Melatonin supplements are often used by people who struggle to fall asleep. This is because melatonin doesn’t need a prescription is generally safe and has a low profile of adverse effects. Ambien is a sleeping pill that is often more potent and is frequently prescribed by a doctor because a patient suffers from real, chronic insomnia or sleep problems; they are generally quick-starting, designed to help the patient fall asleep faster and can sometimes become dependent-forming based on the dosage or duration of use.