Every claim, graded
The peptide evidence matrix
Every efficacy claim we make about a peptide, in one place, sorted by how good the evidence actually is. Individual peptide pages answer “what does the research say about this compound?” This page answers the question most people actually arrive with: for the thing I care about, which peptide has evidence behind it?
The short version: of 59 graded claims across 24 peptides, 20 reach high or moderate certainty and 26 rest on animal data, cell studies, or uncontrolled human reports. That ratio is the single most useful thing to know about this category, and it is why we publish the weak ratings as prominently as the strong ones.
Which peptides actually have solid human evidence?
Only these carry at least one claim at moderate or high certainty: CJC-1295 / Ipamorelin, MOTS-c, Orforglipron, PT-141 (Bremelanotide), Retatrutide, Semaglutide, Sermorelin, Tesamorelin, Thymosin Alpha-1, Tirzepatide. Every other peptide in our catalogue is supported by weaker evidence than its marketing implies, which does not mean it does not work. It means nobody has shown that it does.
How we assign these ratingsWhat the ratings mean
- High Certainty · 12 claims
- We are very confident the true effect lies close to the estimate. Well-designed human RCTs with consistent, direct outcomes.
- Moderate Certainty · 8 claims
- The true effect is probably close to the estimate, but it could be substantially different. RCTs with limitations, or strong observational evidence.
- Low Certainty · 13 claims
- Confidence is limited; the true effect may be substantially different. Small or short trials, indirect outcomes, or inconsistent results.
- Very Low Certainty · 7 claims
- Very little confidence in the effect estimate. Case series, anecdotal reports, or evidence with multiple serious limitations.
- Preclinical Only · 19 claims
- No human clinical evidence. Effect inferred from animal, in-vitro, or mechanistic data, which often does not translate to humans.
Filter by certainty
Weight loss
10 graded claims across 7 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Orforglipron | Produces about 12.4% average body-weight loss over 72 weeks at 36mg daily in adults with obesity.Adults with BMI ≥30, or ≥27 with at least one weight-related condition, without type 2 diabetes | High | Randomized Controlled TrialNew England Journal of Medicine, 2025 |
| Semaglutide | Produces ~15% mean body-weight loss over 68 weeks at 2.4mg/week in adults with obesity.Adults with BMI ≥30, or ≥27 with at least one weight-related comorbidity, without type 2 diabetes | High | Randomized Controlled Trial (n=1,961)New England Journal of Medicine, 2021 |
| Tesamorelin | Reduces visceral abdominal fat by roughly 15% over 26 weeks.Adults with HIV and excess abdominal fat accumulation associated with antiretroviral therapy | High | Randomized Controlled Trial (n=412)New England Journal of Medicine, 2007 |
| Tirzepatide | Produces 16–22.5% mean body-weight loss over 72 weeks at 5–15mg/week in adults with obesity, with the largest effects at higher doses.Adults with BMI ≥30, or ≥27 with at least one weight-related comorbidity, without type 2 diabetes | High | Randomized Controlled Trial (n=2,539)New England Journal of Medicine, 2022 |
| Tirzepatide | Continued treatment maintains and augments weight loss; stopping after a successful course leads to substantial regain.Adults with obesity who achieved weight loss during an initial open-label tirzepatide lead-in | High | Randomized Controlled Trial (n=670)JAMA, 2024 |
| Tirzepatide | Produces about 13 to 15% mean body-weight loss over 72 weeks at 10 to 15mg/week in adults who have both obesity and type 2 diabetes.Adults with BMI ≥27 and type 2 diabetes (HbA1c 7–10%) | High | Randomized Controlled Trial (n=938)The Lancet, 2023 |
| Retatrutide | Produces roughly 24% average body-weight loss over 48 weeks at 12mg weekly, with phase 3 trials reporting up to about 30%.Adults with obesity (BMI ≥30), or BMI ≥27 with a weight-related condition, without type 2 diabetes | Moderate | Randomized Controlled Trial (n=338)New England Journal of Medicine, 2023 |
| AOD-9604 | Does not produce clinically meaningful weight loss in adults with obesity.Adults with obesity | Low | Randomized Controlled Trial (n=536)Phase 2b obesity trial (Metabolic Pharmaceuticals), 2007 |
| Tesamorelin | Reduces visceral fat in healthy adults without HIV.Healthy adults without HIV-associated lipodystrophy. This is the population most off-label prescriptions target. | Low | Randomized Controlled Trial (n=412)New England Journal of Medicine, 2007 |
| 5-Amino-1MQ | Reduces body fat.No human population has been studied. Evidence is from diet-induced obese mice. | Preclinical | Animal StudySelective NNMT inhibitors reverse high fat diet-induced obesity in mice, 2018 |
