Phosphatidylserine is a fatty substance called a phospholipid. It covers and protects the cells in your brain and carries messages between them. Phosphatidylserine plays an important role in keeping your mind and memory sharp. Animal studies suggest that the level of this substance in the brain decreases with age. Why do people take phosphatidylserine? Phosphatidylserine is taken to try to prevent memory loss and mental decline that may occur as you get older. Several studies suggest that it may boost your brain power. People who took the supplement scored higher on short-term memory, mood, and concentration tests. For example, they could better recall names and objects. Much more research is needed to confirm these results. Scientists have used phosphatidylserine in studies to treat symptoms of Alzheimer's disease. Again, there is not enough evidence that phosphatidylserine is of any help in treating this condition. Phosphatidylserine has been suggested in the treatment of the following conditions, as well: Multiple sclerosis Muscle soreness and stress in athletes who overtrain.