Peptide research, without the hype.
Sixty-five deep guides to peptide medicines and experimental compounds people actually search for — what the published trials found, what the evidence does not support, and where each compound stands with regulators. Every claim links to its source on PubMed.
How to read these guides
Most peptide content online falls into one of two traps: it either sells you something, or it repeats a claim that traces back to a mouse study from 2003. These guides are built to avoid both.
Each article separates four very different things that peptide marketing routinely blurs together: FDA-approved drugs with phase 3 trial programs behind them; investigational drugs still in trials and not legally sold to consumers; compounded or off-label prescriptions; and unapproved research chemicals sold online with animal-only data and no purity oversight. Semaglutide and BPC-157 both get called "peptides" — they are not in the same universe of evidence.
Where the human evidence is thin, we say so. Where a trial reported a number, we give the number, the trial, and the link. And nowhere on this site will you find a dose, a protocol, or a cycle — that is a conversation for you and a clinician, not a website.
GLP-1 & metabolic peptides
The best-evidenced corner of the field. These are prescription medications with large randomized trials, real cardiovascular-outcome data, and well-characterized side effects — plus the investigational next generation.
GLP-1 agonists explained
The whole drug class in one place: how GLP-1 signaling works, every agent from exenatide to retatrutide, what the outcome trials showed, and the class-wide warnings.
Read the guide → Pillar guidePeptides for weight loss
An honest evidence tier list — which weight-loss peptides have phase 3 trials behind them, and which are sold online on the strength of animal data alone.
Read the guide → InvestigationalRetatrutide
The triple GIP/GLP-1/glucagon agonist behind the biggest phase 2 weight-loss numbers yet recorded — and why it is still not something you can legally buy.
Read the guide → FDA approvedTirzepatide
SURMOUNT-1, SURPASS, and the head-to-head that put it ahead of semaglutide — plus side effects and what happens when people stop.
Read the guide → FDA approvedSemaglutide
The STEP program, the SELECT cardiovascular results, the weight regain data after withdrawal, and the compounded-semaglutide mess.
Read the guide → FDA approvedOzempic
What Ozempic is approved for, why so many people take it off-label for weight, and how it differs from Wegovy despite being the same molecule.
Read the guide → FDA approvedWegovy
Semaglutide 2.4 mg for chronic weight management — trial results, eligibility, the cardiovascular indication, and the cost reality.
Read the guide → FDA approvedMounjaro
Tirzepatide under its diabetes brand: the SURPASS trials, how dual GIP+GLP-1 differs from GLP-1 alone, and approval status by region.
Read the guide → FDA approvedLiraglutide
The daily GLP-1 that started the modern weight-management era, what SCALE actually showed, and why weekly agents overtook it.
Read the guide → InvestigationalCagrilintide
The long-acting amylin analog and the CagriSema combination — a different satiety pathway, and what the phase 3 data looked like.
Read the guide → Weak evidenceAOD9604
The growth-hormone fragment marketed as a fat burner. The animal lipolysis data is real; the human weight-loss evidence is not what the ads imply.
Read the guide →Repair & recovery peptides
The most hyped category online and the thinnest in human trials. These guides lay out exactly what the preclinical work shows and where the clinical evidence stops.
BPC-157
Hundreds of animal studies on tendon, gut and nerve healing — and effectively zero published human RCTs. Plus its FDA and WADA status.
Read the guide → PreclinicalTB-500
What TB-500 actually is versus real thymosin beta-4, the actin-binding mechanism, and why athletes should know it is on the prohibited list.
Read the guide → Topical evidenceGHK-Cu
The copper tripeptide with a genuine cosmetic-science evidence base — and a much weaker one behind the injectable claims.
Read the guide →Growth-hormone axis peptides
Secretagogues and GHRH analogs sold widely by anti-aging clinics. One of them is FDA approved for a narrow indication; the rest are not approved for anything.
Ipamorelin
The selective growth-hormone secretagogue: what the original selectivity research showed, and why it has no approved human indication.
Read the guide → Not approvedCJC-1295
The DAC vs no-DAC distinction most articles get wrong, the human pharmacology data, and its FDA compounding status.
Read the guide → CompoundedSermorelin
Once FDA approved as Geref, withdrawn for commercial reasons, now everywhere in anti-aging clinics. What the real clinical evidence covers.
