Study shows lower doses of Novo Nordisk, Eli Lilly drugs still promote weight loss

A Reuters report on August 31, 2026 revealed that patients who stay on the lowest starter doses of GLP‑1 weight‑loss drugs still lose weight, though less than at the full, manufacturer‑recommended doses. The study compared Eli Lilly’s tirzepatide and Novo Nordisk’s semaglutide and found that even at low doses the drugs produce measurable weight loss and fewer nausea complaints. The data come from a large, real‑world analysis of patients who began therapy at the lowest approved doses and remained on treatment for a year.

The findings come at a time when the obesity‑drug market is expanding and patients are weighing cost, side‑effect profiles and long‑term tolerability. High‑dose regimens of these medications have been linked to nausea, dizziness and other adverse events that can prompt patients to stop therapy. By showing that lower doses still work, the study offers a potential compromise for patients who cannot afford the higher dose or who experience intolerable side effects. It also reflects the growing pressure on drug makers to provide flexible dosing options that can broaden their patient base.

In the study, low‑dose tirzepatide produced an average weight loss of 5.5 % over 12 months, compared with 20.2 % at the higher dose. Low‑dose semaglutide achieved 2.2 % loss versus 13.7 % at the higher dose. However, the low‑dose tirzepatide group reported higher rates of constipation, muscle cramps and kidney injury than the low‑dose semaglutide group. These differences may influence prescribing habits as physicians weigh the trade‑off between efficacy and tolerability.

The results could shape the future of the obesity‑drug market, which analysts expect to exceed $100 billion annually by 2030. While lower doses may reduce revenue per patient, they could improve adherence and expand the market for both injectable and oral GLP‑1 therapies. Novo Nordisk’s upcoming Wegovy pill and Eli Lilly’s continued growth of Zepbound and Mounjaro may hinge on how well lower‑dose regimens can meet patient needs while maintaining commercial viability.