It's funny that programmers (and their ilk) are constantly on the outlook for new ways to gain an edge by increasing focus, attention, and endurance, when two of the best substances for doing so have <i>long</i> been known: caffeine and nicotine. Consider – in both World Wars soldiers rations included coffee and cigarettes. There was a reason for that (and it wasn't just "comfort").<p>Now, you might say, what about the significant downsides for each of these? Well...yes. They are there, and they are fairly well understood.<p>There is a growing trend in pharmacology to try and get <i>most</i> of the benefits from some substance without <i>most</i> of the downsides. For example, the list of "new" antihistamines is long and growing every day. You know what the best antihistamine is? Benadryl! It just happens to come with a whole host of undesirable side-effects.<p>The problem, of course, is that for any "new" pharmaceutical, there's no way to be <i>really</i> sure of all the potential downsides until after they've been in use for some time. Take for example: Rofecoxib. Paracetemol (Tylenol) will destroy your liver, and aspirin and ibuprofen will tear up your stomach. Rofecoxib was supposed to bring all the benefits of these NSAIDs without the significant downsides...instead, it caused heart attacks!<p>So, not really a tip, but more of a caution/word of advice: if you want the <i>best</i> drugs to improve focus, attention, and endurance have a coffee and a cig. If you don't like the impact that has on your health, then keep in mind any alternatives you want to try could have less downsides...or more.<p>Maybe the best thing would be to get some rest and follow Michael Pollan's wonderful advice: "Eat food, mostly plants, not too much."