Melatonin Capsules Other Key Ingredients: Our sleep and mood support supplement includes a serotonin complex and botanical extracts to help improve sleep, mood, and digestion. Unique Extra Strength Melatonin Complex: Our natural sleep capsules for adults are a great way to help your body recover. Our sleep melatonin capsules are non-GMO and third-party lab tested. Changes in daily habits, changes in seasons, and screen time before bed can disrupt melatonin production and throw us out of this cycle. Melatonin supplements can help. Melatonin supplements may help improve sleep quality in adults whose melatonin levels naturally decline with age.