# LYO Research — full text digest
Independent, evidence-graded reference on peptides. What each compound is, what human research shows, and what is still only a claim. No products, no vendors, no sponsors.
Grades count human evidence only: A established, B probable, C weak, D no human evidence. Not medical advice. Cite as “LYO Research” with a link. Last reviewed 2026-09-02. Methodology: https://lyoresearch.com/methodology
# BPC-157 — no human evidence (grade D)
Source: https://lyoresearch.com/compounds/bpc-157 · Last reviewed 2026-09-02 · Regulatory status: Not approved

BPC-157 is a synthetic 15-amino-acid peptide derived from a protein found in human gastric juice. In rodents it consistently speeds healing of tendon, ligament, muscle and gut injury. In people it has never been tested in a controlled trial, so every human claim about it — healing, pain relief, safety — is currently unproven. It is not an approved medicine anywhere and is prohibited in sport.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Tendon & ligament healing: grade D (no human evidence), effect not measurable, human studies: 0 controlled. Rodent models of Achilles and MCL injury. Consistent in animals; no human trial has been run. [1,2]
- Gut mucosal healing: grade D (no human evidence), effect not measurable, human studies: 0 controlled. Rat ulcer and colitis models. The original research programme; still preclinical. [1]
- Pain reduction: grade D (no human evidence), effect not measurable, human studies: 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 humans: grade D (no human evidence), effect not measurable, adverse, human studies: 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. [3,4,5]

Regulatory status:
- European Union: Unapproved medicinal product. No marketing authorisation. Sale for human use is an offence for the seller.
- United States: Not approved; compounding restricted. FDA placed BPC-157 in a category that bars it from pharmacy compounding, citing safety uncertainty.
- Sport (WADA): Prohibited. Listed as a non-approved substance under the prohibited list since 2022.
- Sweden: Unapproved. Läkemedelsverket treats it as a medicine without authorisation.

Questions:
Q: Is there any human research on BPC-157?
A: No controlled trials. A 2025 systematic review screened 544 articles from 1993–2024 and found one human study — a retrospective case report of 12 patients — alongside 35 animal studies. A separate 2025 pilot gave the peptide intravenously to two healthy volunteers without a control group. Neither design can show that the peptide caused an effect.
Q: Why is the grade D if the animal results are so consistent?
A: Because LYO grades only count human evidence. Consistent animal data is exactly the reason a human trial should be run — it is not a reason to grade as though one had been.
Q: Is BPC-157 safe?
A: Unknown. No systematic safety data exists in humans. A lack of reported harm in a market with no reporting system is not evidence of safety.
Q: Is BPC-157 legal?
A: It is not an approved medicine in any major market. In the EU, selling it for human use is an offence for the seller. It is prohibited in sport by WADA. Rules for possession vary by country.

References:
[1] Sikiric P, et al. Stable gastric pentadecapeptide BPC 157: novel therapy in gastrointestinal tract. Curr Pharm Des, 2011 (review). https://pubmed.ncbi.nlm.nih.gov/?term=Sikiric+BPC+157+gastrointestinal+review+2011
[2] Chang CH, et al. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. J Appl Physiol, 2011. https://pubmed.ncbi.nlm.nih.gov/?term=Chang+BPC+157+tendon+healing+2011
[3] Vasireddi N, Hahamyan H, Salata MJ, et al. Emerging use of BPC-157 in orthopaedic sports medicine: a systematic review. HSS Journal, 2025;21(4):485–495. https://doi.org/10.1177/15563316251355551
[4] Lee E, Burgess J. Intravenous BPC-157 in healthy adults: an open-label pilot. 2025 (pilot, n = 2). https://pubmed.ncbi.nlm.nih.gov/?term=BPC+157+intravenous+pilot+healthy+adults+2025
[5] U.S. FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (BPC-157). FDA, 2023. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks

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# Semaglutide — established in humans (grade A)
Source: https://lyoresearch.com/compounds/semaglutide · Last reviewed 2026-09-01 · Regulatory status: Approved (Rx)

