I noticed a change the day I started taking Life's Fortune Multi-Vitamin/Minerals. That's nothing new. I've experienced it with other vitamins. For the first few days I was able to go about my tasks with sufficient energy to complete them, plus they didn't upset my stomach the way certain other vitamins have. After a while I stopped noticing any change, and so decided to take a week off from the vitamins. That entire week I was tired, tired, tired. I am now convinced that these vitamins really do make a difference to my energy and health, and I hope to continue taking them for a long, long while.