Natural Highs, Feel Good All the Time, by Hyla Cass M.D.  and Patrick Holford is one of my favorite books of all time.

It talks about how to get your brain working better and happier with natural supplements. Specifically, amino acids which are the building blocks of protein.

Chapter 5 is entitled, Natural Energizers

First the authors discuss some of the popular stimulants of today that are not so healthy. Many of us are choking down way to much caffeine on a daily basis. There are better alternatives for boosting energy. They go into detail on several adaptogens, such as ginseng, Rhodiola and Ashwaganda. These non-caffeinated herbs are a healthier way to go. They don’t provide the same jolt as caffeine, but are better for the body overall.
According to Wikipedia: The term adaptogen is used by herbalists to refer to a natural herb product that is proposed to increase the body’s resistance to stress, trauma, anxiety and fatigue. In the past, they have been called rejuvenating herbs, qi tonics, rasayanas, or restoratives. All adaptogens contain antioxidants, but antioxidants are not necessarily adaptogens and that is not proposed to be their primary mode of action.
Then they talk about amino acids. DL-Phenylalanine is one I particularly like. It works for me and I notice an increase in brain energy. There is a difference between the DL- and L- forms of Phenylalanine. The DL form can help enhance the action of endorphins. These are the brains natural pain killers, and are thought to be responsible for “Runner’s High” That wonderful feeling you get when exercising intensely for a period of time.

Amino Acids for Brain Energy

• L-Phenylalanine
• DL Phenylalanine
• Tyrosine

One of my other favorite amino acids for energy is L-arginine. The authors don’t mention it in the book, it’s more for physical energy and heart health. I take a good dose before working out and it provides a noticeable difference in physical energy.