Semaglutide is a once-weekly GLP-1 receptor agonist approved for type 2 diabetes and, at a higher dose, for weight management. In large randomised trials it produces roughly 15% average weight loss over 68 weeks and reduces major cardiovascular events in people with existing heart disease. Gastrointestinal side effects are common and are the main reason people stop. It is a prescription medicine; products sold outside that channel are unlicensed copies.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Body weight: grade A (established in humans), effect large, human studies: 15+ RCTs. STEP programme. Roughly 15% mean loss at 68 weeks versus placebo; consistent across trials. [1]
- Blood glucose (HbA1c): grade A (established in humans), effect large, human studies: 10+ RCTs. SUSTAIN programme; the original approval basis in type 2 diabetes. [2]
- Major cardiovascular events: grade A (established in humans), effect moderate, human studies: 1 large RCT. SELECT trial, 17,604 participants: a 20% relative reduction in people with established cardiovascular disease and no diabetes. [3]
- GI side effects: grade A (established in humans), effect large, adverse, human studies: All trials. Nausea, vomiting and constipation are the most common reasons people stop. Well quantified. [1,3]
- Lean mass loss: grade B (probable, not settled), effect moderate, adverse, human studies: Sub-studies. A share of weight lost is lean tissue; magnitude and clinical importance still debated. [1,4]

Regulatory status:
- European Union: Approved, prescription-only. Authorised by the EMA. Grey-market versions are unlicensed medicines.
- United States: Approved, prescription-only. FDA-approved. Compounded versions were permitted during shortage and are now restricted.
- United Kingdom: Approved, prescription-only. MHRA has issued warnings about counterfeit pens.
- Sweden: Approved, prescription-only. Subsidy rules for weight management differ from diabetes.

Questions:
Q: How much weight do people lose on semaglutide?
A: In the STEP 1 trial, adults without diabetes lost about 15% of body weight on average over 68 weeks, compared with about 2.4% on placebo. Individual results vary widely.
Q: Does the weight come back after stopping?
A: Largely, yes. In the trial that withdrew treatment after a year, participants regained about two-thirds of the lost weight within the following year.
Q: Is semaglutide a peptide?
A: Yes — it is a 31-amino-acid peptide, a modified form of the natural hormone GLP-1.
Q: Why are there so many fake versions?
A: Demand outstripped supply for several years, and the molecule is relatively simple to synthesise. Products sold outside the prescription channel are unlicensed and, in enforcement seizures, frequently underdosed or misidentified.

References:
[1] Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med, 2021;384:989–1002. https://pubmed.ncbi.nlm.nih.gov/?term=Wilding+STEP+1+semaglutide+2021+NEJM
[2] Sorli C, et al. Efficacy and safety of once-weekly semaglutide monotherapy versus placebo in type 2 diabetes (SUSTAIN 1). Lancet Diabetes Endocrinol, 2017. https://pubmed.ncbi.nlm.nih.gov/?term=Sorli+SUSTAIN+1+semaglutide+2017
[3] Lincoff AM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes (SELECT). N Engl J Med, 2023;389:2221–2232. https://pubmed.ncbi.nlm.nih.gov/?term=Lincoff+SELECT+semaglutide+cardiovascular+2023
[4] Wilding JPH, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes Obes Metab, 2022. https://pubmed.ncbi.nlm.nih.gov/?term=Wilding+STEP+1+extension+withdrawal+semaglutide+2022

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# Retatrutide — probable, not settled (grade B)
Source: https://lyoresearch.com/compounds/retatrutide · Last reviewed 2026-09-02 · Regulatory status: Investigational

