CT-388
InvestigationalAlso known as: RG-6912
A dual GLP-1/GIP receptor agonist acquired by Roche through the $2.7 billion Carmot Therapeutics acquisition in 2024. Phase 1b results showed 18.8% placebo-adjusted weight loss at 24 weeks, positioning it as a competitive obesity therapeutic with a mechanism similar to tirzepatide.
Research Statistics
Phase 2 GLP-1/GIP dual agonist; established GLP-1 receptor mechanism but limited geography.
Research Dossier
Overview
What is CT-388 and what does the research say?
Mechanism of Action
CT-388 is a dual GLP-1/GIP receptor agonist currently in Phase 2 clinical development. Its mechanism is well-characterized based on the established biology of incretin hormones.
How It Works (Simplified)
CT-388 activates two hormone receptors simultaneously to reduce appetite and improve metabolism:
Signals fullness to the brain, slows stomach emptying, and enhances glucose-dependent insulin release from the pancreas.
Synergizes with GLP-1 for enhanced insulin secretion and directly improves fat cell function and lipid metabolism.
Dual receptor activation creates stronger satiety signals than single-receptor drugs, leading to reduced food intake.
Improves insulin sensitivity, reduces blood glucose levels, and may improve lipid profiles through multiple pathways.
Scientific Pathways
GLP-1 Receptor Pathway (Appetite & Glucose)
CT-388 → GLP-1R activation → Hypothalamus POMC/CART ↑ → Reduced appetite
→ Pancreatic β-cells → Glucose-dependent insulin ↑
→ GI tract → Delayed gastric emptyingGIP Receptor Pathway (Metabolic Enhancement)
CT-388 → GIPR activation → Pancreatic β-cells → Synergistic insulin secretion
→ Adipose tissue → Improved lipid metabolism
→ Brain → Enhanced satiety signalingKey Research: Willard FS et al. (2020) established the mechanistic basis for GLP-1/GIP dual agonism. PMID:32956065
Important Limitations
- CT-388 is investigational and not yet FDA approved
- Phase 1b data only; longer-term efficacy and safety data pending
- Specific receptor binding affinities not publicly disclosed
- Head-to-head comparisons with tirzepatide not yet available
- Long-term cardiovascular outcomes data not yet established
Evidence-Chained Benefits
Evidence-Chained Benefits
Research findings linked to mechanisms and clinical outcomes
What to Expect
Timeline based on observations from published studies. Individual responses may vary.
Based on Phase 1b data: Initial GI adaptation period with potential nausea, decreased appetite. Early weight loss begins during dose escalation phase. Glucose improvements may be seen in diabetic patients.
Continued weight loss as dose escalation proceeds. GI side effects typically diminish. Phase 1b showed dose-response relationship across treatment arms with ongoing weight reduction.
Phase 1b demonstrated 18.8% placebo-adjusted weight loss by 24 weeks. Weight loss trajectory suggested no plateau at this timepoint, indicating continued efficacy expected with longer treatment.
Based on tirzepatide data, continued weight loss expected through 52-72 weeks. Maintenance of weight loss requires ongoing treatment. Long-term CT-388 data pending Phase 2/3 results.
Research-Based Observations
This timeline reflects observations from published clinical and preclinical studies. Individual responses may vary significantly. This is not a guarantee of effects or a dosing schedule. Consult qualified healthcare providers for personalized guidance.
Quality Checklist
Visual indicators to help evaluate CT-388 product quality
Good Signs (6 indicators)
Warning Signs (5 indicators)
Bad Signs (6 indicators)
For Research Evaluation Only
These quality indicators are general guidelines based on typical peptide characteristics. Professional laboratory testing (HPLC, mass spectrometry) provides definitive quality verification. This checklist is for initial visual evaluation only.
Peptide Interactions
Known and theoretical interactions when combining CT-388 with other peptides. Based on published research and mechanistic considerations.
Tesamorelin
CompatibleDifferent mechanisms (incretin vs GHRH). No known contraindications. Both target metabolic improvements through distinct pathways.
BPC-157
CautionBoth affect GI function. CT-388 slows gastric emptying significantly while BPC-157 has gastroprotective effects. Unclear if effects interact; monitor GI symptoms if combined.
Tirzepatide
AvoidBoth are dual GLP-1/GIP receptor agonists with overlapping mechanisms. Combining would duplicate effects and increase risk of severe GI adverse events. No clinical rationale for combination.
Semaglutide
AvoidCT-388 already activates GLP-1 receptors. Adding a GLP-1-only agonist would provide no additional benefit while increasing adverse event risk.
Survodutide
AvoidOverlapping GLP-1 receptor activation. Combining dual/triple agonists has no clinical rationale and would compound GI side effects.
Research Note: Interaction data is based on published literature, mechanistic understanding, and theoretical considerations. Most peptide combinations lack direct clinical study. This information is for educational purposes only and does not constitute medical advice. Always consult qualified healthcare providers.
References
Key Studies Cited
Full reference list available on request. All citations link to PubMed for verification.
Methodology Note
This dossier synthesizes available evidence from peer-reviewed literature, regulatory documents, and clinical trial registries. Evidence strength ratings follow a modified GRADE approach.
For complete methodology details, see our Methodology page.
Important Disclaimer
This dossier is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before making health decisions.
Get Research Alerts
New dossiers and major study summaries delivered to your inbox. Evidence-graded, citation-backed research you can trust.
No spam. Unsubscribe anytime.
Compare CT-388
Related Peptides
5-Amino-1MQ
5-Amino-1-Methylquinolinium, NNMT Inhibitor
A small molecule NNMT inhibitor studied for metabolic effects in animal models. No human clinical trials have been conducted. Increases NAD+ levels in adipose tissue in preclinical studies.
Amycretin
NNC0487-0111, Oral Amycretin, Subcutaneous Amycretin
A novel single-molecule dual GLP-1/amylin receptor agonist developed by Novo Nordisk. Unlike CagriSema (a fixed-dose combination), amycretin is a unified peptide that activates both pathways. Phase 1 trials showed superior weight loss signals versus semaglutide, with both oral and subcutaneous formulations in development.
AOD-9604
Anti-Obesity Drug 9604, Tyr-hGH Fragment 177-191, hGH Fragment 176-191
A modified fragment of human growth hormone (amino acids 176-191 with N-terminal tyrosine) studied for fat loss. Clinical development discontinued after Phase 2b/3 trials failed to show efficacy in 536 subjects. Now prohibited by WADA and excluded from FDA compounding.
Cagrilintide
AM833, NN9838, ZP8396
A long-acting amylin analog developed by Novo Nordisk for weight management. Currently in Phase 3 trials as CagriSema (combination with semaglutide). Phase 2 data shows up to 22-25% weight loss when combined with semaglutide, potentially exceeding tirzepatide efficacy.
CagriSema
Cagrilintide-Semaglutide, NNC0174-0833
A fixed-dose combination of cagrilintide (amylin analog) and semaglutide (GLP-1 agonist) for chronic weight management. Phase 3 REDEFINE trials demonstrate 20-23% weight loss at 68 weeks. NDA submitted to FDA December 2025. First GLP-1/amylin combination therapy.
Liraglutide
Victoza, Saxenda, NN2211
The first long-acting GLP-1 receptor agonist, FDA-approved for type 2 diabetes (Victoza, 2010) and chronic weight management (Saxenda, 2014). Pioneered the therapeutic class with proven cardiovascular benefits in the landmark LEADER trial.