How to reconstitute Retatrutide: mixing and storage

An experimental weekly injection with phase 3 weight-loss results.

Also called: LY3437943, LY-3437943, Reta.

GLP-1 / GIP / glucagon agonists · GIP, GLP-1 and glucagon receptor triple agonist.

Comes as: Freeze-dried powder in vials labelled for multiple doses; community reports, with contents and sterility unverified, Unapproved pens seized by regulators.

Mixed with: Users report bacteriostatic water for injection. There are no approved mixing instructions; this water does not sterilize contaminated powder..

Common vial sizes: 5, 10, 16, 20, 30 mg. Common water amounts: 0.5, 1, 2 mL.

  • Reported mixes include 10 mg/1 mL, 20 mg/2 mL and 16 mg/2 mL. Vial contents and resulting concentrations were not checked.
  • Syringe units measure volume. With U-100 syringes, 100 units is 1 mL; the dose in milligrams depends on the actual concentration.
  • Identity, amount, sterility and bacterial-toxin tests answer different questions. A clear liquid or a purity percentage alone cannot confirm injection quality.
  • Trial mixtures, storage and devices were controlled. Those results do not establish how an unknown vial should be mixed or stored.

Before mixing: Users report refrigeration or freezing dry powder, sometimes around −20°C. Shelf life and tolerance of shipping temperatures are unknown for unverified vials.

After mixing: Users report 2–8°C refrigeration; shelf life in bacteriostatic water is unknown. FDA’s general 28-day limit after first use of sterile vials does not establish these products’ stability or sterility.

Related to Retatrutide

Sources

Sources checked: 2026-10-22.

Information only, not medical advice. Peptifacts does not sell anything and does not link to sellers.