@hopeful33250, I've only been taking it two weeks or less. I got a bottle of a supplement blend that contains 10 mg of melatonin. I've always been hesitant to take that much. I've read and heard that our bodies don't need more than 3 mg, usually less, because throughout our younger life that is what our bodies produced. I'm 73 and had been taking a variety of supplements before bed so I could relax and sleep through the night. I usually have taken Ashwagandha, l-theanine, Valeria or 5-htp. In the past I've also occasionally taken GABA. This new product with the 10 mg of melatonin works very well, but I'm still concerned about the long-term effect of taking that much melatonin. Dr. Michael Breus, the Sleep Doctor, says it is not necessary.