Caffeine, the mild stimulant found in coffee, improves mental acuity, though the drink's enthusiasts -- who guzzle 120,000 tons of the stuff each year -- likely already know that. Aside from caffeine's brain boosting effects, coffee's antioxidant richness helps maintain brain health. And some research suggests that drinking coffee can actually stave off depression in women.
Today, extraordinary research is showing that bacopa has the remarkable ability to increase levels of BDNF, a protein responsible for the growth, maintenance and survival of neurons, and the creation of new neural connections in the brain. It also has been shown to help promote the growth of new neurons and neural pathways, which helps to explain why it’s such a powerful memory and concentration booster.
The blood half-life is 12-36 hours; hence two or three days ought to be enough to build up and wash out. A week-long block is reasonable since that gives 5 days for effects to manifest, although month-long blocks would not be a bad choice either. (I prefer blocks which fit in round periods because it makes self-experiments easier to run if the blocks fit in normal time-cycles like day/week/month. The most useless self-experiment is the one abandoned halfway.)
(People aged <=18 shouldn’t be using any of this except harmless stuff - where one may have nutritional deficits - like fish oil & vitamin D; melatonin may be especially useful, thanks to the effects of screwed-up school schedules & electronics use on teenagers’ sleep. Changes in effects with age are real - amphetamines’ stimulant effects and modafinil’s histamine-like side-effects come to mind as examples.)
According to Dr. Cohen, there’s no incentive for these companies to conduct trials to determine if their products actually do anything, so few of them do. In fact, he says he isn’t aware of any studies on nootropics that meet the research gold standard: double-blind, placebo-controlled, comparing meaningful numbers of healthy adults (not laboratory mice or rats) in terms of relevant measures of cognitive enhancement.
Consider something as simple as a phone call. You hear the phone ring – your auditory capacity kicks in. Next, you decide whether to answer – decision-making comes into play. You reach for the phone – calling your motor skills to work. You answer – using your voice – all controlled by your brain, all done in mere moments, without conscious thought. Your brain works non-stop, consuming mental energy and physical resources.
l-theanine (Examine.com) is occasionally mentioned on Reddit or Imminst or LessWrong33 but is rarely a top-level post or article; this is probably because theanine was discovered a very long time ago (>61 years ago), and it’s a pretty straightforward substance. It’s a weak relaxant/anxiolytic (Google Scholar) which is possibly responsible for a few of the health benefits of tea, and which works synergistically with caffeine (and is probably why caffeine delivered through coffee feels different from the same amount consumed in tea - in one study, separate caffeine and theanine were a mixed bag, but the combination beat placebo on all measurements). The half-life in humans seems to be pretty short, with van der Pijl 2010 putting it ~60 minutes. This suggests to me that regular tea consumption over a day is best, or at least that one should lower caffeine use - combining caffeine and theanine into a single-dose pill has the problem of caffeine’s half-life being much longer so the caffeine will be acting after the theanine has been largely eliminated. The problem with getting it via tea is that teas can vary widely in their theanine levels and the variations don’t seem to be consistent either, nor is it clear how to estimate them. (If you take a large dose in theanine like 400mg in water, you can taste the sweetness, but it’s subtle enough I doubt anyone can actually distinguish the theanine levels of tea; incidentally, r-theanine - the useless racemic other version - anecdotally tastes weaker and less sweet than l-theanine.)
Eventually one morning you wake up and realize it has been years since you felt like yourself. It takes so much more effort than it did before to string thoughts together. Your clarity is gone, you can never focus for more than two seconds at a time, and penetrating insights have been replaced by a swamp of distraction, confusion, and forgetfulness. Your thoughts feel frayed, worn—like ragged fabric flapping in the breeze.
Phillips told me that, much as he believes in neuroenhancers, he did not want to be "the poster boy for smart-in-a-pill". At one point, he said: "We really don't know the possible implications for long-term use of these things." (He recently stopped taking Provigil every day, replacing it with another prescription stimulant.) Nor does he think we need to be turning up the crank another notch on how hard we work. "But," he said, "the baseline competitive level is going to reorientate around what these drugs make possible, and you can choose to compete or not."
Panax ginseng – A review by the Cochrane Collaboration concluded that "there is a lack of convincing evidence to show a cognitive enhancing effect of Panax ginseng in healthy participants and no high quality evidence about its efficacy in patients with dementia." According to the National Center for Complementary and Integrative Health, "[a]lthough Asian ginseng has been widely studied for a variety of uses, research results to date do not conclusively support health claims associated with the herb."