small Russian trials, the largest around 70 people, report that it eases anxiety about as well as a benzodiazepine. It brought less of the sedation and memory dulling those drugs cause. Almost everything else comes from rats and cells. No dedicated human safety study has been published. It is not an approved medicine in the United States.

Semax is a lab made peptide based on a fragment of ACTH, a human hormone. Russia registered it as a drug for stroke and poor brain blood flow. The human evidence is real but thin. Most trials are Russian, small, and not blinded to modern standards. Western regulators have never reviewed it. The FDA says it does not have enough safety information to know whether Semax would harm people. Treat it as promising but unproven.

AOD-9604 is a small fragment of human growth hormone. It was developed as an obesity drug and never approved. Australian researchers took it into mid stage human trials in the early 2000s. No results from those trials appear in the published medical literature, and no regulator approved it. The evidence that does exist is animal work. Obese mice and rats gained less weight and burned more fat. In people, the fat loss claim is unproven.

CJC-1295 is a lab made copy of growth hormone releasing hormone. The version studied in people, CJC-1295 with DAC, sticks to blood albumin and keeps working for days. In healthy adults it raised growth hormone and IGF-1 for over a week. That is the whole human record: two small trials in the mid 2000s. Nobody has tested whether it builds muscle, burns fat or slows ageing in people. The version without DAC has no human trials at all.

Hexarelin is a synthetic six amino acid peptide that makes the pituitary release growth hormone. Real human trials ran in the 1990s, including studies of heart function. That makes the evidence stronger than for most research peptides. Those same trials found a clear problem: the growth hormone response fades when you keep using it. Hexarelin is not an approved medicine anywhere. No trial has followed anyone taking it beyond about ten months.

Ipamorelin is a lab made peptide that tells your pituitary gland to release a pulse of growth hormone. It does that in people: a study in healthy men measured a clear growth hormone burst. But the one proper efficacy trial, in bowel surgery patients, failed. Ipamorelin did no better than placebo. Every claim about muscle, fat loss, bone or recovery rests on rats, mice, pigs or cells. It is not an approved medicine.

Sermorelin is a synthetic copy of the first 29 amino acids of growth hormone releasing hormone (GHRH). It tells your pituitary gland to release its own growth hormone. Real clinical evidence exists, but nearly all of it is in children with growth hormone deficiency. Two small trials in older adults found modest changes. No trial has tested it for anti ageing, fat loss or muscle gain in healthy adults. It was once an approved US medicine. It is not one today.

Tesamorelin is an approved prescription medicine, not a research chemical. The FDA cleared it in 2010 under the brand Egrifta. Its approval covers one narrow job: cutting excess belly fat in adults with HIV. Those patients have lipodystrophy (a condition that changes where the body stores fat). The label states it is not approved for weight loss. Inside that group the human evidence is strong, with large placebo controlled trials. Outside HIV, the evidence is much thinner.

HCG is a prescription hormone, not a supplement. The FDA approves it for some cases of female infertility and for hormone treatment in men. In men whose brain signal to the testicles has failed, trials show it raises testosterone, and with FSH it can start sperm production. It does nothing for fat loss. Placebo controlled trials found no extra weight loss, and the FDA says the over the counter HCG diet drops are illegally marketed.

Kisspeptin-10 is a ten amino acid piece of a natural reproductive hormone. In men, short infusions raise LH and testosterone. In women the response depends on the menstrual cycle. The trials on sexual desire and mood used the longer form, kisspeptin-54, not kisspeptin-10. All of this human work used supervised infusions in a hospital. Nobody has tested repeated self-injection. The FDA lists kisspeptin-10 as a substance that may present significant safety risks.

KPV is a peptide just three amino acids long. It is the tail end of a natural hormone called alpha-MSH, one of the signals your body uses to calm inflammation. In animals it settles inflammation in the gut. It also survives being swallowed, because the gut has a transporter that pulls it straight into the cells lining the intestine. Every published study is in cells, mice or rats. No human trial of KPV exists.

