Farah was one of several scholars who contributed to a recent article in Nature, "Towards Responsible Use of Cognitive Enhancing Drugs by the Healthy". The optimistic tone of the article suggested that some bioethicists are leaning towards endorsing neuroenhancement. "Like all new technologies, cognitive enhancement can be used well or poorly," the article declared. "We should welcome new methods of improving our brain function. In a world in which human workspans and lifespans are increasing, cognitive-enhancement tools - including the pharmacological - will be increasingly useful for improved quality of life and extended work productivity, as well as to stave off normal and pathological age-related cognitive declines. Safe and effective cognitive enhancers will benefit both the individual and society." The BMA report offered a similarly upbeat observation: "Universal access to enhancing interventions would bring up the baseline level of cognitive ability, which is generally seen to be a good thing."
There are a number of treatments for the last. I already use melatonin. I sort of have light therapy from a full-spectrum fluorescent desk lamp. But I get very little sunlight; the surprising thing would be if I didn’t have a vitamin D deficiency. And vitamin D deficiencies have been linked with all sorts of interesting things like near-sightedness, with time outdoors inversely correlating with myopia and not reading or near-work time. (It has been claimed that caffeine interferes with vitamin D absorption and so people like me especially need to take vitamin D, on top of the deficits caused by our vampiric habits, but I don’t think this is true35.) Unfortunately, there’s not very good evidence that vitamin D supplementation helps with mood/SAD/depression: there’s ~6 small RCTs with some findings of benefits, with their respective meta-analysis turning in a positive but currently non-statistically-significant result. Better confirmed is reducing all-cause mortality in elderly people (see, in order of increasing comprehensiveness: Evidence Syntheses 2013, Chung et al 2009, Autier & Gandini 2007, Bolland et al 2014).
At dose #9, I’ve decided to give up on kratom. It is possible that it is helping me in some way that careful testing (eg. dual n-back over weeks) would reveal, but I don’t have a strong belief that kratom would help me (I seem to benefit more from stimulants, and I’m not clear on how an opiate-bearer like kratom could stimulate me). So I have no reason to do careful testing. Oh well.

Microdosing with Iboga: Native to the rainforests in Central Africa, Iboga is an evergreen shrub, with high concentrations found in the root bark. It has a rich history amongst practitioners in the indigenous Bwiti religion in Africa and has recently found its way into Western practices, primarily for extremely effective therapy for drug addictions, but also for physical energy, cognitive performance in smaller microdoses, and a surge in positive emotions (See additional studies here and here.).  To microdose with Iboga, you will want to find it in tincture or root bark form (the root bark form is typically encapsulated). If using a tincture, find a source that has the root bark extracted into its purest form, combined with Iboga alkaloids, which keeps the full spectrum of the plant untouched. Just a single drop of an Iboga tincture equates to about 0.5 milligrams and suffices as a microdose. For the root bark of Iboga, a dose of 300-500 milligrams is also an effective dose. I’ve personally found Iboga to be most useful prior to a workout or an effort that combines both brain and body demands, such as tennis or basketball – but it makes you hyperactive and jittery if taken prior to a day of desk work. This makes sense when you consider that African tribes traditionally whipped themselves into a frenzied pre-battle state on Iboga.
Still, putting unregulated brain drugs into my system feels significantly scarier than downing a latte or a Red Bull—not least because the scientific research on nootropics’ long-term effects is still so thin. One 2014 study found that Ritalin, modafinil, ampakines, and other similar stimulants could eventually reduce the “plasticity” of some of the brain’s neural networks by providing them with too much dopamine, glutamate and norepinephrine, and potentially cause long-term harm in young people whose brains were still developing. (In fact, in young people, the researchers wrote, these stimulants could actually have the opposite effect the makers intended: “Healthy individuals run the risk of pushing themselves beyond optimal levels into hyperdopaminergic and hypernoradrenergic states, thus vitiating the very behaviors they are striving to improve.”) But the researchers found no evidence that normal doses of these drugs were harmful when taken by adults.

Bacopa Monnieri is probably one of the safest and most effective memory and mood enhancer nootropic available today with the least side-effects. In some humans, a majorly extended use of Bacopa Monnieri can result in nausea. Amongst AlternaScript’s, primary products is Optimind, a nootropic supplement which largely constitutes of Bacopa Monnieri as one of the main ingredients.


