For Laboratory Research Use Only. Not for human or veterinary use.

Available Powder Sizes

Specifications

• Synonyms: LY3437943, “GLP-3” triple-agonist (colloquial)
• Purity: ≥99% (HPLC/MS)
• Appearance: White lyophilized powder (collapsed/fragmented cake is normal)
• Molecular Formula: C₂₂₁H₃₄₂N₄₆O₆₈
• Molecular Weight: ≈ 4731.33 g/mol
• Preparation: No mannitol, buffers, or fillers

Storage & Stability

• Lyophilized: ≤ −20 °C; protect from moisture/light.
• After reconstitution: 2–8 °C; minimize freeze–thaw cycles; protect from light.

Retatrutide: Research Overview

Retatrutide (LY3437943) is a laboratory peptide used to investigate multi-receptor metabolic signaling in model systems. Because it is a large, sequence-defined molecule, the usefulness of any given lot depends on precise synthesis, purification, and storage. This powder format is intended for labs that prefer lot-level control—aliquoting, preparing custom concentrations, and running method-consistent assays across time.

Our powder is filler-free. Some suppliers add bulking agents (e.g., mannitol, trehalose) to create a taller cake. We intentionally avoid bulking agents so the solids correspond predominantly to the target peptide, which simplifies mass-based calculations during method development. Visual cake height therefore varies by charge volume and lyophilization profile and should not be interpreted as “under-filled” or “low purity.”

Mannitol-Free vs. Bulking-Agent Preparations

Purity & Identity: How to Read the COA

Each lot ships with a batch-matched Certificate of Analysis (COA). We pair orthogonal methods:

• RP-HPLC (area %): Target main-peak area is typically ≥99%. Verify column type, gradient, and detection wavelength to align your in-house method.
• Mass spectrometry: Confirms molecular mass (monoisotopic/average) and screens for truncations/modifications.
• Ancillary tests (if applicable): Residual solvents or water (KF), counter-ion content, and bioburden/endotoxin for certain research contexts.

Interpreting HPLC: a dominant main peak with minimal shoulders and clean baseline suggests high chemical purity. If you compare across vendors, note that excipients can contribute extra peaks even at high peptide purity—another reason this product is prepared without bulking agents.

Lyophilization & Visual Appearance

Without a bulking lattice, filler-free cakes often appear as thin films, glassy sheets, or fragmented chunks after transit. Load volume (e.g., 0.3–0.5 mL), freezing rate, and primary-drying profile drive morphology. These features do not correlate with purity or mass; analytics do.

Typical Lab Workflow (Conceptual)

1. Plan concentration. Choose a convenient stock concentration for your assays and pipetting math (e.g., powers of 10).
2. Wetting & dissolve. Add diluent along the vial wall; allow the film to wet fully before swirling. Avoid frothing.
3. Aliquot. Split into sub-vials to minimize freeze–thaw cycles. Label with lot, concentration, and date.
4. Store. Keep cold and protected from light per your SOP. Handle briefly at ambient humidity to limit moisture uptake.

Note: We provide no dosing, administration, or in-vivo guidance. All information here supports general laboratory handling concepts only.

Why Labs Choose Powder Over Vials

• Method development: Powder enables micro-adjustments to concentration and buffer systems during optimization.
• Economics: Larger lots reduce cost per mg and simplify longitudinal studies using a single batch.
• Traceability: A single powder lot with documented aliquoting often yields cleaner audit trails than multiple vial lots.

Packaging, Shipping & Chain of Custody

• Primary container: Type I borosilicate, compatible closure, tamper evidence.
• Shipment: Insulated packaging with cold-chain materials appropriate to ambient conditions.
• Documentation: Lot-matched COA with QR/URL access; order history maintains traceability for audits.

FAQ