Key Takeaways
- •Two newly published clinical trials from Eli Lilly suggest that patients who have lost substantial weight on injectable GLP-1 medications may be able to keep most of that weight off by switching to lower dose injections or an oral pill.
- •In one study, called Surmount-Maintain and published in *The Lancet*, researchers examined what happened when patients who had achieved significant weight loss on Lilly’s high dose Zepbound (tirzepatide) were assigned to either continue the same dose, switch to a lower 5 milligram dose, or take a placebo for another year.
- •The GLP-1 receptor agonists have reshaped the way clinicians think about weight management.
Eli Lilly Studies Show Potential for Maintaining GLP-1 Weight Loss with Lower Doses or Pills
Two newly published clinical trials from Eli Lilly suggest that patients who have lost substantial weight on injectable GLP-1 medications may be able to keep most of that weight off by switching to lower dose injections or an oral pill. The research, which was presented at a European obesity conference on May 13, 2026, and simultaneously published in peer reviewed medical journals, addresses a persistent challenge in obesity medicine: many patients stop taking the injections over time, and the weight often returns.
In one study, called Surmount-Maintain and published in The Lancet, researchers examined what happened when patients who had achieved significant weight loss on Lilly’s high dose Zepbound (tirzepatide) were assigned to either continue the same dose, switch to a lower 5 milligram dose, or take a placebo for another year. The other trial, named Attain-Maintain and published in Nature Medicine, looked at patients who had lost weight on either Zepbound or Novo Nordisk’s Wegovy (semaglutide) and then transitioned to Lilly’s newly launched oral pill, Foundayo (orforglipron), for a 12 month maintenance period.
The Persistence Problem with Injectable GLP-1 Drugs
The GLP-1 receptor agonists have reshaped the way clinicians think about weight management. These drugs mimic a natural hormone that regulates appetite, slows gastric emptying, and improves blood sugar control. Yet despite their proven effectiveness, a fundamental issue remains. Many patients find the idea of lifelong weekly injections unappealing, and real world data show that a large portion of them discontinue treatment within a year.
When patients stop taking these drugs, the weight they lost often returns quickly. This phenomenon has prompted researchers to search for “maintenance strategies” that could help people sustain their results with less intensive regimens. As the authors of the Nature Medicine paper wrote, “The GLP-1 injections have proven to be highly efficacious and safe for use, but persistence on therapy remains challenging.” The new trials from Lilly offer some of the first controlled data on whether lowering the dose or switching to an oral medication can preserve weight loss.
Surmount-Maintain: Lowering the Dose After High Dose Zepbound
The Surmount-Maintain trial enrolled patients who had initially lost an average of about 50 pounds (approximately 22.7 kilograms) after 60 weeks of treatment with the highest tolerated dose of Zepbound. These individuals were then randomly assigned to one of three maintenance arms for an additional 12 months: continue the same high dose, switch to a 5 mg dose (which is the lowest approved maintenance dose for Zepbound), or receive a placebo.
Results showed that the group remaining on the high dose continued to lose weight, dropping an average of nearly two more pounds over the year. Patients who moved to the 5 mg dose gained back an average of about 12 pounds. Those on placebo regained substantially more, though the source article did not specify the exact number for the placebo group. The key takeaway is that even a reduced dose of Zepbound was able to blunt the weight regain that typically occurs after stopping the drug entirely.
The study was published in The Lancet, one of the world’s most respected general medical journals. The findings suggest that clinicians may have flexibility in tailoring maintenance regimens to individual patient preferences and tolerance, potentially improving long term adherence.
Attain-Maintain: Switching from Injections to a Pill
The Attain-Maintain trial, published in Nature Medicine, took a different approach. Instead of adjusting the dose of an injectable, researchers tested whether patients could switch to an oral medication after losing weight on an injection. Participants had completed an initial treatment period on either Wegovy or Zepbound. Those who had been on Wegovy had lost an average of 41 pounds (about 18.6 kg), while those on Zepbound had lost an average of 55 pounds (about 24.9 kg).
