Peptide guide
Everything you need to know about peptides
From FDA-approved GLP-1s to trending “research peptides,” 42 profiles graded by real evidence — what each does, what studies show, regulatory status, and safety.
Last reviewed October 2026 · Educational only, not medical advice.
Peptide basics
How we grade evidence
Supported by regulator-approved labeling or consistent large human trials.
Supported by published human trials, but not approved for this use or data are limited.
Animal, cell, or very small/uncontrolled human studies only.
Reported online or in practice; not validated by controlled research.
Most peptides marketed online are not FDA-approved. Never self-inject products labeled “research use only.”
Essential reads
6 min read
How to read peptide evidence
Why a rat study isn't a human result, and how to tell an approved dose from a forum dose.
The evidence ladder
Regulator-approved labels sit at the top: they reflect large randomized trials reviewed by agencies like the FDA or EMA. Below that are published human trials, then animal and cell studies, and finally anecdotal reports. Most peptides sold online sit on the bottom two rungs.
Animal results rarely translate
Doses, healing timelines, and biology differ between rodents and people. Many compounds that work in mice never show benefit in human trials — AOD-9604 is a well-documented example.
Watch for single-lab evidence
When nearly all studies on a compound come from one research group, independent replication is missing. This applies to BPC-157 and Epitalon.
Approved ≠ approved for your use
Tesamorelin is FDA-approved — but only for HIV-associated lipodystrophy. Off-label use relies on weaker evidence.
5 min read
Compounded vs approved peptides
What compounding pharmacies can and cannot guarantee, and what the FDA's Category 2 list means.
What compounding is
Pharmacies may prepare customized medications for individual patients. Compounded drugs are not FDA-approved, which means the agency has not verified their safety, effectiveness, or quality.
The FDA Category 2 list
In 2023 the FDA placed several peptides — including BPC-157, TB-4 fragments, GHK-Cu (injectable), KPV, MOTS-c, and Ipamorelin/CJC-1295 — on a list of bulk substances that may present significant safety risks, restricting their use in US compounding.
Research-use-only products
Products labeled ‘not for human consumption’ have no quality obligations for human use. Independent analyses have found under-dosing, contamination, and wrong substances.
Questions to ask
Is the active ingredient pharmaceutical grade? Is there a certificate of analysis from an independent lab? Is a licensed clinician supervising?
7 min read
GLP-1 medicines: the essentials
Semaglutide, tirzepatide, and what comes next — effectiveness, side effects, and what happens when you stop.
How they work
GLP-1–based drugs mimic gut hormones that signal fullness, slow stomach emptying, and help regulate blood sugar.
How well they work
In 68–72 week trials, semaglutide 2.4 mg produced ~15% mean weight loss and tirzepatide 15 mg ~21%. Individual response varies widely.
Common side effects
Nausea, vomiting, diarrhea, and constipation are common, especially during dose increases. Gallbladder problems and pancreatitis are less common but important risks.
Stopping
Most people regain a substantial portion of lost weight after stopping, so these are generally considered long-term treatments.
4 min read
Injection basics & safety
General principles for subcutaneous medicines prescribed by a clinician.
Only under supervision
This guide is general education. Follow the instructions from your prescriber and pharmacist for any injectable medication.
Storage
Most peptides require refrigeration and protection from light. Never use a product that has been frozen unless labeled for it, or that looks cloudy when it should be clear.
Sterility
Use new sterile needles every time, rotate injection sites, and dispose of sharps in an approved container.
Warning signs
Seek medical care for spreading redness, fever, severe abdominal pain, difficulty breathing, or facial swelling.
Peptide encyclopedia A–Z
42 results
Acetyl-L-Carnitine
ALCAR
Amino-acid derivative (not a peptide) involved in fatty-acid transport, with modest human data.
AOD-9604
hGH fragment 177–191 analogue
Modified growth-hormone fragment that failed to show meaningful weight loss in phase 2b trials.
BPC-157
Body Protection Compound-157 · pentadecapeptide
The most-discussed repair peptide — extensive rodent data, almost no published human trials.
BPC-157 + TB-500
“Wolverine stack”
Popular recovery combination — no human trials of either component for musculoskeletal injury, or of the combination.
Cagrilintide
Long-acting amylin analogue · sold as “Amylix”
Investigational long-acting amylin analogue studied alone and combined with semaglutide (CagriSema).
CJC + Ipamorelin + DSIP
Adds DSIP to the GH-release pairing; unstudied as a combination.
CJC-1295
Modified GRF (1-29) without DAC (“Mod GRF”) · with DAC variant
GHRH analogue that raises GH and IGF-1; the DAC version had human phase 1/2 data before development stopped.
CJC-1295 + Ipamorelin
Popular GHRH + ghrelin-mimetic pairing; rationale is physiological, but combination trials don't exist.
Dihexa
PNB-0408
Angiotensin IV–derived research compound that improved cognition in rats; no human trials.
DSIP
Delta Sleep-Inducing Peptide
Nonapeptide isolated in 1977 from rabbits; small human trials show inconsistent effects on sleep.
