Retatrutide
Also known as: LY3437943
Overview
Retatrutide is a triple agonist targeting GLP-1, GIP, and glucagon receptors simultaneously. It is one of the most potent weight loss peptides currently in clinical trials, demonstrating superior fat loss outcomes compared to dual agonists like tirzepatide in early phase trials.
How it works
Acts as a triagonist at GLP-1, GIP, and glucagon receptors. GLP-1 agonism reduces appetite and slows gastric emptying. GIP agonism enhances insulin secretion and improves metabolic function. Glucagon agonism increases energy expenditure and promotes lipolysis, making it uniquely effective for fat loss beyond appetite suppression alone.
Primary uses
- Fat loss
- Blood sugar regulation
- Appetite suppression
- Metabolic health
- Energy expenditure
What to expect
Based on reported user experiences and available research, here is a general timeline of effects:
Days 1–14
- Appetite suppression typically begins within the first 1-2 weeks
- Some nausea or digestive adjustment is normal at this stage — take with food
Days 14–42
- Meaningful weight loss is typically visible by week 3-4
- Blood sugar regulation improvements are becoming established
- Energy levels often improve as metabolic health adapts
Days 42–84
- Significant fat mass reduction is measurable at this point
- GLP-1 and glucagon receptor adaptations are well established
- Body composition changes are clearly visible by week 8-10
Days 84–999
- You are in the advanced phase — maximum fat loss efficacy
- Consider dose review with your provider to optimise the next phase
- Monitor lean mass to ensure muscle is being preserved alongside fat loss
Storage and preparation
Store lyophilised powder at -20°C or 4°C away from light. Once reconstituted, store at 4°C and use within 28 days. Do not freeze reconstituted solution.
Reconstitute with bacteriostatic water. Add water slowly down the side of the vial. Gently swirl — do not shake. Standard reconstitution: 2mg vial with 2ml BAC water gives 1mg/ml concentration.
Research
The following studies are available via PubMed:
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