Retatrutide is an investigational once-weekly peptide that activates three receptors at once: GIP, GLP-1 and glucagon. Phase 3 topline results announced in December 2025 and May 2026 report average weight loss of about 26–29% at 68–80 weeks — the largest yet for a single drug — with high rates of nausea and more people stopping for side effects than on placebo. The full data are not yet peer-reviewed. It is not approved anywhere, and no legitimate supply exists outside clinical trials.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Body weight: grade B (probable, not settled), effect large, human studies: 1 phase 2 RCT published; 2 phase 3 RCTs topline. Phase 2: −24.2% at 48 weeks on 12 mg. Phase 3 TRIUMPH-4: −28.7% at 68 weeks vs −2.1% placebo. TRIUMPH-1 (2,339 adults): −28.3% at 80 weeks on 12 mg, −30.3% at 104 weeks in the BMI ≥35 extension. Press releases; peer review pending. [1,2,3]
- Knee osteoarthritis pain: grade B (probable, not settled), effect moderate, human studies: 1 phase 3 RCT topline. TRIUMPH-4 enrolled adults with obesity and knee osteoarthritis: WOMAC pain fell by up to 4.5 points (75.8%) vs 2.4 (40.3%) on placebo. Weight loss likely explains much of it; not yet peer-reviewed. [2]
- GI side effects: grade B (probable, not settled), effect large, adverse, human studies: Phase 2 + phase 3 topline. TRIUMPH-4: nausea 38–43% vs 11%, vomiting 20–21% vs 0%; discontinuation for adverse events 12–18% vs 4%. TRIUMPH-1: 11.3% stopped on 12 mg vs 4.9% placebo. [1,2,3]
- Dysesthesia (skin sensation changes): grade B (probable, not settled), effect small, adverse, human studies: Phase 3 topline. Reported in 9–21% of treated participants vs 0.7% on placebo in TRIUMPH-4 — an effect not prominent with older GLP-1 drugs. [2]

Regulatory status:
- European Union: Not authorised — investigational. No marketing application decided. Any product sold as retatrutide in the EU is an unlicensed medicine of unknown provenance.
- United States: Not approved — in phase 3. Available only inside clinical trials. Lilly has said it expects to file for approval after the TRIUMPH programme completes.
- United Kingdom: Not authorised. MHRA has warned about unlicensed weight-loss injectables sold online.
- Sweden: Not authorised. Not on the Läkemedelsverket register; cannot be prescribed.

Questions:
Q: How much weight do people lose on retatrutide?
A: In the phase 3 TRIUMPH-1 topline, adults on the 12 mg dose lost 28.3% of body weight on average over 80 weeks, and 30.3% at 104 weeks in a heavier subgroup. In phase 2 the figure was 24.2% at 48 weeks. These are averages from press releases; the peer-reviewed papers will give the spread.
Q: Is retatrutide better than tirzepatide?
A: Probably more weight loss, on the numbers so far — but no trial has compared them head-to-head, and cross-trial comparisons are unreliable. The side-effect burden also appears higher. Treat “better” as unsettled until a direct comparison exists.
Q: Is retatrutide available?
A: Not legally, anywhere. It is an investigational medicine available only in clinical trials. Products sold online under the name are unlicensed and, in enforcement seizures, frequently not what the label says.
Q: Why is the grade B and not A?
A: Because the phase 3 results exist only as company press releases. LYO's A grade requires peer-reviewed publication of multiple trials. The grade will be reviewed when the TRIUMPH papers appear.

References:
[1] Jastreboff AM, et al. Triple-hormone-receptor agonist retatrutide for obesity — a phase 2 trial. N Engl J Med, 2023;389:514–526. https://pubmed.ncbi.nlm.nih.gov/?term=Jastreboff+retatrutide+phase+2+obesity+2023
[2] Eli Lilly. Retatrutide delivered weight loss of up to an average of 71.2 lbs along with substantial relief from osteoarthritis pain in first successful phase 3 trial (TRIUMPH-4). Press release, 11 Dec 2025. https://investor.lilly.com/news-releases/news-release-details/lillys-triple-agonist-retatrutide-delivered-weight-loss-average
[3] Eli Lilly. Retatrutide TRIUMPH-1 topline results (NCT05929066). Press release, May 2026. https://www.ajmc.com/view/retatrutide-achieves-up-to-30-3-average-weight-loss-in-phase-3-triumph-1-trial

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# Tirzepatide — established in humans (grade A)
Source: https://lyoresearch.com/compounds/tirzepatide · Last reviewed 2026-09-02 · Regulatory status: Approved (Rx)