EDTA + Xylitol Nasal Spray
Nasal hygiene spray (not a peptide). Xylitol sprays have small studies for sinus symptoms.
Enclomiphene
trans-clomiphene citrate
Oral SERM (not a peptide) that raises testosterone in secondary hypogonadism while preserving sperm counts.
Epitalon
Epithalon · Ala-Glu-Asp-Gly
Synthetic tetrapeptide from Russian gerontology research; claims rest on a small group's studies.
GHK-Cu (Copper Peptide)
Glycyl-L-histidyl-L-lysine copper
Naturally occurring copper tripeptide with modest clinical evidence for topical skin aging — injectables are unstudied.
Glow Triple Peptide
BPC-157 / TB-500 / GHK-Cu
Compounded three-peptide blend marketed for skin and repair; not studied as a combination.
Humanin
Mitochondria-derived peptide discovered in Alzheimer's research; human administration has not been studied.
IGF-1 LR3
Long R3 IGF-1
Modified long-acting IGF-1 used in cell culture; never tested in humans. Mecasermin (Increlex) is the approved IGF-1.
Ipamorelin
Selective ghrelin-receptor agonist that releases GH without large cortisol/prolactin effects; failed in phase 2 for ileus.
Kisspeptin
Kisspeptin-10 / -54
Upstream regulator of GnRH studied for fertility, hypogonadism, and sexual brain processing.
KLOW Blend
BPC-157 / TB-500 / GHK-Cu / KPV
Four-peptide compounded stack adding anti-inflammatory KPV; no clinical data on the combination.
KPV
Lys-Pro-Val · α-MSH(11-13)
Anti-inflammatory tripeptide from α-MSH, active in mouse colitis models; no human trials.
Melanotan II
MT-II · listed as “MII”
Unapproved non-selective melanocortin agonist used for tanning; linked to safety warnings from regulators.
MGF (Mechano Growth Factor)
IGF-1Ec splice variant · PEG-MGF
IGF-1 splice variant expressed in muscle after loading; evidence is limited to cell and animal studies.
MOTS-c
Mitochondrial ORF of the 12S rRNA type-c
Mitochondria-derived peptide that improves insulin sensitivity and exercise capacity in mice — human data are minimal.
NAD+
Nicotinamide adenine dinucleotide
Essential coenzyme (not a peptide) that declines with age; human benefit of supplementation remains unproven.
Oxytocin
Pitocin (IV)
Hypothalamic hormone approved for labour induction; intranasal social and sexual effects remain mixed.
Peptide Golden Gut Support
BPC-157 + KPV + curcumin + L-glutamine
Oral capsule blend; curcumin and glutamine have modest human data, the peptides do not.
PT-141 (Bremelanotide)
Vyleesi
FDA-approved melanocortin agonist for low sexual desire in premenopausal women.
PT-141 + Oxytocin
Compounded intranasal combination of bremelanotide and oxytocin. The combination itself has not been studied.
Retatrutide
LY3437943 · sold as “GLP-X3”
Investigational GIP / GLP-1 / glucagon triple agonist with the largest weight reductions reported in a phase 2 obesity trial.
Selank
Tuftsin analogue · TP-7
Russian-approved anxiolytic peptide; small trials suggest benzodiazepine-like calm without sedation.
Semaglutide
Ozempic · Wegovy · Rybelsus
FDA-approved GLP-1 receptor agonist for type 2 diabetes, chronic weight management, and cardiovascular risk reduction.
Semax
ACTH(4-10) analogue · Met-Glu-His-Phe-Pro-Gly-Pro
Russian-approved nootropic and neuroprotective nasal peptide; minimal research outside Russia.
Semax + Oxytocin
Compounded nasal combination; no published human data on the pairing.
Semax + Selank
Compounded focus-plus-calm nasal blend; not studied as a combination.
Sermorelin
GRF (1-29) · formerly Geref
First 29 amino acids of GHRH; previously FDA-approved for pediatric GH deficiency, discontinued in 2008.
SLU-PP-332
Estrogen-related receptor (ERR) agonist · listed as “SLUPP-332”
Small-molecule ERR agonist (not a peptide) studied as an exercise mimetic in mice only.
SS-31 (Elamipretide)
Forzinity · MTP-131 · Bendavia
Mitochondria-targeting tetrapeptide; received FDA accelerated approval for Barth syndrome in 2025.
TB-500 / Thymosin Beta-4
Tβ4 · also listed as “Thymosin Beta”
Actin-binding peptide; full-length Tβ4 has phase 2 data in eye and wound healing. TB-500 fragments have none.
Tesamorelin
Egrifta
FDA-approved GHRH analogue for reducing excess abdominal fat in HIV-associated lipodystrophy.
Thymosin Alpha-1
Thymalfasin · Zadaxin
Immunomodulating thymic peptide approved in 30+ countries for hepatitis B/C and as a vaccine adjuvant.
Tirzepatide
Mounjaro · Zepbound
FDA-approved dual GIP/GLP-1 agonist for type 2 diabetes, obesity, and obstructive sleep apnea.
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