Between 12 and 18 percent of participants dropped out of the trial because of side effects, a higher percentage than is typical in trials of existing weight loss drugs. The company said that at least some of those people dropped out because they thought they were losing too much weight, alarming some outside researchers. Eli Lilly sponsored the trial, which included 445 participants. The full data has not been published yet, so it’s difficult to make definitive conclusions about why patients dropped out.