One of the other suggested benefits is for boosting serotonin levels; low levels of serotonin are implicated in a number of issues like depression. I’m not yet sure whether tryptophan has helped with motivation or happiness. Trial and error has taught me that it’s a bad idea to take tryptophan in the morning or afternoon, however, even smaller quantities like 0.25g. Like melatonin, the dose-response curve is a U: ~1g is great and induces multiple vivid dreams for me, but ~1.5g leads to an awful night and a headache the next day that was worse, if anything, than melatonin. (One morning I woke up with traces of at least 7 dreams, although I managed to write down only 2. No lucid dreams, though.)
Your mileage will vary. There are so many parameters and interactions in the brain that any of them could be the bottleneck or responsible pathway, and one could fall prey to the common U-shaped dose-response curve (eg. Yerkes-Dodson law; see also Chemistry of the adaptive mind & de Jongh et al 2007) which may imply that the smartest are those who benefit least23 but ultimately they all cash out in a very few subjective assessments like energetic or motivated, with even apparently precise descriptions like working memory or verbal fluency not telling you much about what the nootropic actually did. It’s tempting to list the nootropics that worked for you and tell everyone to go use them, but that is merely generalizing from one example (and the more nootropics - or meditation styles, or self-help books, or getting things done systems - you try, the stronger the temptation is to evangelize). The best you can do is read all the testimonials and studies and use that to prioritize your list of nootropics to try. You don’t know in advance which ones will pay off and which will be wasted. You can’t know in advance. And wasted some must be; to coin a Umeshism: if all your experiments work, you’re just fooling yourself. (And the corollary - if someone else’s experiments always work, they’re not telling you everything.)
Unlike many hypothetical scenarios that bioethicists worry about - human clones, "designer babies" - cognitive enhancement is already in full swing. But how much do they actually help? Are they potentially harmful or addictive? Then there's the question of what we mean by "smarter". Could enhancing one kind of thinking exact a toll on others? All these questions need proper scientific answers, but for now much of the discussion is taking place furtively, among the increasing number of people who are performing daily experiments on their own brains.
The evidence? Found helpful in reducing bodily twitching in myoclonus epilepsy, a rare disorder, but otherwise little studied. Mixed evidence from a study published in 1991 suggests it may improve memory in subjects with cognitive impairment. A meta-analysis published in 2010 that reviewed studies of piracetam and other racetam drugs found that piracetam was somewhat helpful in improving cognition in people who had suffered a stroke or brain injury; the drugs’ effectiveness in treating depression and reducing anxiety was more significant.
Mercury, as well as other heavy metals such as lead, can accumulate in brain tissue, as well as in the spinal cord, as they are fat-soluble - meaning that they can hide itself in fat tissue, which is abundant in both the brain and the spine. Once there, they can displace important nutrients for brain health such as zinc and iron, which are needed for neurotransmitter production, as well as induce an inflammatory process called oxidative stress among other things.
A pastor named John Piper said it well, “If hearing about God’s judgment makes it harder for us to love God, then probably the God we love is a figment of our imagination and not the real and true God. If we would love the true God, we must know the true God. There is something wrong with our faith if we cannot sing praises to God not only as our loving Father but also as the righteous Judge of all the earth.”
Reason: Vitamin B12 supports brain health in critical ways. The water-soluble B vitamin helps the body convert carbohydrates and fats into energy the brain needs to function properly. It also helps reduce the brain shrinkage often associated with cognitive disorders, supports healthy sleep-wake cycles (incredibly important, given what we now know about sleep and Alzheimer’s risk), and aids the proper “firing” of communications between neurons.
The BoredAt websites - which allow college students to chat idly while they're ostensibly studying - are filled with messages about Adderall. Posts like these, from the BoredAtPenn site, are typical: "I have some Adderall - I'm sitting by room 101.10 in a grey shirt and headphones"; "I have Adderall for sale 20mg for $15"; "I took Adderall at 8pm, it's 6:30am and I've barely blinked." On the Columbia site one poster complains that her friends take Adderall "like candy", adding: "I don't want to be at a disadvantage to everyone else. Is it really that dangerous? My grades weren't that great this year and I could do with a bump." A Columbia student responds: "It's probably not a good idea if you're not prescribed", but offers practical advice anyway: "Keep the dose normal and don't grind them up or snort them." Occasional dissenters ("I think there should be random drug testing at every exam") are drowned out by testimonials like this one, from the BoredAtHarvard site: "I don't want to be a pusher or start people on something bad, but Adderall is amazing."
The third category was cognitive control - how effectively you can check yourself in circumstances where the most natural response is the wrong one. A classic test is the Stroop Task, in which people are shown the name of a colour (let's say orange) written in a different colour (let's say purple). They're asked to read the word (which is easy, because our habitual response to a word is to read it) or to name the ink colour (which is harder, because our first impulse is to say "orange"). These studies presented a more mixed picture, but overall they showed some benefit "for most normal healthy subjects" - especially for people who had inherently poorer cognitive control.
