If you&#x27;re a nail biter, I can&#x27;t recommend N-Acetyl Cysteine enough. I was a nail biter for my entire life - I don&#x27;t think I&#x27;d used a clipper in over a few decades. On a recommendation I tried NAC and haven&#x27;t bitten my nails since. I don&#x27;t even take it anymore - after a few weeks the urge to bite never came back.<p>It was actually a key moment of enlightenment.<p>First, I realized how powerful, yet fragile habits can be. By forming habits, you can do things effortlessly for years on end without even thinking about it. At the same time, small interruptions can derail the behavior permanently.<p>And second, I realized that what we eat can influence our behavior in ways which are imperceptible. When I took NAC, I didn&#x27;t feel any different - I just didn&#x27;t bite my nails. It got me thinking that I should be more careful about what I put in my body, because even little things can make a big difference. Since then I&#x27;ve learned to cook, and now eat a far healthier diet than I used to.