On September 15, 2026, Syntis Bio reported 28-day multiple-ascending-dose (MAD) results from the Phase 1/1b SYNTIETY-1 trial of oral SYNT-101 in overweight or obese adults. The company said the once-daily tablet transiently lined the duodenum, raised endogenous GLP-1 and PYY 2- to 5-fold, lowered ghrelin, and produced more weight loss than placebo in each of three dose cohorts.
That is a company Phase 1 MAD topline. It is not a peptide drug. It is not FDA approval. The release did not publish a weight-loss percent.
ClinicalTrialsArena recapped the same MAD facts on September 16, 2026, and added no efficacy percent. NCT07307274 is the matching 55-subject Phase 1 SAD/MAD registry record. This article does not treat a registry status flip as news.
This is the 8:07 Industry News slot for 16 September 2026. It is not a Research Roundup.
What happened on September 15
The company release covers the MAD portion of SYNTIETY-1. Design: randomized, double-blind, placebo-controlled. Population: 23 overweight or obese adults. Duration: 28 days. Doses: three ascending cohorts from 857 mg to 2,571 mg, described as one to three tablets.
Safety, as the company reported it. SYNT-101 was well tolerated at all MAD doses. No discontinuations. No dose reductions. Gastrointestinal adverse events occurred at a similar rate to placebo.
Exploratory pharmacodynamics, as the company reported them. Endogenous GLP-1 and PYY rose 2- to 5-fold. Ghrelin decreased. Syntis called that pattern concordant with a gastric-bypass-like multi-hormone signature.
Weight, as the company reported it. SYNT-101 participants lost more weight than placebo in each of the three cohorts. The company said that loss was "comparable to weight loss observed with GLP-1 therapies after the same treatment duration." The press release did not publish a percent, a kilogram change, or a cohort-level table. This article does not invent one.
ClinicalTrialsArena restates those points.
Syntis said detailed results will be a late-breaking presentation at The Obesity Society's 44th Annual Meeting at ObesityWeek 2026, November 14-17 in Washington, DC. A Phase 2 study is planned for 2027. Those are company timelines.
The MAD readout sits on earlier SAD data announced in July 2026 and a full SYNTIETY-1 program the company describes as 55 subjects. First-patient dosing in March 2026 is background only.
What SYNT-101 is (and is not)
SYNT-101 is an investigational once-daily oral tablet. The company says it transiently blocks nutrient absorption in the proximal small intestine and redirects nutrients distally, which then stimulates the body's own satiety hormones.
The coating is SYNT (SYNthetic Tissue-lining): a mussel-inspired polydopamine lining on catalase-rich tissue such as the duodenum. Syntis says the lining lasts up to about 24 hours and then clears. The company designed the product to avoid systemic circulation. That is a company mechanism claim, not a published pharmacokinetic table in this week's package.
This is not an exogenous GLP-1, GIP, or amylin peptide. It is not semaglutide and not tirzepatide. A research-catalog "GLP-1" vial is not SYNT-101. A COA check can test whether a certificate names a real lab. It cannot turn a listing into this gut-lining tablet.
PYY here is an endogenous hormone measurement, not a PYY research peptide. The MAD highlight list reported GLP-1, PYY, and ghrelin.
What the MAD numbers show
The published package is small and company-owned.
Safety is the strongest line: n=23, 28 days, all three tablet strengths, no dropouts or dose cuts, GI events similar to placebo. That is still Phase 1, not a Phase 3 safety database.
The hormone data are labeled exploratory pharmacodynamics. 2- to 5-fold GLP-1 and PYY is a range, not a dose-response table. The release does not give time points, meal-challenge methods, or confidence intervals.
The weight line is directional. More loss than placebo in each cohort is a company summary. "Comparable to GLP-1 therapies" after 28 days is a company comparison without a cited trial, without a percent, and without a published placebo-adjusted figure. A 28-day Phase 1 MAD is a different design from multi-month incretin programs already covered here, including STEP Young.
David Rosenbaum, Ph.D., Syntis's chief development officer, called the package a de-risking milestone toward Phase 2 and stressed a mechanism "specifically designed to avoid systemic circulation." PeptidePrices reports that quote. It does not adopt it as a finding. Company preclinical language in the same release is rodent data. It is not the 23-person MAD table.