Tirzepatide is a once-weekly peptide that activates both GIP and GLP-1 receptors. It is approved for type 2 diabetes, weight management and obstructive sleep apnoea, and in the only direct head-to-head trial it produced more weight loss than semaglutide (20.2% vs 13.7% at 72 weeks) with a similar side-effect profile. It is a prescription medicine; versions sold outside that channel are unlicensed.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Body weight: grade A (established in humans), effect large, human studies: 10+ RCTs. SURMOUNT-1: −20.9% at 72 weeks on 15 mg vs −3.1% placebo in 2,539 adults. SURMOUNT-5 head-to-head: −20.2% vs −13.7% on semaglutide at 72 weeks. [1,2]
- Blood glucose (HbA1c): grade A (established in humans), effect large, human studies: 5 SURPASS RCTs. SURPASS-2: HbA1c reductions of 2.0–2.3 points vs 1.9 on semaglutide 1 mg in type 2 diabetes. [3]
- Obstructive sleep apnoea: grade A (established in humans), effect moderate, human studies: 2 RCTs. SURMOUNT-OSA: apnoea–hypopnoea index fell by roughly 25–30 events per hour vs 5–6 on placebo; basis of the 2024 approval. [4]
- Cardiovascular events: grade B (probable, not settled), effect small, human studies: 1 outcomes RCT (2025). SURPASS-CVOT reported tirzepatide non-inferior to dulaglutide on major adverse cardiovascular events in type 2 diabetes; superiority over an active GLP-1 comparator was not shown. [5]
- GI side effects: grade A (established in humans), effect large, adverse, human studies: All trials. Nausea, diarrhoea and vomiting, mostly during dose escalation. In SURMOUNT-5, GI-related discontinuation was 2.7% vs 5.6% on semaglutide. [1,2]

Regulatory status:
- European Union: Approved, prescription-only. Mounjaro is authorised by the EMA for type 2 diabetes and weight management.
- United States: Approved, prescription-only. Mounjaro (diabetes), Zepbound (obesity, sleep apnoea). Compounded copies were permitted during shortage and are now restricted.
- United Kingdom: Approved, prescription-only. NHS rollout for obesity began in 2025 under eligibility criteria.
- Sweden: Approved, prescription-only. Subsidy differs between diabetes and weight-management use.

Questions:
Q: Is tirzepatide better than semaglutide for weight loss?
A: On the only head-to-head trial, yes: 20.2% versus 13.7% average loss at 72 weeks in 751 adults, with fewer people stopping for gut side effects on tirzepatide. Individual response varies a great deal.
Q: Is tirzepatide a peptide?
A: Yes — a 39-amino-acid synthetic peptide based on the GIP hormone, modified to also activate GLP-1 receptors and to last about five days.
Q: What are the main side effects?
A: Nausea, diarrhoea, vomiting and constipation, mostly while the dose is being increased. Rarer but serious: pancreatitis and gallbladder problems. It carries the same thyroid C-cell tumour warning as other GLP-1 drugs, based on rodent findings.
Q: Does the weight come back after stopping?
A: Largely. In SURMOUNT-4, people switched to placebo after 36 weeks regained about half of what they had lost within a year, while those who continued kept losing.

References:
[1] Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med, 2022;387:205–216. https://pubmed.ncbi.nlm.nih.gov/?term=Jastreboff+SURMOUNT-1+tirzepatide+2022
[2] Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as compared with semaglutide for the treatment of obesity (SURMOUNT-5). N Engl J Med, 2025;393(1):26–36. https://pubmed.ncbi.nlm.nih.gov/40353578/
[3] Frías JP, et al. Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes (SURPASS-2). N Engl J Med, 2021;385:503–515. https://pubmed.ncbi.nlm.nih.gov/?term=Frias+SURPASS-2+tirzepatide+semaglutide+2021
[4] Malhotra A, et al. Tirzepatide for the treatment of obstructive sleep apnea and obesity (SURMOUNT-OSA). N Engl J Med, 2024;391:1193–1205. https://pubmed.ncbi.nlm.nih.gov/?term=Malhotra+SURMOUNT-OSA+tirzepatide+2024
[5] Eli Lilly. SURPASS-CVOT topline: tirzepatide vs dulaglutide on cardiovascular outcomes in type 2 diabetes. Press release, 2025; full publication pending at time of review. https://pubmed.ncbi.nlm.nih.gov/?term=SURPASS-CVOT+tirzepatide+dulaglutide

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# Tesamorelin — probable, not settled (grade B)
Source: https://lyoresearch.com/compounds/tesamorelin · Last reviewed 2026-09-02 · Regulatory status: Approved (Rx, US)

