What is TIX100?

The problem TIX100 is aimed at

Roughly half of people who start a GLP-1 stop taking it within a year. Seventy percent stop within two. Whatever the reason, cost, side effects, needle fatigue, most of them find out the same thing afterward: the weight comes back. Our own breakdown of the withdrawal trial data shows people who stop semaglutide regain about two-thirds of their lost weight within a year, and tirzepatide stoppers are not far behind. There is currently no approved drug built specifically to hold the line after a GLP-1 stops.

TIX100 is the first compound with a published result that directly targets that gap. It comes out of the University of Alabama at Birmingham, developed by a startup called TIXiMED and led by endocrinologist Dr. Anath Shalev, whose lab spent close to two decades studying a protein called TXNIP before anyone connected it to weight regain at all.

What is TIX100, and how does it work?

TIX100 is a small-molecule, orally dosed inhibitor of TXNIP, thioredoxin-interacting protein. TXNIP was not discovered as an obesity target. Shalev's lab identified it years earlier as a driver of insulin-producing beta cell death and dysfunction in diabetes, and TIX100 was built to block it for that reason. Earlier mouse work, published before the weight-regain study, found that TIX100 also cut diet-induced fat gain by about 50% and reduced overall weight gain by roughly 15% in mice on a high-fat diet, while protecting against glucose intolerance and reversing elevated glucagon. The weight-regain question came later, once researchers wondered what TIX100 would do to an animal that had already lost weight on a GLP-1 and then stopped.

Because TIX100 never touches the GLP-1 receptor, it works through a mechanism entirely separate from semaglutide, tirzepatide, or any drug covered elsewhere on this site. That is also the pitch: a drug that does not act on GLP-1 should not carry GLP-1's signature nausea and vomiting, and researchers reported exactly that in the animal data.

What happened when mice stopped their GLP-1

The study, published in Diabetes, Obesity and Metabolism in March 2026, ran a straightforward experiment. Mice on a high-fat diet were treated with semaglutide for two weeks, during which they lost more than 13% of their body weight. Semaglutide was then stopped, the same moment of discontinuation that drives the rebound seen in human trials, and the mice were split into two groups.

The control group, given nothing after semaglutide stopped, regained about 14% of their body weight within four weeks, the same fast rebound pattern researchers see in people who stop GLP-1 therapy. Mice given oral TIX100 during that window showed no significant regain at all. Researchers tied the effect to reduced fat mass, lower food intake, and lower circulating leptin, with lean mass fully preserved, meaning the weight held off was fat, not muscle.

Why avoiding the GLP-1 receptor is the actual selling point

A drug that prevents weight regain only matters if people can tolerate taking it. GLP-1 drugs lose a meaningful share of patients to nausea and vomiting during dose escalation, which is part of why so many people stop in the first place. Because TIX100 works through TXNIP rather than the GLP-1 receptor, it is not expected to carry those same gastrointestinal effects, though that claim rests on mechanism and early human safety data rather than a head-to-head trial against a GLP-1 drug.

Dr. Shalev, TIX100's lead researcher, put the ceiling on the claim herself: "If the weight maintenance observed in these preclinical studies is validated in humans, TIX100 could become a novel, non-GLP-1 option to support sustained weight management after medical weight loss intervention." That is a conditional statement, not an announcement, and it is worth reading it that way.

Where human trials actually stand

TIX100 already cleared an FDA Investigational New Drug review and completed a Phase 1a single-dose study in healthy volunteers, which TIXiMED reported as safe, well tolerated, and notable for lowering post-meal glucose, the first sign the drug does something metabolically relevant in a person rather than just a mouse. The Phase 1b trial now underway, a double-blind, placebo-controlled study giving TIX100 or placebo twice daily for 28 days across three dose groups, exists to build the longer safety record needed before TIXiMED moves into Phase 2a. That next phase targets recent-onset type 1 diabetes, the original reason TXNIP inhibition was studied at all. Obesity and weight maintenance are not the immediate clinical target, even though they generated the headline.

What this does, and does not, mean if you are on a GLP-1

Nothing changes for anyone currently taking or considering semaglutide or tirzepatide. TIX100 is not available, not being tested in people for weight regain, and years from any realistic approval even in a best case. What it does add is a genuine new mechanism to watch, distinct from the amylin drugs like petrelintide and the multi-receptor agonists that dominate the current pipeline. If a drug that is not a GLP-1 can hold off weight regain without GLP-1 side effects, that is a different tool than anything currently approved, not a competitor to it.

Until there is human data on the weight-regain question specifically, the practical guidance has not changed: tapering, resistance training, and protein intake are the levers with actual evidence behind them right now, covered in full in our guide to preventing GLP-1 weight rebound. TIX100 is worth tracking, not planning around.