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
12 tools no other peptide site has
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 · 296 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.
The FDA Comment Window on Compounded GLP-1s Closes July 30 — Not June 29
A two-page notice quietly moved the deadline thirty days and most coverage never updated. The docket is open until 11:59 p.m. ET on July 30.
FDA Staff Propose Rejecting All Seven Peptides Before Next Week's Committee
Briefing documents for the July 23-24 PCAC meeting show staff proposing against all fourteen substances, including BPC-157, TB-500 and semax.
ADA 2026 Preview: The Incretin Readouts to Watch in New Orleans
The ADA's 86th Scientific Sessions open June 5 in New Orleans. Retatrutide, CagriSema, survodutide, and oral orforglipron headline a packed incretin agenda.
TRIUMPH-1: Retatrutide Posts Bariatric-Level Weight Loss in Phase 3
On May 21, Eli Lilly reported topline TRIUMPH-1 results: retatrutide drove up to 28.3% mean weight loss at 80 weeks — the largest pharmacological obesity readout to date.
A Single Peptide That Hits Five Receptors: The Quintuple Agonist
A Nature paper describes GLP-1-GIP-lanifibranor, one molecule that activates five metabolic receptors at once. It corrects obesity and diabetes in mice — emphasis on mice.
Ozempic Pill Reaches US Pharmacies: First Oral Peptide GLP-1 for Type 2 Diabetes
Starting May 4, Novo Nordisk's Ozempic tablets reached US pharmacies — the first oral peptide GLP-1 approved for type 2 diabetes, with cardiovascular risk reduction on label.