And the drugs are not terribly difficult to get, depending on where you’re located. Modafinil has an annual global share of $700 million, with high estimated off-label use. Although these drugs can be purchased over the internet, their legal status varies between countries. For example, it is legal to possess and use Modafinil in the United Kingdom without a prescription, but not in United States.
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."
The information learned in the tasks reviewed so far was explicit, declarative, and consistent within each experiment. In contrast, probabilistic and procedural learning tasks require the subject to gradually extract a regularity in the associations among stimuli from multiple presentations in which the correct associations are only presented some of the time, with incorrect associations also presented. Findings are mixed in these tasks. Breitenstein and colleagues (2004, 2006) showed subjects drawings of common objects accompanied by nonsense word sounds in training sessions that extended over multiple days. They found faster learning of the to-be-learned, higher probability pairings between sessions (consistent with enhanced retention over longer delays). Breitenstein et al. (2004) found that this enhancement remained a year later. Schlösser et al. (2009) tested subjects’ probabilistic learning ability in the context of a functional magnetic resonance imaging (fMRI) study, comparing performance and brain activation with MPH and placebo. MPH did not affect learning performance as measured by accuracy. Although subjects were overall faster in responding on MPH, this difference was independent of the difficulty of the learning task, and the authors accordingly attributed it to response processes rather than learning.
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. 
I’ve been actively benefitting from nootropics since 1997, when I was struggling with cognitive performance and ordered almost $1000 worth of smart drugs from Europe (the only place where you could get them at the time). I remember opening the unmarked brown package and wondering whether the pharmaceuticals and natural substances would really enhance my brain.
I posted a link to the survey on my Google+ account, and inserted the link at the top of all gwern.net pages; 51 people completed all 11 binary choices (most of them coming from North America & Europe), which seems adequate since the 11 questions are all asking the same question, and 561 responses to one question is quite a few. A few different statistical tests seem applicable: a chi-squared test whether there’s a difference between all the answers, a two-sample test on the averages, and most meaningfully, summing up the responses as a single pair of numbers and doing a binomial test:
The stimulant now most popular in news articles as a legitimate “smart drug” is Modafinil, which came to market as an anti-narcolepsy drug, but gained a following within the military, doctors on long shifts, and college students pulling all-nighters who needed a drug to improve alertness without the “wired” feeling associated with caffeine. Modafinil is a relatively new smart drug, having gained widespread use only in the past 15 years. More research is needed before scientists understand this drug’s function within the brain – but the increase in alertness it provides is uncontested.
Companies already know a great deal about how their employees live their lives. With the help of wearable technologies and health screenings, companies can now analyze the relation between bodily activities — exercise, sleep, nutrition, etc. — and work performance. With the justification that healthy employees perform better, some companies have made exercise mandatory by using sanctions against those who refuse to perform. And according to The Kaiser Family Foundation, of the large U.S. companies that offer health screenings, nearly half of them use financial incentives to persuade employees to participate.
At small effects like d=0.07, a nontrivial chance of negative effects, and an unknown level of placebo effects (this was non-blinded, which could account for any residual effects), this strongly implies that LLLT is not doing anything for me worth bothering with. I was pretty skeptical of LLLT in the first place, and if 167 days can’t turn up anything noticeable, I don’t think I’ll be continuing with LLLT usage and will be giving away my LED set. (Should any experimental studies of LLLT for cognitive enhancement in healthy people surface with large quantitative effects - as opposed to a handful of qualitative case studies about brain-damaged people - and I decide to give LLLT another try, I can always just buy another set of LEDs: it’s only ~$15, after all.)
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!”
Several chemical influences can completely disconnect those circuits so they’re no longer able to excite each other. “That’s what happens when we’re tired, when we’re stressed.” Drugs like caffeine and nicotine enhance the neurotransmitter acetylcholine, which helps restore function to the circuits. Hence people drink tea and coffee, or smoke cigarettes, “to try and put [the] prefrontal cortex into a more optimal state”.
If you could take a pill that would help you study and get better grades, would you? Off-label use of “smart drugs” – pharmaceuticals meant to treat disorders like ADHD, narcolepsy, and Alzheimer’s – are becoming increasingly popular among college students hoping to get ahead, by helping them to stay focused and alert for longer periods of time. But is this cheating? Should their use as cognitive enhancers be approved by the FDA, the medical community, and society at large? Do the benefits outweigh the risks?
Also known as Arcalion or Bisbuthiamine and Enerion, Sulbutiamine is a compound of the Sulphur group and is an analog to vitamin B1, which is known to pass the blood-brain barrier easily. Sulbutiamine is found to circulate faster than Thiamine from blood to brain. It is recommended for patients suffering from mental fatigue caused due to emotional and psychological stress. The best part about this compound is that it does not have most of the common side effects linked with a few nootropics.
Amphetamine – systematic reviews and meta-analyses report that low-dose amphetamine improved cognitive functions (e.g., inhibitory control, episodic memory, working memory, and aspects of attention) in healthy people and in individuals with ADHD. A 2014 systematic review noted that low doses of amphetamine also improved memory consolidation, in turn leading to improved recall of information in non-ADHD youth. It also improves task saliency (motivation to perform a task) and performance on tedious tasks that required a high degree of effort.