Enicepatide vs Tirzepatide (2026): Signal-Biased vs Imbalanced Dual GLP-1/GIP Agonism
Enicepatide vs tirzepatide: signal-biased vs GIP-favoring dual agonism, with 22.5% Phase 2 and 20.9% SURMOUNT-1 weight data. See how the two compare today.
Research reference only. The information in this article is a summary of peer-reviewed scientific literature. It does not constitute medical advice and is not intended to guide human use. See our full disclaimer.
Enicepatide vs tirzepatide is a comparison between two once-weekly dual GLP-1/GIP receptor agonists that differ in how they engage the same pair of receptors: enicepatide (CT-388, RO7795068) is engineered for cAMP signal bias with minimal receptor internalization, while tirzepatide is an imbalanced co-agonist that favors the GIP receptor. This article summarizes the published and publicly reported research on both compounds, including the Phase 1 enicepatide paper (PMID 41319798) and the SURMOUNT-1 tirzepatide trial (PMID 35658024).
Research reference only. All information on this page is a summary of peer-reviewed scientific literature and does not constitute medical advice. See individual library profiles for full compound data.
Quick Answer: Both enicepatide and tirzepatide are once-weekly dual GLP-1/GIP receptor agonists, but enicepatide is signal-biased toward cAMP with reduced receptor internalization, whereas tirzepatide is an approved, GIP-favoring co-agonist. Reported Phase 2 enicepatide data showed 22.5% placebo-adjusted weight loss at 48 weeks, while SURMOUNT-1 reported a 20.9% mean reduction with tirzepatide at 72 weeks; the two figures come from different trials and are not head-to-head.
TL;DR:
- Both compounds activate the GLP-1 and GIP receptors and are dosed once weekly in clinical studies.
- Enicepatide uses signal bias (cAMP) and low receptor internalization; tirzepatide is an imbalanced, GIP-favoring co-agonist.
- Tirzepatide has Phase 3 evidence and regulatory approval; enicepatide remains investigational in Phase 2.
- Cross-trial weight-loss figures differ in duration, population, and endpoint definition and cannot be ranked directly.
- No head-to-head trial of enicepatide and tirzepatide has been published.
Comparison at a glance
| Feature | Enicepatide (CT-388) | Tirzepatide |
|---|---|---|
| Developer | Carmot Therapeutics, advanced by Roche/Genentech | Eli Lilly |
| Receptor targets | GLP-1R and GIPR | GLP-1R and GIPR |
| Signaling profile | cAMP signal-biased, minimal internalization | Imbalanced, GIPR-favoring |
| Development stage | Phase 2 (investigational) | Approved; Phase 3 evidence |
| Reported weight change | 22.5% placebo-adjusted at 48 weeks (Phase 2, 24 mg, topline) | 20.9% mean change at 72 weeks (SURMOUNT-1, 15 mg) |
| Dosing interval in trials | Once weekly | Once weekly |
| Key citation | PMID 41319798 (Phase 1) | PMID 35658024 (SURMOUNT-1) |
Enicepatide: mechanism and evidence base
Enicepatide is a unimolecular dual agonist at the GLP-1 receptor and the GIP receptor. Its design differs from earlier incretin analogues in that it is biased toward cAMP signaling and engineered to minimize receptor internalization at both receptors. The rationale published by the developers is that reduced internalization may sustain signaling over time compared with native ligands. The compound is profiled in the enicepatide library entry.
The principal peer-reviewed source is a Phase 1 study in participants with overweight or obesity (PMID 41319798; NCT04838405). In single ascending doses of 0.5 to 7.5 mg and four once-weekly doses of 5 to 12 mg, the compound was generally well tolerated, with a safety profile consistent with other incretin-based agents. Mean bodyweight change from baseline to day 29 ranged from -4.7% to -8.0%, compared with -0.5% on placebo. In preclinical models, the same publication reported improved glycemic control, reduced bodyweight, appetite suppression, and improved steatohepatitis pathology.
A Phase 2 obesity trial (NCT06525935) was reported by Roche as a topline readout in January 2026 and presented at ADA 2026. The reported figure was 22.5% placebo-adjusted weight loss at 48 weeks at the 24 mg dose, with 54% of participants reaching a BMI under 30 kg/m2 versus 13% on placebo and no plateau observed. A full peer-reviewed publication of these Phase 2 data was not available at the time of writing, so the figures should be treated as company-reported topline results. A Phase 2 study in type 2 diabetes (NCT06628362) and a planned combination study with petrelintide (NCT07589686) are also registered.
Tirzepatide: mechanism and evidence base
Tirzepatide is a 39-amino-acid peptide that acts as a dual GIP and GLP-1 receptor agonist. Pharmacology work has described it as an imbalanced co-agonist, with stronger activity at the GIP receptor than at the GLP-1 receptor, and has examined how this affects receptor trafficking. Its mechanism is covered in more depth in the tirzepatide mechanism of action overview and the tirzepatide library profile.