Tesamorelin is a synthetic analogue of growth-hormone-releasing hormone, approved in the United States to reduce excess abdominal fat in people with HIV-associated lipodystrophy. In that population it cuts visceral fat by about 15% over six months, and the fat returns when treatment stops. Its use for general fat loss, muscle or anti-ageing rests on extrapolation from that specific group; there are no trials in healthy adults. It is not authorised in the EU.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Visceral fat (HIV lipodystrophy): grade A (established in humans), effect moderate, human studies: 2 phase 3 RCTs (n=816). Pooled phase 3: visceral adipose tissue −15.2% at 26 weeks vs +5% on placebo; effect lost within 26 weeks of stopping. [1]
- Liver fat (HIV with NAFLD): grade B (probable, not settled), effect moderate, human studies: 1 RCT (n=61). Hepatic fat fraction fell by about a third over 12 months vs placebo; a specific population, one trial. [2]
- Cognition in older adults: grade C (weak human evidence), effect small, human studies: 1 RCT (n=152). 20 weeks of tesamorelin improved some executive-function measures in healthy older adults and those with mild cognitive impairment. Single trial, never replicated or developed further. [3]
- Fat loss in healthy adults: grade D (no human evidence), effect not measurable, human studies: None. Not studied. The approved population is not a proxy for the general public.
- IGF-1 elevation and glucose effects: grade A (established in humans), effect small, adverse, human studies: Phase 3 programme. Raises IGF-1 as intended; small rises in blood glucose and injection-site reactions are documented. Long-term cancer risk at elevated IGF-1 is the reason for the narrow label. [1]

Regulatory status:
- United States: Approved, prescription-only (narrow indication). Egrifta, for excess abdominal fat in HIV-associated lipodystrophy only.
- European Union: Not authorised. The EMA application was withdrawn; no EU marketing authorisation exists.
- United Kingdom: Not authorised. Not licensed by the MHRA.
- Sport (WADA): Prohibited. Growth-hormone-releasing factors are banned at all times.

Questions:
Q: Does tesamorelin burn belly fat?
A: In people with HIV-associated lipodystrophy, yes — about 15% less visceral fat after six months in two phase 3 trials. In anyone else it has not been tested, and the fat returns when treatment stops.
Q: Is tesamorelin the same as growth hormone?
A: No. It prompts the body to release its own growth hormone rather than supplying it. The downstream effects overlap, including higher IGF-1.
Q: Is tesamorelin legal?
A: It is a prescription medicine in the United States for one indication. It is not authorised in the EU or UK, and it is banned in sport.

References:
[1] Falutz J, et al. Effects of tesamorelin, a growth hormone-releasing factor, in HIV-infected patients with abdominal fat accumulation: pooled analysis of two phase 3 trials. J Acquir Immune Defic Syndr, 2010;53:311–322. https://pubmed.ncbi.nlm.nih.gov/?term=Falutz+tesamorelin+pooled+phase+3+2010
[2] Stanley TL, et al. Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, placebo-controlled trial. Lancet HIV, 2019. https://pubmed.ncbi.nlm.nih.gov/?term=Stanley+tesamorelin+NAFLD+HIV+Lancet+HIV+2019
[3] Baker LD, et al. Effects of growth hormone-releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults. Arch Neurol, 2012;69:1420–1429. https://pubmed.ncbi.nlm.nih.gov/?term=Baker+tesamorelin+cognitive+function+older+adults+2012

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# Ipamorelin — weak human evidence (grade C)
Source: https://lyoresearch.com/compounds/ipamorelin · Last reviewed 2026-09-02 · Regulatory status: Not approved

Ipamorelin is a synthetic five-amino-acid peptide that stimulates growth-hormone release with little effect on cortisol or prolactin. Small early studies confirmed the hormone release; the only randomised trial — 117 bowel-surgery patients, testing it for post-operative gut recovery — found no benefit, and development stopped. It is not an approved medicine anywhere, and the popular claims about muscle, fat loss and sleep have never been tested in a trial.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Growth hormone release: grade C (weak human evidence), effect moderate, human studies: Small early-phase studies. Acute, dose-dependent GH rises demonstrated in healthy volunteers in Novo Nordisk's early programme; more selective than GHRP-6, with little cortisol or prolactin rise. [1,2]
- Post-operative ileus (gut recovery): grade C (weak human evidence), effect not measurable, human studies: 1 RCT (n=117). Median time to tolerate a solid meal 25.3 h vs 32.6 h on placebo — not statistically significant (p=0.15). No difference on secondary endpoints. Phase 3 was not pursued. [3]
- Body composition: grade D (no human evidence), effect not measurable, human studies: None controlled. No trial has measured muscle or fat change in people.
- Sleep or recovery: grade D (no human evidence), effect not measurable, human studies: None. Unstudied in humans.
- Safety in humans: grade C (weak human evidence), effect not measurable, adverse, human studies: 1 RCT + early-phase. Well tolerated over seven days of IV dosing in the ileus trial. No long-term human safety data at the doses and durations used on the grey market. [3]

