New fat jab targets metabolism to boost weight loss without dieting, researchers say

A potential new obesity drug, RES-010, aims to trigger weight loss by reprogramming how the body handles fat and energy rather than by suppressing appetite, according to researchers. The therapy is in early human testing, with initial safety assessments underway in a phase 1 trial in the Netherlands as researchers explore whether it can offer lasting metabolic benefits without requiring people to eat less.

The drug targets a molecule called miR-22, which scientists say helps regulate how fats are metabolised and how energy within cells is used or stored. Proponents say RES-010 works by reprogramming cellular metabolism to boost mitochondrial activity and promote the conversion of white fat, which stores energy, into brown fat, which burns energy. Dr. Ricardo Panella, co-founder and CEO of Resalis Therapeutics, described the approach as shifting focus from appetite suppression to fundamental metabolic changes, with the aim of longer-lasting weight loss and broader health gains, including potential improvements in liver health.

Early data from animal studies suggest the approach could impact weight independently of food intake. In a study described as Reprogramming Obesity, obese mice receiving weekly RES-010 injections lost about 12% more weight than untreated mice, despite both groups consuming the same amount of food. Importantly, the treated mice did not regain weight after the treatment ended, a finding researchers say supports the idea that RES-010 is altering metabolism rather than merely suppressing appetite. The research team plans to present these results at the European Association for the Study of Diabetes conference in Vienna, Austria.

Experts cautioned that the work remains preliminary. The study has not yet undergone peer review, and some outside scientists urged restraint in interpreting “metabolic reprogramming.” Dr. Adam Collines, a professor of nutrition at the University of Surrey who was not involved in the research, told The Telegraph he was wary of claims that a drug could reprogram metabolism without fully understanding effects on fat storage and mitochondrial function.

Despite the cautious tone, proponents argue RES-010 could represent a first-in-class approach to obesity treatment that targets the root metabolic drivers rather than just appetite signals. The drug is currently in a phase 1 trial to evaluate safety in up to 80 healthy and overweight individuals in the Netherlands. The first participants started treatment in November 2024, with initial safety findings anticipated early next year. If safety is established, the program could move on to larger studies to assess effectiveness in promoting weight loss and improving metabolic health.

Another context shaping the conversation around obesity treatment is the ongoing exploration of higher-dose obesity medications. In recent trials, a triple-strength version of Wegovy (semaglutide) has demonstrated greater weight loss than standard doses, sparking discussion about megadoses as an option for patients not achieving sufficient results on current therapy. The potential for increased weight loss must be weighed against side effects, with nausea, vomiting, diarrhea and constipation among the most commonly reported adverse effects at higher doses. In the United Kingdom, estimates suggest fewer than 200,000 people access prescription weight loss injections through the NHS, while more than 1.4 million are believed to use them privately, according to health think tanks.

Lean mass preservation remains a key concern with current weight loss drugs. Research has shown that a substantial portion of weight loss from some therapies comes from muscle loss, with potential implications for strength, stamina and insulin regulation. Dr. Panella noted that lean mass preservation is a central goal for RES-010, pointing to animal data where the new jab led to only about 1% lean mass loss over ten weeks, compared with roughly 8% for a comparator therapy in similar studies, suggesting a potential advantage if reflected in humans.