Immune function
4 graded claims across 2 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Thymosin Alpha-1 | Does not reduce 28-day mortality in severe sepsis.Adults with severe sepsis | High | Randomized Controlled Trial (n=1,106)Efficacy of Thymosin Alpha 1 in Patients with Severe Sepsis (TESTS), 2023 |
| Thymosin Alpha-1 | Improves sustained virological response in chronic hepatitis B.Adults with chronic hepatitis B infection | Moderate | Randomized Controlled TrialRandomized trials of thymosin alpha-1 in chronic hepatitis B, 1998 |
| Thymosin Alpha-1 | Improves immune function or supports healthy aging in adults without a diagnosed condition.Healthy adults. This is the population most wellness clinics prescribe it to. | Very Low | Randomized Controlled Trial (n=1,106)Efficacy of Thymosin Alpha 1 in Patients with Severe Sepsis (TESTS), 2023 |
| LL-37 | Treats chronic infections or disrupts biofilms in humans.No human population has been studied for this use. | Preclinical | In-VitroLL-37 antimicrobial and antibiofilm activity in vitro |
Cardiovascular outcomes
3 graded claims across 3 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Semaglutide | Reduces major adverse cardiovascular events (CV death, nonfatal MI, nonfatal stroke) by ~20% in adults with overweight/obesity and pre-existing cardiovascular disease.Adults with BMI ≥27 and pre-existing cardiovascular disease, without type 2 diabetes | High | Randomized Controlled Trial (n=17,604)New England Journal of Medicine, 2023 |
| Orforglipron | Improves waist circumference, systolic blood pressure, lipids, and glycemic markers.Adults with obesity or overweight with a weight-related condition | Moderate | Randomized Controlled TrialNew England Journal of Medicine, 2025 |
| Tirzepatide | Does not increase major cardiovascular events and is noninferior to dulaglutide (a GLP-1 with established cardiovascular benefit) for 3-point MACE in adults with type 2 diabetes and established cardiovascular disease. Superiority over dulaglutide was not demonstrated.Adults with type 2 diabetes and established atherosclerotic cardiovascular disease | Moderate | Randomized Controlled Trial (n=13,165)New England Journal of Medicine, 2025 |
Sleep
2 graded claims across 2 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Tirzepatide | Substantially reduces obstructive sleep apnea severity: at 52 weeks it lowered the apnea-hypopnea index by roughly 20 to 24 more events per hour than placebo in adults with moderate-to-severe OSA and obesity.Adults with moderate-to-severe obstructive sleep apnea and obesity, with or without PAP therapy | High | Randomized Controlled TrialNew England Journal of Medicine, 2024 |
| DSIP | Improves sleep quality or increases deep slow-wave sleep.Adults with insomnia and healthy adults | Very Low | Randomized Controlled TrialHuman DSIP sleep studies |
Glycemic control
2 graded claims across 2 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Tirzepatide | Lowers HbA1c by roughly 2.0 to 2.3 percentage points in adults with type 2 diabetes, outperforming semaglutide 1mg head-to-head.Adults with type 2 diabetes inadequately controlled on metformin (SURPASS-2 population) | High | Randomized Controlled Trial (n=1,879)New England Journal of Medicine, 2021 |
| MOTS-c | Administering MOTS-c improves insulin sensitivity, body composition, or metabolic health.No human population has been studied. Evidence is from mice. | Preclinical | Animal StudyCell Metabolism, 2015 |
Libido / sexual function
2 graded claims across 1 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| PT-141 (Bremelanotide) | Increases sexual desire and reduces related distress in premenopausal women with hypoactive sexual desire disorder, with a small effect size.Premenopausal women with acquired, generalized hypoactive sexual desire disorder | High | Randomized Controlled Trial (n=1,267)Obstetrics and Gynecology, 2019 |
| PT-141 (Bremelanotide) | Improves erectile function or sexual desire in men.Adult men. Not an approved population. | Low | Randomized Controlled TrialBremelanotide clinical development program, 2019 |
Kidney outcomes
1 graded claim across 1 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Semaglutide | Reduces the risk of major kidney-disease progression events (kidney failure, a 50% or greater fall in eGFR, or death from kidney or cardiovascular causes) by about 24% in adults with type 2 diabetes and chronic kidney disease.Adults with type 2 diabetes and chronic kidney disease (reduced eGFR with elevated albuminuria) | High | Randomized Controlled Trial (n=3,533)New England Journal of Medicine, 2024 |
