How to Buy Retatrutide
for Research

What is Retatrutide?

Retatrutide (also called Reta or LY3437943) is the most advanced metabolic peptide currently in clinical development. Developed by Eli Lilly, it is the world's first triple GIP/GLP-1/Glucagon receptor agonist — simultaneously targeting three hormonal pathways involved in weight regulation, glucose metabolism, and energy expenditure.

In a landmark Phase 2 trial published in the New England Journal of Medicine (June 2023), Retatrutide produced 24.2% mean body weight reduction at 48 weeks at the highest dose — a result that surpassed every previously studied pharmaceutical agent without surgery, with no plateau observed at trial end.

Purity & COA Verification — The Most Important Factor

The single most critical factor when purchasing any research peptide — and especially Retatrutide — is verified purity with documented evidence. A Certificate of Analysis (COA) is the non-negotiable baseline for any serious research application.

What to Look for in a COA

• HPLC purity percentage: Should show ≥99% purity. Anything below 97% is considered insufficient for high-quality research.
• Mass spectrometry confirmation: Confirms the peptide identity matches the expected molecular formula for Retatrutide (LY3437943).
• Batch number: The COA should reference a specific batch that can be matched to your order.
• Testing date: Recent testing indicates fresh stock, not aged inventory being recycled with old documentation.
• Third-party testing: Ideally from an independent laboratory, not only internal testing from the supplier.

QSC Peptides provides a Certificate of Analysis with every Retatrutide order showing HPLC-verified ≥99% purity. COAs are available for each product and batch on the QSC website.

Domestic vs China Direct — Which to Choose

Retatrutide is available from two sourcing routes through QSC Peptides: domestic warehouse fulfillment or China direct shipment. Understanding the difference is critical for research planning.

Domestic Warehouse (USA, EU, UK, AU, CA)

Domestic fulfillment means QSC ships from physical inventory held in a warehouse located within your country or region. For US researchers, this means USPS or FedEx with standard 2–5 business day delivery. Key advantages:

• No customs exposure or import delays
• Faster delivery timelines
• Reduced risk of package loss or seizure at international borders
• Standard domestic tracking via USPS/FedEx

China Direct

China direct ships from QSC's manufacturing source in Qingdao, China. This is the appropriate choice for:

• Researchers in countries without a local QSC warehouse
• Bulk orders where per-milligram cost is the primary priority
• International researchers comfortable with longer delivery timelines (typically 7–21 business days)

Choosing the Right Vial Size & Kit

QSC Retatrutide is available in two kit configurations and nine concentration options. Here's how to think about the choice:

10-Vial Kits

Best for initial research runs, shorter protocols, or researchers who want to evaluate multiple concentrations across different experiments. Available in 5mg, 10mg, 15mg, 20mg, 30mg, 40mg, 50mg, 60mg, and 100mg per vial.

20-Vial Kits

Better per-vial value for extended research programs. Identical vial concentrations as the 10-vial kits (5mg through 60mg) but with more total peptide at a lower effective cost per milligram. Ideal for ongoing or multi-cohort research.

Retatrutide + Cagrilintide Blend

For researchers studying multi-pathway metabolic interventions, the Reta+Cagrilintide blend provides a four-receptor stack (GIP + GLP-1 + Glucagon + Amylin) in a single convenient vial. Available as a 10mg/10-vial kit at $310.

Retatrutide Pricing — What You Should Expect to Pay

QSC Peptides offers the following pricing for research-grade Retatrutide (all include free shipping and COA):