New research raises concerns about a popular sleep aid that many people think is safe and natural.  We’re talking about melatonin and whether taking it long-term could affect your heart.

Is melatonin ever appropriate? Yes. Dr. Klein says it’s safe starting at age 2, though definitely loop in your pediatrician before age 3. It can be genuinely helpful for jet lag, for kids with specific conditions affecting sleep, or when sleep issues are seriously impacting daily life.

Melatonin is in the spotlight again, with new research raising questions about its safety and effectiveness. The popular sleep aid continues to line store shelves and flood social media, and it's easy to feel confused about what's fact and what's hype.

Here, experts explain when to take melatonin for best results, plus the drug interactions and other things you need to know about using melatonin for sleep. Once you’ve discussed with your healthcare provider and been given the go-ahead to add the supplement to your routine, of course.