Longevity biomarkers
9 graded claims across 7 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| MOTS-c | MOTS-c is released into circulation during exercise in humans.Humans and mice undergoing exercise | Moderate | MechanismNature Communications, 2021 |
| Humanin | Higher circulating humanin levels are associated with longevity in humans.Human cohorts including centenarian offspring and APOE4 carriers | Low | Animal StudyAging, 2020 |
| Epithalon | Extends human lifespan or reduces mortality.Elderly Russian cohorts in uncontrolled studies. | Very Low | Observational StudyRussian cohort studies of Epithalamin and epithalon in elderly subjects |
| 5-Amino-1MQ | Raises cellular NAD+ levels.No human population has been studied. Evidence is from mouse tissue and cell culture. | Preclinical | In-VitroNNMT inhibition and NAD+ salvage, 2018 |
| Epithalon | Activates telomerase and increases telomere length in human cell lines.Human cell lines in culture. No human population has been studied. | Preclinical | In-VitroBiogerontology, 2025 |
| Epithalon | Lengthens telomeres in people who take it.No controlled human study has measured this. | Preclinical | In-VitroBiogerontology, 2025 |
| FOXO4-DRI | Selectively kills senescent cells and improves healthspan measures.No human population has been studied. Evidence is from naturally aged mice and human cells in culture. | Preclinical | Animal StudyCell, 2017 |
| GHK-Cu | Injected GHK-Cu produces systemic anti-aging or regenerative effects.No human population has been studied for injected GHK-Cu. | Preclinical | MechanismInternational Journal of Molecular Sciences, 2018 |
| SS-31 (Elamipretide) | Improves mitochondrial function or physical performance in healthy aging adults.Healthy older adults. This population has not been studied. | Preclinical | Animal StudyElamipretide in aged animal models |
Hormonal
2 graded claims across 2 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| CJC-1295 / Ipamorelin | CJC-1295 with DAC raises growth hormone and IGF-1 levels in healthy adults.Healthy adults aged 21 to 61 | Moderate | Randomized Controlled TrialJournal of Clinical Endocrinology & Metabolism, 2006 |
| Sermorelin | Increases growth hormone release and supports growth in children with growth hormone deficiency.Children with idiopathic growth hormone deficiency and growth failure | Moderate | Federal Register, 2013 |
Liver outcomes
1 graded claim across 1 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Semaglutide | Improves liver histology in MASH: at 72 weeks about 63% of patients had resolution of steatohepatitis without worsening fibrosis and about 37% had fibrosis improvement without worsening steatohepatitis, versus roughly 34% and 22% on placebo.Adults with biopsy-proven metabolic dysfunction-associated steatohepatitis (MASH) and moderate-to-advanced fibrosis (stage 2 or 3) | Moderate | Randomized Controlled Trial (n=800)New England Journal of Medicine, 2025 |
Tissue repair / healing
7 graded claims across 4 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| LL-37 | Accelerates healing of hard-to-heal venous leg ulcers when applied topically.Adults with hard-to-heal venous leg ulcers receiving compression therapy | Low | Randomized Controlled Trial (n=148)Wound Repair and Regeneration, 2021 |
| TB-500 | Full-length thymosin beta-4 eye drops reduce discomfort and corneal damage in dry eye disease.Adults with moderate to severe dry eye disease, treated with topical full-length Tb4 (not TB-500) | Low | Randomized Controlled Trial (n=72)Clinical Ophthalmology, 2015 |
| TB-500 | Speeds healing of chronic pressure and venous stasis ulcers.Adults with chronic pressure or venous stasis ulcers, treated with topical full-length Tb4 gel | Low | Randomized Controlled Trial (n=143)RegeneRx phase 2 programmes in pressure ulcers and venous stasis ulcers |
| BPC-157 | Reduces chronic knee pain after intra-articular injection.Adults with chronic knee pain, in a small retrospective case series | Very Low | Case Series (n=16)Alternative Therapies in Health and Medicine, 2021 |
| BPC-157 | Accelerates healing of tendon, ligament, muscle, and bone injuries.No adequately controlled human population has been studied. Evidence is from rodent and other animal injury models. | Preclinical | Systematic ReviewHSS Journal, 2025 |
| GHK-Cu | Accelerates wound healing and tissue remodelling.No adequately controlled human population has been studied. Evidence is from cell culture and animal wound models. | Preclinical | In-VitroFEBS Letters, 1988 |
| TB-500 | Accelerates healing of muscle, tendon, and ligament injuries when injected.No human population has been studied for this use. Evidence is from animal models. | Preclinical | Animal StudyNature, 2011 |
