GNC Melatonin 3mg is a supplement that offers a natural way to support restful sleep. Your body naturally produces this hormone in your pineal gland and creates less of this sleep-influencing substance during the day and more at night. Melatonin 3mg for sleep may be beneficial if you have a sleep schedule that frequently changes. Free of soy, wheat, dairy and gluten to accommodate individuals with sensitivities to common allergens. As a dietary supplement, take one tablet before bedtime. Do not exceed one tablet in any 24-hour period.