# CT-388 Dosing Guide: Weekly Dual GLP-1/GIP Up to 24 mg
> Note: PeptIQ is not a medical provider. CT-388 is investigational. Educational dosing literacy only.
CT-388 is Roche/Genentech's investigational dual GLP-1/GIP receptor agonist — same broad class story as tirzepatide, with a Phase 2 obesity program that put 24 mg once weekly on the map.
Quick Answer: CT-388 Dosage
| Design element | Public Phase 2 detail (CT388-103) |
|---|---|
| Cadence | Once-weekly subcutaneous |
| Target dose cohorts | 4, 8, 12, 16, or 24 mg (different up-titration schemes) |
| Highest dose tested | 24 mg |
| Duration | 48 weeks primary window |
| Population | Obesity / overweight + comorbidity, without type 2 diabetes (Phase 2 obesity study) |
Results People Cite
At the 24 mg dose / week 48 (public Roche/Genentech topline):
- Placebo-adjusted weight loss about 22.5% (efficacy estimand)
- About 18.3% placebo-adjusted on the treatment-regimen estimand
- High responder rates (≥5%, ≥10%, ≥20%, even ≥30% buckets reported)
- ~54% achieved BMI <30 ("obesity resolution") vs ~13% placebo in public summaries
- Among baseline prediabetes, a large majority normalized glucose vs few on placebo
- GI AEs mostly mild–moderate; discontinuation due to AEs relatively low in sponsor communications
Earlier Phase 1b work reported ~18.8% placebo-adjusted loss over 24 weeks — useful context that the dual-agonist signal showed up early.
How CT-388 Compares in the Dual-Agonist Lane
| Drug | Pathway | Public weekly top anchors |
|---|---|---|
| Tirzepatide | GLP-1 + GIP | Approved labeled ladder |
| CT-388 | GLP-1 + GIP (biased signaling design per Roche) | Phase 2 up to 24 mg |
| Survodutide | GLP-1 + glucagon | Phase 3 up to 3.6 / 6.0 mg |
| Retatrutide | GLP-1 + GIP + glucagon | Triple-agonist program |
Milligrams are not interchangeable.
Stacking Note (Petrelintide)
Roche has also signaled Phase 2 interest in combining petrelintide (amylin analog) with CT-388. That is the amylin + dual-incretin stack thesis — not a DIY syringe protocol.
What to Track
- Weekly dose step toward target (4→24 mg ladder literacy)
- GI scores after titration bumps
- Protein + lifting
- Average weight / waist
- Glucose status if prediabetic
FAQ
Q: What is the CT-388 dose for weight loss?
A: Phase 2 explored weekly targets of 4–24 mg. Highest publicly highlighted efficacy sat at 24 mg.
Q: Is CT-388 better than tirzepatide?
A: No head-to-head verdict from identical Phase 3 packages in this summary. Compare estimands and wait for mature data.
Q: Is CT-388 approved?
A: Investigational as of this writing — verify current regulatory status.
Bottom Line
CT-388 dosing in public science means once-weekly titration across 4–24 mg, with a standout Phase 2 placebo-adjusted loss near 22.5% at 24 mg / 48 weeks on the efficacy estimand. Learn the ladder; refuse gray-market milligram cosplay.
Download PeptIQ to log weekly dual-agonist titration cleanly.
Educational content only. Not medical advice.
