Evidence

Peptide Research Database

Every entry summarizes a specific study: what was tested, in whom, what changed, and where the result stops being reliable. Evidence strength is scored 1–5 based on design, sample size, and replication — not on how promising the conclusion sounds.

• RCT · 2024 · JAMA

  Continued Treatment with Tirzepatide vs Withdrawal on Weight Maintenance (SURMOUNT-4)

  Withdrawal after 36 weeks of open-label treatment produced 14% weight regain, while continued treatment produced further loss — evidence that obesity pharmacotherapy behaves like chronic-disease therapy.

  Tirzepatide

• RCT · 2023 · New England Journal of Medicine

  Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT)

  17,604 participants over a mean 39.8 months showed a 20% relative reduction in major adverse cardiovascular events — the first hard-outcome proof that a weight-loss peptide reduces cardiovascular death.

  Semaglutide

• RCT · 2022 · New England Journal of Medicine

  Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1)

  2,539 participants; 20.9% mean weight reduction at 72 weeks on the 15 mg dose, approaching bariatric-surgery territory.

  Tirzepatide

• RCT · 2021 · New England Journal of Medicine

  Once-Weekly Semaglutide 2.4 mg in Adults with Overweight or Obesity

  The trial that reset expectations for pharmacologic weight loss: 1,961 participants, 68 weeks, and a 14.9% mean reduction in body weight versus 2.4% on placebo.

  Semaglutide

• Meta-analysis · 2025 · Obesity Reviews

  Body Composition Changes with GLP-1 Receptor Agonists: Lean Mass Meta-analysis

  Roughly 25–40% of total weight lost on incretin therapy is lean mass unless resistance training and protein intake are addressed — the most practically important open question in the field.

  Semaglutide · Tirzepatide

• Phase II · 2023 · New England Journal of Medicine

  Triple–Hormone-Receptor Agonist Retatrutide for Obesity

  24.2% mean weight loss at 48 weeks on 12 mg weekly — the largest figure reported for any pharmacologic agent to date.

  Retatrutide

• RCT · 2019 · The Lancet HIV

  Tesamorelin Reduces Hepatic Fat in HIV-Associated NAFLD

  A GHRH analogue reduced liver fat by roughly 37% relative to placebo over 12 months, with less fibrosis progression on biopsy.

  Tesamorelin

• Cohort · 2024 · Analytical toxicology literature (multiple analyses)

  Identity and Purity Testing of Consumer-Marketed Research Peptides

  Mass-spectrometry surveys of grey-market peptide vials repeatedly find under-dosing, wrong sequences, bacterial endotoxin, and undeclared excipients in a substantial share of samples.

  BPC-157 · TB-500 · CJC-1295

• Review · 2015 · BioMed Research International

  GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration

  Synthesizes gene-expression work showing GHK-Cu modulates over 4,000 human genes toward a younger transcriptional profile, alongside small clinical dermatology results.

  GHK-Cu

• RCT · 2013 · Critical Care

  Efficacy of Thymosin Alpha 1 in Severe Sepsis (ETASS)

  A 361-patient multicenter RCT reporting reduced 28-day mortality with thymosin alpha-1 added to standard sepsis care.

  Thymosin Alpha-1

• Phase II · 2006 · Journal of Clinical Endocrinology & Metabolism

  Pharmacokinetics, Pharmacodynamics, and Safety of CJC-1295 in Healthy Adults

  Single doses produced sustained 2–10x GH increases and 1.5–3x IGF-1 elevations lasting up to 6 days, establishing the long-acting profile.

  CJC-1295

• Animal study · 2018 · Journal of Applied Physiology / preclinical series

  Stable Gastric Pentadecapeptide BPC 157 and Tendon Healing Mechanisms

  Rat Achilles-tendon models show accelerated fibroblast outgrowth and improved biomechanical strength with BPC-157, mediated through VEGFR2 and FAK-paxillin signaling.

  BPC-157

• RCT · 2011 · Zhurnal Nevrologii i Psikhiatrii

  Semax in Acute Ischemic Stroke: Neurological Recovery Outcomes

  Russian trials report improved neurological scores when intranasal Semax is added to standard stroke care within the acute window.

  Semax

• In vitro · 2003 · Bulletin of Experimental Biology and Medicine

  Epithalon Peptide Induces Telomerase Activity and Telomere Elongation in Human Somatic Cells

  The foundational claim behind Epitalon's longevity reputation: telomerase activation and telomere elongation in cultured human fibroblasts.

  Epitalon