Will 3mgs of melatonin help me stay asleep? i sleep fine for first 3 hours then not at all or poorly thereafter, despite proper sleep hygiene.

Melatonin: Consider other factors as well as Melatonin for improving sleep: https://sleepfoundation.org/ask-the-expert/sleep-hygiene Be sure you take Melatonin 30-60 min before sleep. Dose can increase to 10 mg. If insomnia persists, see your pcp to rule out medical conditions that may disturb sleep: https://sleepfoundation.org/insomnia/content/what-causes-insomnia I hope this helps.