All patients then transitioned to Lilly’s Foundayo (orforglipron), a once daily oral GLP-1 agonist that the company brought to market in 2025. After 12 months, the Wegovy graduates had gained back only about two pounds on average. The Zepbound graduates regained roughly 11 pounds. In both groups, the oral pill performed significantly better than placebo in preventing weight regain.
Lilly had previously given investors a preview of these results in December 2025, but the full data set was presented for the first time at the European obesity conference and in the Nature Medicine publication. The findings are particularly noteworthy because oral formulations could address the injection fatigue that drives many patients to stop treatment. Taking a daily pill may feel less burdensome than weekly shots, and the Attain-Maintain results indicate that orforglipron can maintain much of the weight loss achieved by either tirzepatide or semaglutide.
Scientific Context and Clinical Implications
The GLP-1 class works by activating receptors in the brain that regulate satiety and reward, effectively reducing appetite and food intake. When the drug is withdrawn, those pathways revert to their baseline state, and hunger signals often intensify. This biological rebound explains why weight regain is so common after discontinuation. The new trials suggest that maintaining some level of GLP-1 agonism, even at a lower intensity or via a different route of administration, can keep the metabolic brakes partially engaged.
It is important to note that the patients in these studies were a highly selected group. They had already demonstrated the ability to lose a large amount of weight and to tolerate the medications well. Whether the same maintenance strategies would work for patients who had lost less weight or who had experienced side effects is not yet clear. Additionally, the studies were funded by Lilly, and independent replication will be important.
Nonetheless, the data address a pressing clinical need. Weight loss maintenance has long been the weak link in obesity treatment. Lifestyle interventions alone often fail over the long term because the body adapts to a lower weight by increasing hunger and slowing metabolism. Pharmacological maintenance could provide a bridge, helping patients sustain their results without requiring the maximal doses that may be more expensive or harder to tolerate.
For the pharmaceutical industry, the results open new commercial opportunities. Lilly’s Foundayo pill, if approved for maintenance indications, could capture patients who started on competitor drugs like Wegovy. And the ability to drop from a high dose to a lower one could make therapy more affordable and acceptable for insurers and patients alike.
Frequently Asked Questions
Q: What exactly did the Surmount-Maintain and Attain-Maintain trials show?
A: Surmount-Maintain, published in The Lancet, showed that patients who had lost about 50 pounds on high dose Zepbound kept losing slightly more weight if they stayed on the same dose, but those who switched to a 5 mg dose regained about 12 pounds over a year. Attain-Maintain, published in Nature Medicine, showed that patients who had lost weight on either Wegovy (41 pounds) or Zepbound (55 pounds) and then switched to the oral pill Foundayo regained only 2 and 11 pounds respectively, far less than placebo.
Q: Why is weight regain so common after stopping GLP-1 injections?
A: GLP-1 drugs work by suppressing appetite and slowing digestion. When a person stops taking the drug, these effects vanish, and the brain’s natural hunger signals return to full strength. The body also adapts to a lower weight by reducing metabolic rate, making it easier to regain fat. Persistence on some form of GLP-1 therapy appears to counteract these biological pressures.
Q: Could these results change how doctors prescribe GLP-1 medications?
A: Possibly. Many clinicians currently prescribe the highest tolerated dose for weight loss and then simply stop or reduce the dose without clear guidance. The new data provide evidence that a lower dose of Zepbound (5 mg) or switching to an oral drug like Foundayo can help maintain much of the lost weight. This may lead to more structured maintenance protocols and better long term outcomes.
Q: Were these studies published in reputable journals?
A: Yes. Surmount-Maintain appeared in The Lancet, one of the most prestigious general medical journals, and Attain-Maintain was published in Nature Medicine, a leading journal for biomedical research. Both studies were also presented at a European obesity conference on the same day, May 13, 2026.