Regulatory status:
- European Union: Unapproved medicinal product. No marketing authorisation. Sale for human use is an offence for the seller.
- United States: Not approved; compounding restricted. FDA has placed ipamorelin among substances that may present significant safety risks in compounding.
- Sport (WADA): Prohibited. Growth-hormone secretagogues are banned at all times.
- Sweden: Unapproved. Treated as a medicine without authorisation.

Questions:
Q: Does ipamorelin build muscle?
A: Nobody knows. It releases growth hormone in the short term, but no trial has measured muscle or fat change in people taking it. The claim is an inference from the hormone, not a result.
Q: Is ipamorelin safe?
A: It was well tolerated for a week of intravenous dosing in one trial of surgical patients. There is no human data on months of injections, which is how it is used outside medicine.
Q: Why was ipamorelin never approved?
A: Its one proper randomised trial, for post-operative gut recovery, did not meet its endpoint, and the developer stopped. No company has tested it for any other indication.

References:
[1] Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol, 1998;139:552–561. https://pubmed.ncbi.nlm.nih.gov/?term=Raun+ipamorelin+selective+growth+hormone+secretagogue+1998
[2] Gobburu JV, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res, 1999;16:1412–1416. https://pubmed.ncbi.nlm.nih.gov/?term=Gobburu+ipamorelin+pharmacokinetic+human+volunteers+1999
[3] Beck DE, Sweeney WB, McCarter MD, et al. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis, 2014;29:1527–1534. https://link.springer.com/article/10.1007/s00384-014-2030-8

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# GHK-Cu — weak human evidence (grade C)
Source: https://lyoresearch.com/compounds/ghk-cu · Last reviewed 2026-09-02 · Regulatory status: Cosmetic ingredient

GHK-Cu is a naturally occurring three-amino-acid peptide that binds copper, found in plasma, saliva and urine, with levels that fall with age. Applied to skin in creams it has modest evidence from small trials for improving fine lines and skin firmness, which is why it is a common cosmetic ingredient. Injected use — increasingly promoted online — has no human evidence of any kind.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Skin appearance (topical): grade C (weak human evidence), effect small, human studies: 3–4 small trials. Twelve-week facial studies in the late 1990s and early 2000s reported improved skin laxity, clarity and fine lines versus vehicle or comparators. Small, short, largely industry-run. [1,2]
- Wound healing (topical): grade C (weak human evidence), effect small, human studies: Small trials, mixed. A GHK-Cu gel was tested on diabetic foot ulcers in the 1990s with mixed results; the product was not carried forward. [3]
- Hair growth: grade D (no human evidence), effect not measurable, human studies: None controlled. Claims rest on cell and animal work and on analogy with minoxidil; no human trial.
- Any outcome (injected): grade D (no human evidence), effect not measurable, human studies: None. Unstudied in humans. Injecting a copper complex without data on distribution or dose is not a safety-neutral act.

Regulatory status:
- European Union: Permitted as a cosmetic ingredient. Listed in the EU cosmetic ingredient inventory. Injectable products are unlicensed medicines.
- United States: Cosmetic ingredient; injectable unapproved. Legal in topical products. Not approved as a drug; injectable versions are sold as research chemicals.
- United Kingdom: Cosmetic ingredient. As EU. Injectable use falls under unlicensed medicines rules.
- Sport (WADA): Not listed. Not a prohibited substance.

Questions:
Q: Does GHK-Cu work for wrinkles?
A: Modestly, in small twelve-week studies of topical products — improvements in fine lines, firmness and skin clarity versus vehicle. The trials are small and mostly industry-funded, so the honest answer is “probably a little.”
Q: Is injecting GHK-Cu safe?
A: Unknown. There are no human studies of injected GHK-Cu. Topical safety data does not transfer to injection.
Q: Does GHK-Cu regrow hair?
A: No human trial has tested it. The claim comes from cell and animal studies and from its structural similarity to how minoxidil is thought to act.

