Hi, @iblancoc - welcome to Mayo Clinic Connect.

I moved your post here so you could chat with others talking about melatonin dosing:

- What is the starting dose for Melatonin? Is this good for Insomnia?https://connect.mayoclinic.org/discussion/what-is-the-starting-dose-for-melatonin-is-this-good-for-insomnia

Have you had the chance to talk to your cardiologist about this? If so, what did he or she say?