Thymosin alpha-1 has more real human evidence behind it than almost any other research peptide. It is an approved prescription medicine in more than 30 countries outside the United States, mostly for chronic hepatitis B. Trials in hepatitis B, sepsis and COVID-19 have reported benefits. But the largest and best designed sepsis trial, published in 2025, found no effect on deaths. The picture is genuinely mixed. Nobody has tested it in healthy people looking for an immune boost.

Epitalon is a four amino acid peptide from Soviet era Russian ageing research. The honest answer: nobody has shown it extends human life. Its telomere claims rest on cell studies, several from the group that invented it. The long human trials people cite used epithalamin, a pineal gland extract, not this peptide. Epitalon itself has no published human safety record. Treat the longevity marketing as unproven, because it is.

MOTS-c is a peptide your own mitochondria make. Research groups use it to study insulin sensitivity, exercise capacity and ageing. Nearly all of that work is in mice and in cells. The one finding measured directly in people is that exercise raises your own MOTS-c. No trial has yet reported what happens when you inject it, so there is no clinically established dose and no human safety record.

Retatrutide is an experimental drug. It is not approved anywhere in the world. Eli Lilly is still testing it. Published human results come from phase 1 and 2 trials, plus one phase 3 trial published in June 2026. In those trials it cut body weight, blood sugar and liver fat in adults with obesity or type 2 diabetes. Phase 3 trials are running now. Nobody knows yet how safe it is over years. Outside its trials, Lilly lists an expanded access program that a patient's treating doctor can request.

Semaglutide is different from most compounds on this site. It is an approved prescription medicine, backed by large randomised human trials. Those trials show major weight loss, better blood sugar, fewer heart attacks and strokes, and slower kidney decline. The evidence grade here is human, not animal. It also carries real risks: gut side effects are common, gallbladder problems are less common but serious, and the weight returns once treatment stops. Only the approved products carry the evidence described here.

Tirzepatide is an approved prescription medicine, not a research chemical. The FDA cleared it as Mounjaro for type 2 diabetes and as Zepbound for weight management. Zepbound is also approved for moderate to severe obstructive sleep apnoea in adults with obesity. The evidence here is human and unusually large. The SURPASS and SURMOUNT trial programmes ran for years in thousands of people. They show big drops in weight and blood sugar. Gut side effects are common, and gallbladder problems are raised.

BPC-157 is a synthetic 15 amino acid peptide. Most of what is known about it comes from animal studies, chiefly in rats and mice. In those studies it has been reported to speed healing of tendon, ligament, gut and skin injuries. FDA says the gut and liver findings should be interpreted with caution, because no dose-response relationship was established and how BPC-157 works remains poorly understood. In people, FDA's 2026 briefing document lists five small clinical studies. Two were placebo-controlled enema studies, reported only as meeting abstracts. FDA found too little clinical safety information to describe its safety profile. It is not approved by the FDA for anything.

GHK-Cu is a copper carrying peptide used in skin creams and, increasingly, in unapproved injections. The honest answer is that the human evidence is thin. One small trial after laser resurfacing found better patient rated skin quality but no measurable difference. A larger trial in leg ulcers found no benefit over placebo. Almost everything else comes from rats, rabbits and cell cultures. FDA lists injectable GHK-Cu among substances with limited human safety data.

TB-500 is a lab made copy of a seven amino acid piece of thymosin beta-4, a natural repair protein. No clinical trial has ever tested TB-500 in people. The healing evidence comes from rats, mice, horses and cell cultures. Human trials do exist, but they used the full thymosin beta-4 protein. That is a bigger, different molecule. The FDA lists TB-500 as a bulk substance it has no human exposure data for.

DSIP is a small brain peptide named for the deep sleep waves it was thought to trigger. Human trials exist, but they are old, small, and they disagree. Some 1980s studies found better sleep in people with insomnia. Two double-blind trials found gains too small to matter. A 2009 anaesthesia trial found it cut delta waves instead of raising them. No regulator has approved it as a medicine. The evidence is weak and unsettled.