References:
[1] Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci, 2018;19:1987 (review). https://pubmed.ncbi.nlm.nih.gov/?term=Pickart+Margolina+GHK-Cu+2018+review
[2] Leyden JJ, et al. Skin care benefits of copper peptide containing facial cream. American Academy of Dermatology meeting, 2002 (abstract). https://pubmed.ncbi.nlm.nih.gov/?term=copper+peptide+facial+cream+skin+laxity+12+week
[3] Mulder GD, et al. Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-L-histidyl-L-lysine copper. Wound Repair Regen, 1994;2:259–269. https://pubmed.ncbi.nlm.nih.gov/?term=Mulder+glycyl-histidyl-lysine+copper+diabetic+ulcers+1994

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# Epitalon — no human evidence (grade D)
Source: https://lyoresearch.com/compounds/epitalon · Last reviewed 2026-09-02 · Regulatory status: Not approved

Epitalon is a synthetic four-amino-acid peptide (Ala-Glu-Asp-Gly) developed in St Petersburg in the 1980s and promoted for longevity on the basis of telomerase activation in cell culture and lifespan effects in mice. The human evidence comes from one research group, is uncontrolled, and much of it used Epithalamin — a pineal-gland extract — rather than the synthetic peptide sold under the name. It is not approved anywhere.

Evidence by outcome (grades count human evidence only; A established, B probable, C weak, D none):
- Lifespan / mortality: grade D (no human evidence), effect not measurable, human studies: Uncontrolled, single group. A 12–15-year observational follow-up of elderly patients from one institute reported lower mortality with Epithalamin (the extract) plus thymus extract. No randomisation, no blinding, and not the synthetic peptide. [1]
- Telomerase activation: grade D (no human evidence), effect not measurable, human studies: Cell culture only. Telomerase activity and telomere lengthening reported in cultured human fibroblasts. Never measured in a living person. [2]
- Melatonin / sleep: grade D (no human evidence), effect not measurable, human studies: Small uncontrolled. Small studies from the same group report restored night-time melatonin in elderly subjects; uncontrolled and unreplicated. [3]
- Safety in humans: grade D (no human evidence), effect not measurable, adverse, human studies: None systematic. No adverse-event data collected to modern standards. Unknown is not the same as safe.

Regulatory status:
- European Union: Unapproved medicinal product. No marketing authorisation anywhere in the EU.
- United States: Not approved. Sold as a research chemical; not approved as a drug or supplement ingredient.
- Russia: Extract registered; peptide status unclear. Epithalamin (the extract) has a Russian registration; the synthetic peptide's status is not equivalent.
- Sweden: Unapproved. Treated as a medicine without authorisation.

Questions:
Q: Does epitalon extend lifespan?
A: In mice, some studies from one group report modest lifespan effects. In humans there is no controlled evidence. The often-cited 12–15-year follow-up used Epithalamin, a pineal extract, not the synthetic peptide, and had no control group.
Q: Does epitalon lengthen telomeres?
A: In cultured cells, one group has reported telomerase activation. It has never been measured in people taking the peptide.
Q: Is epitalon safe?
A: Unknown. No systematic safety data exist. If it did activate telomerase in vivo, that would be a reason for caution, not reassurance.

References:
[1] Khavinson VKh, Morozov VG. Peptides of pineal gland and thymus prolong human life. Neuro Endocrinol Lett, 2003;24:233–240. https://pubmed.ncbi.nlm.nih.gov/?term=Khavinson+Morozov+peptides+pineal+thymus+prolong+human+life+2003
[2] Khavinson VKh, et al. Peptide promotes overcoming of the division limit in human somatic cell. Bull Exp Biol Med, 2003;135:503–506. https://pubmed.ncbi.nlm.nih.gov/?term=Khavinson+epitalon+telomerase+human+somatic+cell+2003
[3] Korkushko OV, et al. Geroprotective effect of epithalamine (pineal gland peptide preparation) in elderly subjects with accelerated aging. Bull Exp Biol Med, 2006;142:356–359. https://pubmed.ncbi.nlm.nih.gov/?term=Korkushko+epithalamine+elderly+accelerated+aging+2006