The pivotal obesity evidence is SURMOUNT-1 (PMID 35658024), a randomized, placebo-controlled trial in adults with obesity without diabetes. In that trial, the mean percentage change in body weight at 72 weeks was approximately 15.0% at 5 mg, 19.5% at 10 mg, and 20.9% at 15 mg, versus 3.1% with placebo. Real-world observational data have since added context on persistence. A single-center cohort from the United Arab Emirates (PMID 42029986) reported median weight reductions of 8.1% in participants treated for one year or less and 22.6% in those treated for longer than one year.
Tirzepatide is the more mature dataset by a wide margin. It has multiple Phase 3 programs, post-marketing observational studies, and an established regulatory record, whereas enicepatide has a single published Phase 1 paper and topline Phase 2 communications.
How signal bias differs from imbalanced co-agonism
Both strategies attempt to improve on single-receptor GLP-1 agonism such as semaglutide, but they address different design questions. Imbalanced co-agonism asks how much GIP receptor activity should accompany GLP-1 receptor activity. Signal bias asks which intracellular pathway a ligand preferentially activates once bound, and whether less internalization changes how long a receptor keeps signaling.
Published discussion of both approaches remains partly mechanistic. Whether cAMP bias and reduced internalization translate into durable clinical differences has not been tested in a randomized comparison. For that reason, the weight-loss numbers above should be read as a description of each program, not as a ranking.
Why cross-trial comparisons need caution
The 22.5% placebo-adjusted enicepatide figure and the 20.9% unadjusted tirzepatide figure are not equivalent measurements. Placebo-adjusted values subtract the placebo effect, while the SURMOUNT-1 figure quoted here is the mean change from baseline. Trial duration (48 versus 72 weeks), dose escalation schedules, participant characteristics, and analysis populations also differ. SURMOUNT-1 placebo-adjusted weight loss at 15 mg was roughly 17.8 percentage points by subtraction, which illustrates how much the framing changes the apparent magnitude.
Researchers comparing the two programs typically align endpoints first, then look at the dose-response curves, discontinuation rates, and gastrointestinal event profiles reported for each. The clinical trial tracker lists registered studies for investigational incretin compounds, and the half-life chart provides pharmacokinetic reference values for context on dosing intervals.
Position within the broader dual-agonist field
Enicepatide and tirzepatide sit alongside several other incretin programs. The mazdutide vs tirzepatide comparison covers a GLP-1/glucagon dual agonist against the GLP-1/GIP reference, and the VK2735 vs semaglutide comparison covers a related GLP-1/GIP candidate. Triple agonism is represented by retatrutide, which adds glucagon receptor activity.
Regulatory status
Tirzepatide is approved by regulators in multiple jurisdictions for specified indications, and its status is documented in its library profile. Enicepatide has no regulatory approval as of the most recent library update and is in Phase 2 clinical development for obesity and type 2 diabetes. It is an investigational peptide and is not eligible for 503A compounding.
Cited studies
- PMID 41319798: "Effects of CT-388, a Once-Weekly Signaling-Biased Dual GLP-1/GIP Receptor Agonist, on Weight Loss and Glycemic Control in Preclinical Models and Participants With Obesity." (Molecular Metabolism, 2025). https://doi.org/10.1016/j.molmet.2025.102291
- PMID 35658024: "Tirzepatide Once Weekly for the Treatment of Obesity" (New England Journal of Medicine, 2022). https://doi.org/10.1056/NEJMoa2206038
- PMID 42029986: "Persistence-Dependent Effectiveness of Tirzepatide on the Cardio-Metabolic-Kidney Syndrome Outcomes in Obesity: Real-World Evidence from the United Arab Emirates." (Diabetes Therapy, 2026). https://doi.org/10.1007/s13300-026-01868-2
Frequently asked questions
Q: What is the difference between enicepatide and tirzepatide?
A: Both are once-weekly dual GLP-1/GIP receptor agonists. Enicepatide is engineered for cAMP signal bias with minimal receptor internalization, while tirzepatide is an imbalanced co-agonist that favors the GIP receptor.
Q: Is enicepatide the same as CT-388?
A: Yes. Enicepatide is the nonproprietary name for CT-388, also coded RO7795068. It was developed by Carmot Therapeutics and advanced by Roche/Genentech after Roche's 2023 acquisition of Carmot.
Q: How much weight loss did enicepatide show in Phase 2?
A: Roche reported 22.5% placebo-adjusted weight loss at 48 weeks at the 24 mg dose in topline Phase 2 results. These figures had not yet appeared in a full peer-reviewed paper at the time of writing.
Q: Has enicepatide been compared directly with tirzepatide?
A: No head-to-head trial has been published. Any comparison between the two relies on separate trials with different durations, populations, and endpoint definitions.
Q: Is enicepatide approved?
A: No. Enicepatide is investigational and in Phase 2 development, whereas tirzepatide has regulatory approval in several jurisdictions.
See also:
- Tirzepatide vs semaglutide: dual agonist comparison: the reference comparison for GLP-1/GIP co-agonism against GLP-1 alone
- Mazdutide vs tirzepatide: a GLP-1/glucagon dual agonist against the GLP-1/GIP reference
- VK2735 vs semaglutide: another investigational GLP-1/GIP candidate in Phase 3
For laboratory research purposes only. Not for human or animal consumption. Compounds described are not approved by the FDA for human or veterinary use unless explicitly stated.