For Occasional Sleeplessness. Suitable for Vegetarians. Melatonin is a neurohormone produced in humans by the pineal gland. A favorite of travelers it governs the body's circadian rhythms helping the body ease into restful sleep. Melatonin is also a potent antioxidant. The Benefit of Sublinguals. Some nutrients may break down during liver metabolism. The sublingual form is absorbed directly into the bloodstream via the blood vessels under the tongue and in the cheeks bypassing the liver and allowing for quick entry into the system.