Its really good for flight crew because it helps with fatigue, weight gain, depression, and other stuff we face with this job....I have been using it since November and I honestly do feel a difference. Not to say I have all the energy in the world but instead of hopping in bed as soon as I get to my hotel, I feel this push to get out and be productive. Which is really what it came down to for me. I was sleeping way too much and isolating myself on layovers as well as home. It also helps improve my mood and my sleep!