I've been supplementing for almost 2 years. It still works. I unfortunately need a lifetime supply. I almost take it every day. So 0.3 mg * 300 days * 100 year

I've been supplementing for almost 2 years. It still works. I unfortunately need a lifetime supply. I almost take it every day. So 0.3 mg * 300 days * 100 years = 9 grams of melatonin. I don't expect to live 100 years but it's handy to have a bit of an oversupply.