They reduce inflammation, are high in cancer-protecting antioxidants and help rid your blood of toxins. The natural nitrates in beets actually boost blood flow to the brain, helping with mental performance. Plus, during tough workouts, beets actually help boost energy and performance levels. I love them roasted or in salads — try my sweet potato beet hash or beet and goat cheese salad for some creative new ways to eat this brain food.
One should note the serious caveats here: it is a small in vitro study of a single category of human cells with an effect size that is not clear on a protein which feeds into who-knows-what pathways. It is not a result in a whole organism on any clinically meaningful endpoint, even if we take it at face-value (many results never replicate). A look at followup work citing Rapuri et al 2007 is not encouraging: Google Scholar lists no human studies of any kind, much less high-quality studies like RCTs; just some rat followups on the calcium effect. This is not to say Rapuri et al 2007 is a bad study, just that it doesn’t bear the weight people are putting on it: if you enjoy caffeine, this is close to zero evidence that you should reduce or drop caffeine consumption; if you’re taking too much caffeine, you already have plenty of reasons to reduce; if you’re drinking lots of coffee, you already have plenty of reasons to switch to tea; etc.
(On a side note, I think I understand now why modafinil doesn’t lead to a Beggars in Spain scenario; BiS includes massive IQ and motivation boosts as part of the Sleepless modification. Just adding 8 hours a day doesn’t do the world-changing trick, no more than some researchers living to 90 and others to 60 has lead to the former taking over. If everyone were suddenly granted the ability to never need sleep, many of them would have no idea what to do with the extra 8 or 9 hours and might well be destroyed by the gift; it takes a lot of motivation to make good use of the time, and if one cannot, then it is a curse akin to the stories of immortals who yearn for death - they yearn because life is not a blessing to them, though that is a fact more about them than life.)
Of course learning, working memory and cognitive control represent just a few aspects of thinking. Farah concluded that studies looking at other kinds of cognition - verbal fluency, for instance - were too few and too contradictory to tell us much. Both Chatterjee and Farah have wondered whether drugs that heighten users' focus might dampen their creativity. After all, some of our best ideas come to us not when we sit down at a desk but rather when we're in the shower or walking the dog - letting our minds roam. Jimi Hendrix reported that the inspiration for "Purple Haze" came to him in a dream; the chemist Friedrich August Kekule claimed that he discovered the ring structure of benzene during a reverie in which he saw the image of a snake biting its tail. Farah told me: "There is some evidence that suggests that individuals who are better able to focus on one thing and filter out distractions tend to be less creative.
There is no official data on their usage, but nootropics as well as other smart drugs appear popular in the Silicon Valley. “I would say that most tech companies will have at least one person on something,” says Noehr. It is a hotbed of interest because it is a mentally competitive environment, says Jesse Lawler, a LA based software developer and nootropics enthusiast who produces the podcast Smart Drug Smarts. “They really see this as translating into dollars.” But Silicon Valley types also do care about safely enhancing their most prized asset – their brains – which can give nootropics an added appeal, he says.
Because smart drugs like modafinil, nicotine, and Adderall come with drawbacks, I developed my own line of nootropics, including Forbose and SmartMode, that’s safe, widely available, and doesn’t require a prescription. Forskolin, found in Forbose, has been a part of Indian Ayurvedic medicine for thousands of years. In addition to being fun to say, forskolin increases cyclic adenosine monophosphate (cAMP), a molecule essential to learning and memory formation. 
Beans. Beans are "under-recognized" and "economical," says Kulze. They also stabilize glucose (blood sugar) levels. The brain is dependent on glucose for fuel, Kulze explains, and since it can't store the glucose, it relies on a steady stream of energy -- which beans can provide. Any beans will do, says Kulze, but she is especially partial to lentils and black beans and recommends 1/2 cup every day.
As for newer nootropic drugs, there are unknown risks. “Piracetam has been studied for decades,” says cognitive neuroscientist Andrew Hill, the founder of a neurofeedback company in Los Angeles called Peak Brain Institute. But “some of [the newer] compounds are things that some random editor found in a scientific article, copied the formula down and sent it to China and had a bulk powder developed three months later that they’re selling. Please don’t take it, people!”
Racetams, such as piracetam, oxiracetam, and aniracetam, which are often marketed as cognitive enhancers and sold over-the-counter. Racetams are often referred to as nootropics, but this property is not well established. The racetams have poorly understood mechanisms, although piracetam and aniracetam are known to act as positive allosteric modulators of AMPA receptors and appear to modulate cholinergic systems.