Did you know that Niacin is used for people to quit smoking? It's also a cure for depression. I took 4 tablets a day and noticed my mood was much better, even during the dreaded PMS days. I could immediately tell when I quit taking it due to running out. I've read that the Niacin that allows you to flush works more effectively, but when trying to buy it at a regular grocery store, you will find this flush-free version so you have to take a little more than recommended for the effects. Take it until you feel better and when you do, don't stop!