Cognitive function
6 graded claims across 4 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Tesamorelin | Improves executive function in older adults, including those with mild cognitive impairment.Adults aged 55 to 87, both cognitively healthy and with mild cognitive impairment | Low | Randomized Controlled Trial (n=152)Archives of Neurology, 2012 |
| Selank | Reduces anxiety without sedation or dependence.Adults with generalized anxiety disorder, as studied in Russian clinical practice | Very Low | Randomized Controlled TrialRussian clinical studies of Selank in anxiety |
| Semax | Improves functional recovery after ischemic stroke.Adults recovering from ischemic stroke | Very Low | Observational Study (n=110)Semax in post-stroke rehabilitation |
| Humanin | Administering humanin protects neurons or prevents cognitive decline.No human population has been studied. Evidence is from cell culture and animal models. | Preclinical | In-VitroProceedings of the National Academy of Sciences, 2001 |
| Selank | Improves memory, focus, or cognitive performance.No adequately controlled human population has been studied for this outcome. | Preclinical | Animal StudySelank effects on BDNF and neurotransmitter gene expression |
| Semax | Improves memory, focus, or cognitive performance in healthy adults.Healthy adults. This is the population it is most heavily marketed to in the West. | Preclinical | Animal StudySemax effects on BDNF expression in rat hippocampus |
Muscle preservation
3 graded claims across 3 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Semaglutide | May contribute to lean-mass loss; structured resistance training and adequate protein are commonly recommended to mitigate this.Adults losing weight on semaglutide | Low | Randomized Controlled Trial (n=1,961)New England Journal of Medicine, 2021 |
| SS-31 (Elamipretide) | Improves muscle strength in patients with Barth syndrome.Patients with genetically confirmed Barth syndrome weighing at least 30kg | Low | Randomized Controlled Trial (n=12)US Food and Drug Administration, 2025 |
| Tirzepatide | Body-composition data show fat mass loss substantially exceeds lean mass loss, but lean mass still declines and is rarely studied with structured resistance training in tirzepatide users.Adults losing weight on tirzepatide | Low | Randomized Controlled Trial (n=2,539)New England Journal of Medicine, 2022 |
Skin
2 graded claims across 2 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| GHK-Cu | Improves the appearance of photoaged skin, including fine lines, density, and firmness, when applied topically.Adults with photoaged facial skin using a topical GHK-Cu cosmetic preparation | Low | Systematic ReviewBioImpacts, 2025 |
| KPV | Reduces skin inflammation when applied topically.No human population has been studied in a controlled trial. | Preclinical | In-VitroAnti-inflammatory activity of alpha-MSH C-terminal tripeptide, 2008 |
Gut health
2 graded claims across 2 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| BPC-157 | Heals the gut lining and protects against NSAID-induced damage.No human population has been studied. Evidence is from rodent models of ulcer, colitis, and NSAID injury. | Preclinical | Systematic ReviewHSS Journal, 2025 |
| KPV | Reduces intestinal inflammation.No human population has been studied. Evidence is from mouse colitis models and cultured intestinal cells. | Preclinical | Animal StudyKPV in DSS and TNBS-induced colitis models, 2013 |
Other
3 graded claims across 3 peptides
| Peptide | Claim | Certainty | Strongest evidence |
|---|---|---|---|
| Retatrutide | Reduces knee osteoarthritis pain in adults with obesity.Adults with obesity and symptomatic knee osteoarthritis | Low | Randomized Controlled TrialEli Lilly investor release, 2025 |
| Sermorelin | Improves body composition, energy, or markers of aging in healthy adults.Healthy adults without growth hormone deficiency. This is the population sermorelin is most often prescribed to today. | Very Low | FDA Orange Book, 1997 |
| CJC-1295 / Ipamorelin | The CJC-1295 and ipamorelin combination improves body composition, recovery, or sleep quality.No population has been studied. The combination has never been evaluated in a clinical trial. | Preclinical | Randomized Controlled TrialInternational Journal of Colorectal Disease, 2014 |
Browse all peptides
The full catalogue with regulatory status, dosing, and safety for each compound.
The grading rubric
How each tier is assigned, and the GRADE factors that push a rating down.
This page is generated from the same graded claims shown on each peptide page, so it cannot drift out of sync with them. Ratings are reviewed monthly. Nothing here is medical advice.