Are there any melatonin receptor antagonists, especially ones that people can use during the daytime?

Melatonin receptors: Presumably melatonin receptor antagonists would keep people awake at night. Melatonin is secreted by the pineal gland. This helps us regulate what is called a circadian rhythm. There are no melatonin receptor antagonists available at this time.

Rozerum: Rozerum is the only melatonin receptor agonist on the market. It is approved for shift work disorder.