§ 01 Overview
Overview
Investigational triple agonist (GLP-1, GIP, glucagon) producing the largest weight loss seen in Phase II trials to date.
Phase II complete (NEJM 2023). Phase III (TRIUMPH program) currently enrolling. Not yet FDA-approved.
§ 02 Mechanism
Mechanism of action
Retatrutide activates GLP-1, GIP, and glucagon receptors. The glucagon agonism is hypothesized to increase energy expenditure through hepatic and adipose effects, while the GLP-1/GIP arms drive appetite suppression.
- 0124% mean body weight reduction at 48 weeks (Phase II, 12 mg)
- 02Improvements in hepatic fat and liver enzymes
- 03Potential energy expenditure effect via glucagon arm
§ 03 Dosing
Dosing protocol
Standard Protocol
- Dose Range
- 1 – 12 mg weekly (trial protocol)
- Route
- SubQ
- Frequency
- Weekly
- Cycle
- Phase III titration typically escalates monthly.
§ 04 Evidence
Evidence & research
Phase II complete (NEJM 2023). Phase III (TRIUMPH program) currently enrolling. Not yet FDA-approved.
FDA Status
Investigational. Not approved. Compounding is not legally available.
§ 06 News
In the news
8 articles from the last 12 months · updates hourly
The experimental drug being marketed as the next big thing in weight loss - The Independent
The experimental drug being marketed as the next big thing in weight loss The Independent
The Allure and Risks of Retatrutide: A Weight Loss Revolution? - Devdiscourse
The Allure and Risks of Retatrutide: A Weight Loss Revolution? Devdiscourse
Will retatrutide help me lose weight or look ‘shredded’? - The Conversation
Will retatrutide help me lose weight or look ‘shredded’? The Conversation
What experts say about claims of new weight-loss drug making people fall out of love - CP24
What experts say about claims of new weight-loss drug making people fall out of love CP24
He Tried Dieting, Training, Even Testosterone — But Nothing Touched His Belly Fat. Then Retatrutide Changed - PR Underground
He Tried Dieting, Training, Even Testosterone — But Nothing Touched His Belly Fat. Then Retatrutide Changed PR Underground
Everyone Wants This Unapproved Weight Loss Drug—And Some Have Found a Way to Get It - SELF Magazine
Everyone Wants This Unapproved Weight Loss Drug—And Some Have Found a Way to Get It SELF Magazine
newsGP - TGA issues warning against unapproved peptides - Royal Australian College of General Practitioners (RACGP)
newsGP - TGA issues warning against unapproved peptides Royal Australian College of General Practitioners (RACGP)
Extreme Side Effects Followed Overdose of Unapproved Weight-Loss Drug - MedPage Today
Extreme Side Effects Followed Overdose of Unapproved Weight-Loss Drug MedPage Today
§ 07 Sourcing
Sourcing & supply
Regulatory status
Investigational, no compounding path
Currently in active clinical trials. No compounding pathway. No brand product. The only US channels are RUO vendors that the FDA has targeted with warning letters. Assume any sourcing carries significant regulatory and quality risk.
International · 1
Trident Peptides
1,299+ Trustpilot reviews (5-star). Strongest review base in UK research peptides. No visible ISO/GMP; COAs not posted.
Research-use-only · 6
Swiss Chems
Established SARMs/peptide vendor. FDA warning letter Dec 2024 for GLP-1s. Weaker peptide QC than SARMs QC.
Limitless Life Nootropics
'Only BBB-accredited peptide company' (since 2020). Claims three-lab third-party testing. Broad catalog.
Elite Research USA
High-risk. Finnrick tested 47 samples across 7 products → ratings B to E. Heavy TikTok marketing. No accreditations verified.
Prime Peptides
Uses Janoshik testing. FDA warning letter December 2024 for GLP-1s.
Summit Research
FDA warning letter December 2024 across multiple GLP-1s.
Listings are informational, not endorsement. Verify credentials and flags against FDA and PCAB databases before purchasing. Full directory & how to verify →
§ 09 Safety
Safety & side effects
Side effects
- 01Nausea, GI effects similar to other incretins
- 02Transient heart rate increase
- 03Limited long-term safety data
Contraindications
None specified.
§ 10 References
Selected references
- 01
Retatrutide Phase II — obesity
NEJM 2023