Roche Holding AG said it isn’t concerned about side effects in a small study of a weight-loss shot, after details about the trial sent shares tumbling on Monday.

Roche Holding AG’s shares slid the most in more than a month after its closely-watched experimental obesity pill was tied to side effects, raising questions about the drugmaker’s competitiveness in the hottest new pharmaceutical market.

Roche is holding out hopes that its injectable obesity prospect could eventually demonstrate 25% weight loss in late-stage trials, the pharma’s head of metabolism R&D has told Fierce Biotech.

Roche Holding AG said side effects in a highly anticipated study of its experimental obesity pill were milder when it eased patients into higher doses more slowly, seeking to reassure investors that it can compete in the next generation of weight loss drugs.

The novel drugs work by mimicking the gut hormone GLP-1, which lowers blood sugar and limits the appetite. Treatments such as Eli Lilly’s Mounjaro also add another gut hormone, GIP, that appears to enhance weight loss. In addition, companies are experimenting with other gut and pancreatic hormones.

Shares in Roche fell on Thursday after an early-stage obesity pill candidate that carries high market hopes was linked to a high rate of temporary side effects in its initial test phase on humans. Roche shares were down 4% at the open at 0700 GMT after the company presented late on Wednesday details on the trial.

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Shares of Roche (SIX:RO) fell on Thursday following reports from an early-stage trial of an obesity medication, which showed a high rate of temporary side effects. At 4:44 am (0844 GMT), Roche was trading 4% lower at