A method of treating a human subject in need of melatonin therapy includes administering to a human subject a compressed tablet comprising melatonin, citric acid, and a cellulosic polymer. The melatonin, citric acid, and cellulosic polymer combine after ingestion to form an acidic hydrogel that dissolves the melatonin and is effective to provide a first release dose of melatonin for assisting in inducement of sleep and a subsequent sustained release dose of melatonin for assisting in sustaining sleep while in the human subjects gastrointestinal tract.