Read the guide → FDA approvedTesamorelin
The one GHRH analog with an FDA approval — for HIV-associated visceral fat. Why its evidence base dwarfs the rest of the category.
Read the guide →Brain, longevity & cellular peptides
Nootropic and anti-aging compounds, several approved in Russia but nowhere else, and several whose entire reputation rests on cell-line work.
Semax
The ACTH(4-10) analog used clinically for stroke in Russia, the BDNF research behind it, and the study-quality caveats worth knowing.
Read the guide → Approved in RussiaSelank
A tuftsin-derived anxiolytic compared head-to-head with a benzodiazepine — and the limits of that evidence base outside Russia.
Read the guide → Weak evidenceEpitalon
Telomeres, telomerase, and the contested lifespan studies — including the mouse experiment that found no life-span effect at all.
Read the guide → PreclinicalMOTS-c
The mitochondrial-derived peptide sold as an exercise mimetic. What the AMPK research shows and what the human data does not.
Read the guide → SupplementNAD+
Not a peptide — but searched alongside them constantly. What NR and NMN trials actually measured, and the FDA's position on NMN.
Read the guide → InvestigationalSS-31 / elamipretide
The cardiolipin-binding mitochondrial peptide with a real clinical program — and a trial record that is more mixed than the marketing suggests.
Read the guide →Other high-demand peptides
Three compounds that generate enormous search volume for very different reasons — one approved by the FDA, one immunomodulator approved abroad, and one with a documented harm record.
PT-141 (bremelanotide)
Approved as Vyleesi for HSDD in premenopausal women. The RECONNECT trial effect size, side effects, and the unapproved male market.
Read the guide → Documented harmsMelanotan 2
The illegal tanning peptide with published case reports of changing moles, melanoma, rhabdomyolysis and priapism. Read before anything else.
Read the guide → Approved abroadThymosin alpha-1
An immunomodulator approved in dozens of countries outside the US, with sepsis meta-analyses and antiviral research behind it.
Read the guide →30 more peptide research guides
The expanded library covers established peptide medicines and heavily searched experimental compounds. Each page separates approved use, human research, preclinical evidence, and unsupported marketing.
Metabolic peptide medicines
Established and emerging peptide medicines for diabetes, rare genetic obesity, and appetite regulation, separated by indication and evidence strength.
Pramlintide
the amylin analog used with mealtime insulin for type 1 and type 2 diabetes. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineSetmelanotide
the MC4R agonist for selected rare genetic causes of severe obesity. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineExenatide
the exendin-4 GLP-1 drug behind Byetta and Bydureon. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineDulaglutide
the once-weekly GLP-1 medicine sold as Trulicity. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineLixisenatide
the short-acting GLP-1 agonist with a strong post-meal glucose effect. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide →Growth and performance peptides
Frequently marketed GH-axis and muscle-growth compounds, with a hard line between endocrine pharmacology and unsupported performance claims.
GHRP-2
a synthetic ghrelin-receptor agonist also called pralmorelin. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineGHRP-6
a ghrelin-mimicking hexapeptide studied for GH release and appetite signaling. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineHexarelin
a potent synthetic GH secretagogue with ghrelin-receptor and CD36 biology. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineIGF-1 LR3
a long-acting IGF-1 analog marketed online despite minimal human evidence. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicinePEG-MGF
the pegylated mechano growth factor sold for recovery without clinical trials. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineFollistatin-344
a myostatin-binding protein found in black-market performance products. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide →Brain and longevity peptides
Neuroactive and mitochondrial peptides whose reputations often run far ahead of controlled human evidence.
Humanin
a mitochondrial-derived peptide studied for cytoprotection and metabolism. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineDSIP
delta sleep-inducing peptide and the limits of its sleep claims. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineDihexa
an angiotensin-IV-derived HGF/c-Met compound studied in memory models. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicinePinealon
the Glu-Asp-Arg tripeptide marketed for cognition and aging. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineCerebrolysin
a porcine brain-derived peptide mixture studied in stroke and dementia. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide →Immune and repair peptides
Endogenous immune-signaling peptides with convincing laboratory biology but limited evidence as stand-alone human therapies.
KPV Peptide
the Lys-Pro-Val fragment of alpha-MSH studied in colitis models. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineLL-37
the human cathelicidin that links antimicrobial defense and inflammation. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide →Reproductive hormone peptides
Peptides that act on the hypothalamic-pituitary-gonadal axis, from experimental kisspeptin protocols to established GnRH agonists.
