The Food and Drug Administration is examining reports of suicidal thoughts and other possible side effects linked to a class of blockbuster obesity drugs and whether it needs to take regulatory action.

Driving the news: An update to the agency's adverse event reporting system cited the risk of suicidal ideation; alopecia, or hair loss; and inhalation of stomach contents is connected to drugs treating diabetes and weight loss that include Wegovy, Ozempic, Mounjaro and Zepbound.

• While the FDA cautioned there's no certainty that a suspected drug is responsible for side effects reported to the agency, past investigations have led to new warnings on drug labels, more safety studies and other precautions.
• Eli Lilly, the maker of Mounjaro and Zepbound, said in an emailed statement that it is collaborating with the FDA on potential safety issues. Novo Nordisk, which manufactures Wegovy and Ozempic, said it works closely with the FDA to continuously monitor the safety of all of its obesity drugs, adding known risks are reflected in their current labeling.

Context: Demand for the drugs — part of a class known as GLP-1 agonists — has exploded, even while experts note there isn't enough data about the long-term effects and how they work in certain populations, which could ultimately affect the market for them.

• The drugs, originally approved for diabetes, have become popular among people who just want to lose weight, presenting new risk-benefit calculations.
• GLP-1 labels already list the risk of suicidal thoughts.
• The European Medicines Agency, which did its own inquiry, said last month that while no conclusion can be drawn on a connection between the drugs and thoughts of self-harm, "there are several issues that still need to be clarified," and that regulators would revisit the matter in April.

Leerink analyst David Risinger wrote in an investor note that in light of skyrocketing demand for the drugs, "we expect ongoing FDA evaluation of risks and certain label updates going forward."

• The American Society of Anesthesiologists last June recommended that GLP-1 drugs be withheld prior to elective surgeries, citing the risk of patient regurgitation and inhalation of stomach contents while under anesthesia or sedation.
• Regarding alopecia, Risinger wrote that Wegovy showed a slightly higher frequency in clinical trials than placebo, but added that hair loss has been long reported as a side effect of rapid weight loss.

Tina Reed contributed to this report.