Novo Nordisk has begun a late-stage clinical trial to evaluate whether lower doses of its oral pill, Wegovy, can still deliver weight reduction, reported Reuters.

According to the US clinical trials database, the company initiated the OASIS-5 study earlier this month, with the trial expected to run until 2028.

The move comes as Novo Nordisk faces growing competition from Eli Lilly in the obesity drug market, a sector projected to be worth more than $100bn by 2030.

The OASIS-5 trial will include 450 adults with a body mass index (BMI) of 30 or above, or 27 if accompanied by an obesity-related health issue, who have previously tried and failed to lose weight.

It is a 60-week, randomised study and will compare two unspecified lower strengths of oral semaglutide, the active ingredient in Wegovy, against a placebo.

The current approved long-term maintenance dose of Wegovy’s oral form is 25mg, but the pill is also available in doses of 1.5mg, 4mg, and 9mg. The company has not announced the specific lower doses to be tested in the trial.

The main goal is to determine whether these reduced doses enable participants to lose more weight than those on placebo.

Secondary outcomes include changes in waist circumference, other health markers, and monitoring of side effects.

The study is not enrolling patients with diabetes, those with major recent weight changes, or individuals currently using GLP-1-based therapies.

Novo Nordisk CEO Mike Doustdar told Reuters: “People are using low dosages of these products... they just decide on their own,” adding that patients often seek benefits beyond weight loss.

Eli Lilly did not respond to questions regarding any plans to investigate lower doses for its oral obesity drug.

In November 2025, Wegovy (semaglutide) reduced cardiovascular risk factors in the Phase III OASIS 4 trial.