Everyone in the trial regained weight after stopping their weight-loss drug. The question Fractyl Health set out to answer was whether a single procedure on the gut could make that regain smaller. The company says it did, at least over the first six months1.
In a large trial called REMAIN-1, people who got the company’s Revita procedure kept about 80% of the weight they had lost on tirzepatide (sold as Mounjaro and Zepbound), compared with 67% for people who got a fake, or sham, procedure12. That meets the first of the trial’s two main goals. The second, and the one the US Food and Drug Administration (FDA) is likely to weigh most, looks at one year and is not in yet1.
What happened
The main part of the trial enrolled 308 adults with obesity, a body mass index (BMI, a weight-for-height measure) between 30 and 45, and no type 2 diabetes, at more than 30 US sites1. Everyone first took tirzepatide until they had lost at least 15% of their body weight, then stopped1. They were then randomly assigned, two to one, to a single Revita procedure or a sham endoscopy. Neither the patients nor the people assessing them were told which one they got1. All participants also received diet and lifestyle counseling, according to the trial’s public registry entry3.
Revita is an outpatient procedure done through an endoscope, a thin tube passed down the throat. It resurfaces the lining of the duodenum, the first part of the small intestine just after the stomach4. Fractyl says chronic metabolic disease disrupts how this lining senses nutrients and sends signals, and that resetting it aims to restore healthy signaling1. That explanation is the company’s hypothesis; the trial measured weight, not the mechanism.
The numbers, and what they mean
In the main analysis, people in the Revita group regained an average of 5.1% of their body weight over six months, compared with 8.2% in the sham group. That analysis included 176 Revita patients and 74 sham patients1. The p-value, a measure of how likely a gap this size is to be chance, was 0.0023, which is very small1.
The difference works out to roughly three percentage points of body weight. Longevity.Technology, which covered the results, noted that “highly statistically significant” and “life-changing” are not the same thing1.
Some larger-sounding figures come from what researchers call post hoc analyses, slices of the data chosen after the main analysis, which are treated with more caution1:
- 32% of Revita patients were weight stable or still losing at six months, compared with 18% on sham1.
- The 47 patients who had at least 20 cm of the duodenum treated regained 3.8%, which the company describes as 53% less regain than sham1.
- The 107 patients with 12 to 18 cm treated regained 4.7%, or 43% less1.
Fractyl also said the gap between the groups widened at each check, nearly doubling from month three to month six1.
On safety, as of a September 24, 2026 data cut-off, the company reported no serious side effects tied to the device or procedure, no deaths, and no unexpected device problems. Side effects linked to treatment were mostly mild, and 94% appeared within a week of the procedure1. The study is still ongoing1.
What it does not show yet
These results come from Fractyl’s announcement. They have not been published in a journal or reviewed by outside scientists, and the trial registry lists no posted results3.
Six months is early. The trial’s second main goal asks whether more than half of Revita patients are still at least 5% below their pre-tirzepatide weight one year after stopping the drug13. That is a fixed target the FDA set in advance, not a comparison against the sham group1. The trial’s key secondary questions, including the longer-treatment group behind the 53% figure, are only formally tested after the one-year goal. Until then, those signals stay exploratory1.
The study also tested a specific situation: people who had lost at least 15% of their weight on one drug, tirzepatide, and who did not have type 2 diabetes3. It does not say how the procedure would do for people who lost less weight, used other drugs, or have diabetes. And the trial cannot yet say whether any benefit lasts beyond a year.
Earlier data from a smaller group in the same study gives a hint that regain continues past six months. In a separate 45-person “midpoint” group, average regain at six months was 4.5% with Revita and 7.5% with sham2. By one year, the same group had regained 7.8% and 13%, respectively5. That smaller group was not designed to prove a statistically meaningful difference5.
Who is behind it
Fractyl Health, a company based in Burlington, Massachusetts, and listed on Nasdaq under the ticker GUTS, sponsors and runs the trial43. Its co-founder and chief executive, Harith Rajagopalan, has described weight maintenance after these drugs as a major commercial opportunity, calling it a likely “transformative blockbuster new indication in obesity” in an earlier interview2. On the new results he said:
A randomized, double-blind trial of this size meeting its primary endpoint with this level of statistical significance signals the potential for a new therapeutic category in obesity care.
That quote was reported by Longevity.Technology1. Dr Adrian Dan, medical director of the Weight Management Institute at Summa Health, was also quoted in the announcement, saying the results offer the potential to change the standard of care in weight maintenance and that patients often ask whether they must stay on these drugs forever1. The sources do not say whether Dan has any role in the trial or financial ties to the company.
How it fits the field
Drugs like tirzepatide and Ozempic-style medicines can produce large weight loss, but weight tends to come back when people stop. Fractyl has cited trials showing regain of as much as 66% of lost weight within one year of stopping4. People stop for many reasons, including side effects, cost and not wanting to inject a drug for life, as Rajagopalan put it in July5.
Revita’s earlier weight data came from smaller or unblinded groups. In an open-label group called REVEAL-1, where everyone knew they got the procedure, 22 people were treated and those followed to one year kept about 78% of their prior weight loss, according to a company filing summary6. Without a sham comparison, results like that are hard to interpret, which is why the blinded result now matters more.
Revita was first developed for type 2 diabetes. It is approved in Germany for that use and has an FDA Breakthrough Device designation for insulin-treated type 2 diabetes4. The company’s large US diabetes trial, REVITALIZE-1, is listed as suspended on the trial registry, which does not give a reason7. In the US, Revita remains investigational; it carries the CE mark in the EU and UK1.
What to watch next
Fractyl has laid out a timeline1:
- Late 2026: a De Novo marketing application to the FDA, a route for new kinds of devices with no existing equivalent1.
- January 1, 2027: a dedicated US billing code for the procedure, Category III CPT code 1122T, takes effect1.
- Early 2027: one-year results from the main trial1. The registry lists the trial’s primary completion date as February 15, 20273.
- Late 2027 to early 2028: possible FDA authorization and a US launch, per the company1.
The FDA has said it will decide on the final regulatory path after reviewing the full safety data1. The one-year result, and whether the full data are published for outside scrutiny, will show whether the six-month gap holds.
