Tufts researchers design experimental four‑hormone peptide aimed at bariatric‑level weight loss

Tufts University scientists reported the design of an experimental “quadruple‑action” peptide intended to produce long‑lasting weight loss comparable to bariatric surgery while reducing side effects seen with current GLP‑1 therapies.

The compound, described in the Journal of the American Chemical Society, is built to activate four hormonal pathways — glucagon‑like peptide‑1 (GLP‑1), glucose‑dependent insulinotropic polypeptide (GIP), glucagon and peptide YY (PYY) — in a single molecule. Researchers said spreading effects across multiple targets could achieve greater fat loss without over‑stimulating any single pathway, which they suggest may lower rates of nausea and other adverse effects.

"We built a single experimental peptide that works like four hormones at once, so we’re not pushing one button too hard," lead author Tristan Dinsmore, PhD, said in an interview. He said the design uses GIP in part because GIP signaling has demonstrated anti‑nausea effects in preclinical models, which could counter nausea that higher doses of GLP‑1 and PYY sometimes produce.

Current widely used therapies such as semaglutide (marketed as Ozempic and Wegovy) mimic GLP‑1, and newer agents like tirzepatide (Mounjaro, Zepbound) combine GLP‑1 and GIP activity. The Tufts approach adds glucagon and PYY into a single engineered peptide with the stated goals of improving appetite suppression, enhancing metabolic rate and reducing weight regain and muscle loss associated with some GLP‑1 regimens.

The research team said laboratory data come from cell‑based assays; the compound has not yet been tested in animals or humans. "Choosing the safest, most effective balance of the four pathways will require in‑vivo studies and clinical trials," Dinsmore said. He cautioned that the molecule is a next‑generation concept and "is not a medicine you can get today."

Physicians and weight‑loss specialists emphasized both the promise and the limits of a multi‑target approach. Dr. Brett Osborn, a Florida neurosurgeon who treats patients with longevity and weight‑loss strategies, praised current GLP‑1 agents for their effectiveness but urged careful management to avoid muscle loss and malnutrition. He recommended adequate protein intake and regular strength training for people receiving these medications.

"Single‑agent GLP‑1s like Ozempic work for most people," Osborn said. "Side effects are manageable when an experienced physician supervises you."

Sue Decotiis, M.D., a medical weight‑loss physician in New York City, noted that appetite control, metabolic changes and blood‑sugar regulation are complex and that individual responses to any new mechanism will vary. She said careful patient monitoring, including body composition assessment and attention to protein, fiber and hydration, is important when people take weight‑loss drugs.

Obesity affects an estimated more than 40% of American adults and is linked to type 2 diabetes, heart disease, stroke, sleep apnea, high blood pressure and several cancers. Researchers said their goal is to develop medications that can safely lower that burden without the need for major surgery in some patients.

The Tufts authors framed the work as "design research" that demonstrates what might be possible in the next generation of metabolic medicines. They acknowledged limitations in the current study and said further preclinical and clinical work will be required to identify the optimal mix and dosing of the four pathways to maximize efficacy while minimizing harms.

Until such studies are completed and regulatory review is carried out, clinicians advised patients to follow current medical guidance for approved therapies. Dinsmore urged people using GLP‑1‑based drugs to continue working with their clinicians, and researchers said the next steps are animal testing followed by phased human clinical trials to determine safety, tolerability and effectiveness.

The development arrives amid heightened public and clinical interest in pharmacological tools for weight management. While some experts describe current drugs as highly effective for many patients, others emphasize the importance of lifestyle measures, nutrition and exercise as complements to medication. The Tufts team said the quadruple‑target design intends to preserve the benefits of existing therapies while addressing common side effects that can limit tolerability and long‑term adherence.