The peptide reference that sells nothing.
350 peptides, each with an evidence grade and its sources. 3853 citations, 26 free tools and a dated regulatory tracker.
What changed, and what comes next
FDA's compounding committee backed six of seven peptides (BPC-157 8–6, KPV 8–6, TB-500 8–6, MOTS-c 7–5, Semax 8–5, Epitalon 7–4 or 7–5) and rejected Emideltide (DSIP) 6–7. FDA has not acted on the votes.
The votes and FDA's briefing →Compounded GLP-1s: FDA proposes not to put Semaglutide, Tirzepatide or Liraglutide on the 503B list. No final determination yet.
What it means for you →5 more peptides await the committee (GHK-Cu (injectable), Melanotan II, Cathelicidin (LL-37), Dihexa, PEG-MGF); no meeting date has been set.
The regulatory tracker →Start with your situation
Eight compounds to start with
Chosen by our editors from the compounds the regulatory tracker and FDA's committee cover most; we have no traffic data to rank by. Grades and statuses come from the encyclopedia.
Every tool, by what it does
Calculators
Reconstitution calculatorPrintable reconstitution chartBlend calculatorCost calculatorHalf-life visualizerSplit-dose simulatorGuides by journey
The Retatrutide Hub
The complete, vendor-neutral guide to the most talked-about peptide in the world — FDA status, the record-setting TRIUMPH trial data, mechanism, dosing, side effects, and how access really works. Continuously updated.
Interactive Tools
Free tools. No sign-up. No vendors.
Calculators, builders, and visualizers designed to replace guesswork with precision.
Reconstitution Calculator
25 peptide presets, visual syringe rendering, precise dosage math. The tool every peptide user needs first.
Protocol Builder
27 protocols across 9 goals with Gantt-style timeline visualization. Build complete dosing schedules in minutes.
Interaction Checker
35+ interaction pairs with conflict alerts and auto-generated daily schedules.
Comparison Tool
Radar chart comparison of up to 3 peptides across twelve metrics.
Half-Life Visualizer
Pharmacokinetic modeling with multi-compound overlay plotting.
Vendor Evaluator
Score any vendor against 20 criteria — COA, HPLC, sterility, and more.
Cost Calculator
Cost-per-protocol breakdown with shopping list generation.
Mixing Guide
5 sub-guides with interactive body map for injection sites.
Reference · 350 Peptides
Every peptide,
one reference.
Mechanism, dosing, evidence level, and sourced references for every peptide with published research — from FDA-approved compounds to clinical-trial candidates.
Latest Research
Articles & guides
How GLP-1 Drugs Interact With Common Prescriptions: A Clinical Guide (2026)
Semaglutide, tirzepatide, and other GLP-1 agonists interact with over 30 common prescription medications. A detailed reference covering mechanism, severity, and clinical management.
Read the full guideIndustry news
FDA action, trial readouts, and peptide pipeline developments — by the Grey Peptides News Desk.
REIMAGINE 5: CagriSema vs Tirzepatide
Novo Nordisk reports that CagriSema beat tirzepatide 5 mg on weight loss in people with type 2 diabetes, 12.4% against 9.1% over 60 weeks, with similar HbA1c falls. The results are the company's and not yet published.
Vosoritide in Hypochondroplasia: Phase 3 Growth Result
In a 52-week phase 3 trial in 81 children with hypochondroplasia, vosoritide raised yearly growth by 2.33 cm more than placebo. Vosoritide is approved for achondroplasia, not for hypochondroplasia.
Saxenda to Be Discontinued; Rybelsus Tablets Replaced
Two Novo Nordisk GLP-1 products are leaving the US market according to FDA notices: Saxenda (liraglutide for weight) by January 2027, and the original Rybelsus tablets, which are being replaced by Ozempic tablets.
EloraTZP: 23.3% Weight Loss in Type 2 Diabetes
In 367 adults with type 2 diabetes, the top EloraTZP dose cut weight 23.3% and HbA1c 2.9 points at 48 weeks, against 14.8% and 2.4 on tirzepatide 15 mg. Up to 27% stopped for side effects.
Petrelintide's Paper: Weight Loss Levelled Off Above 5 mg
The ZUPREME-1 paper puts petrelintide's 28-week weight loss at 7.9% to 9.8% against 1.7% on placebo, with doses above 5 mg adding nothing. Other peptide data from EASD 2026 came from Hengrui, Kailera and AbbVie.
Rusfertide Approved: The First Hepcidin Mimetic for Polycythemia Vera
FDA approved rusfertide, sold as Mimrylo, for adults with polycythemia vera on August 28. It is a weekly injected peptide that copies the iron-regulating hormone hepcidin, and in its phase 3 trial it spared far more patients from blood removal than placebo did.