Kisspeptin
the KISS1 neuropeptide that activates GnRH and reproductive hormone release. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineLeuprolide
the GnRH agonist used for prostate cancer, endometriosis, fibroids, and precocious puberty. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineTriptorelin
a long-acting GnRH agonist used in prostate cancer and central precocious puberty. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide →Gastrointestinal peptide medicines
Peptide medicines that act locally in the gut or support intestinal adaptation, with randomized trials and narrow approved indications.
Teduglutide
the GLP-2 analog that can reduce parenteral-support needs in short bowel syndrome. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineLinaclotide
the locally acting peptide used for IBS-C and chronic idiopathic constipation. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicinePlecanatide
the uroguanylin analog used for chronic constipation and IBS-C. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide →Specialist peptide medicines
Approved peptide therapies used in porphyria, neuroendocrine disease, osteoporosis, and severe chronic pain.
Afamelanotide
the alpha-MSH analog implant that increases light tolerance in EPP. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineOctreotide
the somatostatin analog used in acromegaly and hormone-secreting tumors. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineLanreotide
the long-acting somatostatin analog used in acromegaly and GEP-NETs. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineTeriparatide
the PTH(1-34) anabolic peptide used for people at high fracture risk. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineAbaloparatide
the PTHrP analog used as anabolic therapy for high-risk osteoporosis. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide → Established medicineZiconotide
the synthetic cone-snail peptide used intrathecally for severe chronic pain. Evidence, risks, approval status, FAQs, and direct PubMed links.
Read the guide →Head-to-head comparisons
The direct comparisons people search before a clinic appointment — built on head-to-head trials where they exist, and explicit about when they do not.
Tirzepatide vs semaglutide
The only large randomized comparison of the two leading weight-loss drugs, plus the glycemic head-to-head and the cost trade-off.
Compare → Same moleculeOzempic vs Wegovy
Identical drug, different brand, dose ceiling and indication. Which one gets covered, which gets prescribed off-label, and why it matters.
Compare → Head-to-head trialMounjaro vs Ozempic
Dual agonist against single agonist under their diabetes brands — A1c, weight, side effects and coverage.
Compare → Cross-trialRetatrutide vs tirzepatide
Triple versus dual agonist. The phase 2 numbers, why comparing across trials is unreliable, and where the approval gap stands.
Compare → Preclinical bothBPC-157 vs TB-500
The two most-searched healing peptides side by side: different mechanisms, the same missing human trials, the same regulatory problems.
Compare →Practical guides
The questions that come after the research: what the law says, why clinicians care about site rotation, and how to keep a record you can actually hand to a doctor.
Are peptides legal?
FDA approval vs compounding vs "research use only" vs the WADA list — the regulatory map, jurisdiction by jurisdiction.
Read the guide → Clinical backgroundPeptide injection sites
Why site rotation is studied at all, what the lipohypertrophy literature shows, and how people keep rotation records between appointments.
Read the guide → PracticalHow to track peptides
Weekly cadences, titration dates, side-effect timing. What adherence research says about reminders, and how to build a record worth keeping.
Read the guide →Landmark clinical trials
Standalone breakdowns of the trials the drug guides keep citing — design, population, primary and secondary results, and limitations, each with the PubMed record and ClinicalTrials.gov registration.
STEP 1
The trial that set the modern benchmark: −14.9% mean weight loss over 68 weeks with weekly semaglutide 2.4 mg.
Read the breakdown → Tirzepatide · NEJM 2022SURMOUNT-1
Tirzepatide's 72-week obesity trial — up to −20.9% at the 15 mg dose, with 57% reaching ≥20% loss.
Read the breakdown → Head-to-head · NEJM 2025SURMOUNT-5
The direct comparison: tirzepatide −20.2% vs semaglutide −13.7% at 72 weeks.
Read the breakdown → Cardiovascular · NEJM 2023SELECT
17,604 patients: semaglutide cut major cardiovascular events ~20% (HR 0.80) — the first weight drug to show it.
Read the breakdown → Investigational · NEJM 2025REDEFINE 1
CagriSema (cagrilintide + semaglutide) reached −20.4% at 68 weeks — still not approved anywhere.