What the registry still says
NCT07307274 is protocol SYNT101-001, sponsor Syntis Bio: a Phase 1 randomized, double-blind, placebo-controlled SAD and MAD study in healthy adults and in healthy adults who are overweight or have obesity.
Queried 16 September 2026 via ClinicalTrials.gov API v2, the record is COMPLETED. Actual enrollment is 55, matching the company's 55-subject Phase 1/1b description. Actual start is 13 January 2026. Actual completion is 14 July 2026. Last update posted 26 August 2026. hasResults is false. The listed site is Veritus Research, Bayswater, Victoria, Australia. The registered primary is safety.
Those fields identify the study. They do not add a weight-loss percent. COMPLETED was already posted in August, before the September 15 topline. This article does not invent a registry status change as news.
What this does not mean
- It is not a peptide drug. SYNT-101 is an oral polydopamine gut lining, not an exogenous GLP-1 peptide.
- A 2- to 5-fold rise in endogenous GLP-1 and PYY is not the same as dosing semaglutide or tirzepatide. Those products circulate as drugs. This candidate is designed to move the body's own hormones after a meal.
- It is not FDA approval, and it is not Phase 3. MAD in 23 people for 28 days is exploratory human dosing.
- "Comparable to GLP-1" is a company phrase. The September 15 release published no weight-loss percent.
- Well tolerated for 28 days is not a long-term safety label. Exploratory pharmacodynamics is not the registry primary. The registry primary is safety.
- ObesityWeek is a meeting date, not a paper. Phase 2 in 2027 is a company plan, not an enrolled pivotal trial.
- A research-vendor GLP-1, PYY, or "gut lining" listing is not SYNT-101.
What to watch
- The ObesityWeek 2026 late-breaker, especially any missing percent, dose-response, and methods.
- A posted NCT07307274 results module. hasResults is still false.
- Whether Phase 2 in 2027 actually starts, and on what endpoint.
FAQs
Is SYNT-101 a peptide or an approved GLP-1 drug?
No. It is an investigational once-daily oral polydopamine gut lining designed to raise the body's own GLP-1, PYY, and related hormones. It is not semaglutide, tirzepatide, or a research-catalog peptide.
Did Syntis publish a weight-loss percent on September 15, 2026?
No. The company said SYNT-101 participants lost more weight than placebo in each MAD cohort and called that loss comparable to GLP-1 therapies after the same duration. The release did not print a percent.
What did the 28-day MAD show?
In 23 overweight or obese adults, three ascending cohorts from 857 mg to 2,571 mg, the company reported tolerability at all doses, no discontinuations or dose reductions, GI adverse events similar to placebo, 2- to 5-fold rises in endogenous GLP-1 and PYY, and a decrease in ghrelin.
Is SYNT-101 FDA-approved for obesity?
No. This is a Phase 1/1b company topline. Phase 2 is planned for 2027. A late-breaker is planned for ObesityWeek 2026. None of that is a marketing approval.
What is NCT07307274?
It is the ClinicalTrials.gov record for SYNTIETY-1 / SYNT101-001. Queried 16 September 2026, it is COMPLETED, actual enrollment 55, last update posted 26 August 2026, no results module. Use it as study identity, not as a new status headline.
What dose was studied?
The MAD used three ascending cohorts from 857 mg to 2,571 mg (one to three tablets) once daily for 28 days. SYNT-101 is not approved. That is not a consumer protocol.
This article is for general informational purposes only and is not medical advice. Talk to a licensed clinician about personal medical decisions. SYNT-101 remains investigational. Nothing here is a dosing protocol or a recommendation to obtain an unapproved product.
Continue your research
- STEP Young semaglutide in children
- Mounjaro (tirzepatide) cardiovascular approval
- Semaglutide prices
- Tirzepatide prices
- COA Authenticity Checker
Sources
- Syntis Bio. Syntis Bio reports Phase 1/1b results demonstrating weight-loss and satiety hormone modulation with oral SYNT-101 in patients with obesity. 15 September 2026
- ClinicalTrialsArena. Syntis Bio announces Phase I/Ib data for SYNT-101 in obesity. 16 September 2026
- ClinicalTrials.gov NCT07307274. A study of SYNT-101 to test safety, tolerability and pharmacodynamics of SYNT-101 in healthy and overweight adults (SYNT101-001)