Master Peptide Benefits & Side-Effects Comparison Table (2026)

This is the flagship reference for peptide coverage: a single, scannable map of what the published evidence actually shows, separating the handful of peptides with genuine human randomized-trial support from the much larger group whose claims rest on animal data, mechanism, or marketing. Every efficacy claim is graded for evidence strength, and human-trial evidence is kept rigorously separate from animal, in-vitro, and anecdotal signals.

This article is informational and editorial content for research and educational purposes only. It is not medical advice, not a protocol, and not a sourcing or dosing guide. Many substances discussed are not FDA-approved and are sold as 'research chemicals, not for human use' with no established human safety floor; several are prohibited in sport. Consult a licensed clinician before any health decision.

How should you read peptide evidence grades?

The grade describes the strength of human efficacy evidence for the lead claim — not how popular, how mechanistically plausible, or how heavily marketed a compound is. This distinction is the entire point of the table, because the field's marketing routinely conflates mechanism with proof.

A crucial nuance: a grade can attach to a negative finding. AOD-9604 carries Grade-A human evidence — six RCTs across 893 subjects — that it does not produce clinically meaningful weight loss.9 The same is true of oglufanide/thymogen in Kaposi sarcoma14 and aviptadil (VIP) in COVID-19 respiratory failure, where a large trial (n=461) showed no benefit.15 High-quality evidence of no effect is still high-quality evidence.

Which peptides are genuinely proven in humans?

The evidence-backed minority clusters in a few classes, and it is dominated by FDA-approved prescription drugs. The most rigorously proven class is the incretin and amylin metabolic peptides. Semaglutide and tirzepatide anchor it with large Phase 3 and cardiovascular-outcome programs; in a head-to-head RCT, tirzepatide outperformed semaglutide on both glycemic control and weight loss.1 The class extends to dulaglutide, liraglutide, exenatide (with a 14,752-patient cardiovascular outcome trial),3 and the investigational triple agonist retatrutide, which produced the largest reported pharmacologic weight loss to date.20 You can read the full FDA labeling for tirzepatide directly at the FDA drug label database, and current diabetes standards of care summarize where each agent fits.4

Beyond metabolism, the Grade-A roster includes the bone-anabolic peptides teriparatide and abaloparatide, which reduce fractures — abaloparatide cut new vertebral fractures by roughly 86% in the ACTIVE trial.5 PT-141 (bremelanotide) is FDA-approved for premenopausal hypoactive sexual desire disorder on the strength of the RECONNECT program.6 Elamipretide (SS-31) earned accelerated approval for Barth syndrome, and teduglutide is approved for short bowel syndrome. These share a defining trait: they are prescription medicines used under clinical supervision, not compounds sold direct to consumers.

Why are the most popular peptides graded lowest?

The tissue-repair and growth-hormone classes are among the most heavily marketed 'wellness' peptides — yet their flagship claims are largely preclinical. BPC-157, the stable gastric pentadecapeptide, has an unusually deep and coherent animal evidence base for tendon, gut, and wound healing, but no completed human RCT exists; a 2025 systematic review found extensive preclinical work and only a single clinical study.7 The first controlled efficacy trial, a Phase 2 hamstring-strain RCT, is registered as NCT07437547 but had not reported as of mid-2026.8 That caps it at Grade C. TB-500 shares the pattern: strong preclinical signals, no human efficacy data, with the only human trials belonging to full-length thymosin β4 in corneal disease (Grade B for a different molecule).

The growth-hormone secretagogue class illustrates the trap. Diagnostic GH provocation is well-proven, but chronic anti-aging, recovery, and body-composition claims are largely unproven, and even the best-studied member, the oral secretagogue MK-677, raised growth hormone and lean mass in a two-year RCT while its disease and functional endpoints came back null — plus an insulin-resistance and heart-failure safety signal.10 Growth factors and IGF analogs (follistatin, IGF-1 LR3, MGF, PEG-MGF) sit at Grade C or D and are uniformly banned in sport. Grade B occupies the honest middle: the mitochondrial-derived peptide MOTS-c has human biomarker-association data but only preclinical efficacy,11 and LL-37 has small topical wound-healing RCTs.12

What is the 2026 legal and anti-doping status?

The regulatory picture is bifurcated. Grade-A peptides are FDA-approved drugs. Most Grade C/D compounds are not approved and are sold as research chemicals with no quality control — vials have tested positive for endotoxins, heavy metals, and inaccurate dosing.19 The 503A compounding landscape was in active flux through 2026: the FDA moved many peptides into Category 2 in September 2023, then removed several on April 15, 2026 — but because the nominations were withdrawn, not because the substances were found safe. Removal from Category 2 does not equal Category 1 status and does not authorize compounding.18

For athletes, the picture is stricter. Many popular peptides are prohibited at all times: BPC-157 sits under WADA category S0 with no Therapeutic Use Exemption,17 the GH-secretagogue class under S2.2, and growth factors under S2.3. Numerous unlisted longevity peptides are captured by the S0 non-approved-substance catch-all. Because strict liability applies, any tested athlete or military service member should verify status with their anti-doping organization before considering any of these agents.

Bottom line. The single most important pattern in the peptide field is the inverse relationship between marketing volume and evidence quality. A small, rigorously proven set of Grade-A peptides consists of FDA-approved prescription medicines; the aggressively promoted consumer 'peptides' overwhelmingly rest on animal data, mechanism, or anecdote. This document maps that evidence terrain — it does not recommend, endorse, or instruct the use of any agent. Regulatory facts here are current as of June 2026; the July 2026 PCAC outcome was pending at the time of writing and should be re-verified after that date. Consult a licensed clinician.