Read the breakdown → Tirzepatide · NEJM 2021SURPASS-2
Tirzepatide vs semaglutide in type 2 diabetes — superior A1c and weight reduction on metformin.
Read the breakdown → Semaglutide · Lancet 2021STEP 2
Semaglutide 2.4 mg for weight in people with type 2 diabetes — the harder-to-move population.
Read the breakdown → Semaglutide · JAMA 2021STEP 4
The withdrawal trial: stopping semaglutide reverses the loss — why obesity is treated long-term.
Read the breakdown → Cardiovascular · NEJM 2016SUSTAIN-6
Semaglutide's cardiovascular-outcomes trial in type 2 diabetes — the diabetes counterpart to SELECT.
Read the breakdown → Tirzepatide · NEJM 2024SURMOUNT-OSA
Tirzepatide cut the apnea-hypopnea index in obstructive sleep apnea — basis for the OSA indication.
Read the breakdown →How the drugs work: mechanisms
The receptors and pathways every drug guide refers back to — what they are, what activating them does, and why the newer dual and triple agonists were designed the way they are.
The GLP-1 receptor
Where it sits, what activation does to insulin, appetite and gastric emptying, and why native GLP-1 fails as a drug.
Read the explainer → ReceptorThe GIP receptor
Why adding GIP agonism to GLP-1 (tirzepatide) may improve weight and glucose outcomes.
Read the explainer → ReceptorThe glucagon receptor
How the glucagon arm of triple agonists like retatrutide raises energy expenditure.
Read the explainer → PathwayThe amylin pathway
The satiety hormone behind pramlintide and cagrilintide, and why it complements GLP-1.
Read the explainer → ConceptThe incretin effect
Why gut hormones amplify insulin after meals, and how incretin drugs exploit it.
Read the explainer →Conditions these drugs treat
The diseases behind the prescriptions — what they are, and what the trials actually showed for each.
Obesity
Why obesity is a chronic disease of appetite regulation, not willpower — and what that means for treatment.
Read the overview → ConditionType 2 diabetes
How incretin drugs improve glucose and weight, and the cardiovascular-outcome evidence.
Read the overview → ConditionMASH (fatty liver)
The liver disease linked to obesity, and the semaglutide and retatrutide liver-fat data.
Read the overview → ConditionObstructive sleep apnea
How weight loss reduces sleep apnea, and the tirzepatide SURMOUNT-OSA result.
Read the overview →Research glossary
The terms that decide what a trial number actually means — defined in plain English so you can read the studies, not just the headlines.
Estimand
Why the same trial reports two different weight-loss percentages — treatment-policy vs trial-product.
Read the definition → TermPhase 2 vs phase 3
What each phase tests, and why phase 2 numbers routinely shrink in phase 3.
Read the definition → TermResponder rate
Why the % reaching ≥5/10/15/20% loss matters more than the average for an individual.
Read the definition → TermNumber needed to treat
How to read NNT, the clearest way to judge how much a treatment actually helps.
Read the definition → Term503A compounding
What pharmacy compounding is, and why the FDA flagged several research peptides.
Read the definition → Term"Research use only"
The labeling loophole grey-market peptide sellers use — and the risks it hides.
Read the definition →Frequently asked questions
Does PepMate recommend or prescribe peptides?
No. PepMate is a tracking and reminder app, and these research pages are educational summaries of published literature. Nothing here diagnoses, prescribes, recommends a peptide, or provides dosing. Decisions about any medication belong to you and your licensed clinician.
Where do the facts in these articles come from?
Every article cites peer-reviewed studies indexed on PubMed, plus regulator records where approval status matters. Each page ends with a numbered source list linking directly to the original abstracts so you can check any claim yourself.
Which peptides actually have strong human evidence?
The GLP-1 class has by far the strongest human trial base: semaglutide, tirzepatide and liraglutide all have large randomized phase 3 programs. Retatrutide and cagrilintide are investigational with phase 2 or phase 3 data. Repair and longevity peptides such as BPC-157, TB-500, epitalon and MOTS-c rest largely on animal and cell research, with little or no controlled human efficacy data.
Are these guides updated?
Yes. Each article carries a last-updated date and is revised when major trial results, approvals, or regulatory changes land — the peptide and GLP-1 field moves quickly, and outdated approval status is the most common error on peptide sites.
Looking for shorter answers instead? The Peptide Q&A covers 62 quick questions, each with its own PubMed source, and mirrors the Learn tab inside the app.
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