2yr old 31 pounds ate half of a 3mg oly melatonin and muscle relief gummy. should i go to the er??

1-1/2 mg of melatonin ingested by a 31-pound 2-year-old will likely have no effect. Though never actually calculated, Melatonin has a high margin of safety (lethal dose/divided by the effective dose). Nevertheless, using sleep aids for kids under 5 and healthy kids of any age is not recommended. In the future for a question like this needing immediate response, call poison control 1-800-222-1222