I’m sure your office already has a coffee maker, but if you’re in the mood for a refreshing coffee twist at the office, try this cold brew option from Chameleon Cold Brew. They use a highly select blend of 100% organic, fair trade certified Arabica coffee beans and filtered Texas Hill Country water. The result is a super smooth, less acidic and highly caffeinated coffee, which can be enjoyed hot or cold.
Kratom (Erowid, Reddit) is a tree leaf from Southeast Asia; it’s addictive to some degree (like caffeine and nicotine), and so it is regulated/banned in Thailand, Malaysia, Myanmar, and Bhutan among others - but not the USA. (One might think that kratom’s common use there indicates how very addictive it must be, except it literally grows on trees so it can’t be too hard to get.) Kratom is not particularly well-studied (and what has been studied is not necessarily relevant - I’m not addicted to any opiates!), and it suffers the usual herbal problem of being an endlessly variable food product and not a specific chemical with the fun risks of perhaps being poisonous, but in my reading it doesn’t seem to be particularly dangerous or have serious side-effects.
Feeling behind, I resolved to take some armodafinil the next morning, which I did - but in my hurry I failed to recall that 200mg armodafinil was probably too much to take during the day, with its long half life. As a result, I felt irritated and not that great during the day (possibly aggravated by some caffeine - I wish some studies would be done on the possible interaction of modafinil and caffeine so I knew if I was imagining it or not). Certainly not what I had been hoping for. I went to bed after midnight (half an hour later than usual), and suffered severe insomnia. The time wasn’t entirely wasted as I wrote a short story and figured out how to make nicotine gum placebos during the hours in the dark, but I could have done without the experience. All metrics omitted because it was a day usage.

Why? Just think for a moment how much visual, auditory, and sensory information you’re exposed to and required to process every day.  From constant background sounds to big city noise pollution, the phone ringing, artificial lighting, chemical-laden air fresheners circulating smells of fresh linen, electromagnetic fields piercing through your brain, the new procedure you have to learn at work, and a host of other sensory stimuli, the human brain has to organize and deal with this information all while keeping you upright and going. Although the brain has incredible skills and unimaginable capabilities, modern living creates unprecedented stress and sensory overload from all of the information that must be processed every single day.  Sensory overload has even been shown to cause irritability, anxiety, mood swings, depression, ADHD, fibromyalgia, PTSD and chronic fatigue syndrome. The ability of your brain to continue learning, processing, and forming new neural connections is key to maintaining optimal brain health and longevity.


The price is not as good as multivitamins or melatonin. The studies showing effects generally use pretty high dosages, 1-4g daily. I took 4 capsules a day for roughly 4g of omega acids. The jar of 400 is 100 days’ worth, and costs ~$17, or around 17¢ a day. The general health benefits push me over the edge of favoring its indefinite use, but looking to economize. Usually, small amounts of packaged substances are more expensive than bulk unprocessed, so I looked at fish oil fluid products; and unsurprisingly, liquid is more cost-effective than pills (but like with the powders, straight fish oil isn’t very appetizing) in lieu of membership somewhere or some other price-break. I bought 4 bottles (16 fluid ounces each) for $53.31 total (thanks to coupons & sales), and each bottle lasts around a month and a half for perhaps half a year, or ~$100 for a year’s supply. (As it turned out, the 4 bottles lasted from 4 December 2010 to 17 June 2011, or 195 days.) My next batch lasted 19 August 2011-20 February 2012, and cost $58.27. Since I needed to buy empty 00 capsules (for my lithium experiment) and a book (Stanovich 2010, for SIAI work) from Amazon, I bought 4 more bottles of 16fl oz Nature’s Answer (lemon-lime) at $48.44, which I began using 27 February 2012. So call it ~$70 a year.
Zach was on his way to being a doctor when a personal health crisis changed all of that. He decided that he wanted to create wellness instead of fight illness. He lost over a 100 lbs through functional nutrition and other natural healing protocols. He has since been sharing his knowledge of nutrition and functional medicine for the last 12 years as a health coach and health educator.
There are over a thousand websites and hundreds of reference guides chock full of complicated methods for combining many of the compounds you’ve just discovered. There’s a reason for this: the practice of “stacking” nootropics and smart drugs into specific combinations can be far more powerful and efficacious than consuming a single, lonely compound in isolation. For example, dosing choline sources with your morning coffee can make your brain feel fresh for hours or mixing curcumin with black pepper can dramatically amp up the neural anti-inflammatory effects of both compounds. Ultimately, a teaspoon of lion’s mane extract just isn’t as titillating as lion’s mane blended with caffeine, theanine, nicotine and a touch of vinpocetine.
Many people quickly become overwhelmed by the volume of information and number of products on the market. Because each website claims its product is the best and most effective, it is easy to feel confused and unable to decide. Smart Pill Guide is a resource for reliable information and independent reviews of various supplements for brain enhancement.
Analyzing the results is a little tricky because I was simultaneously running the first magnesium citrate self-experiment, which turned out to cause a quite complex result which looks like a gradually-accumulating overdose negating an initial benefit for net harm, and also toying with LLLT, which turned out to have a strong correlation with benefits. So for the potential small Noopept effect to not be swamped, I need to include those in the analysis. I designed the experiment to try to find the best dose level, so I want to look at an average Noopept effect but also the estimated effect at each dose size in case some are negative (especially in the case of 5-pills/60mg); I included the pilot experiment data as 10mg doses since they were also blind & randomized. Finally, missingness affects analysis: because not every variable is recorded for each date (what was the value of the variable for the blind randomized magnesium citrate before and after I finished that experiment? what value do you assign the Magtein variable before I bought it and after I used it all up?), just running a linear regression may not work exactly as one expects as various days get omitted because part of the data was missing.
More than once I have seen results indicating that high-IQ types benefit the least from random nootropics; nutritional deficits are the premier example, because high-IQ types almost by definition suffer from no major deficiencies like iodine. But a stimulant modafinil may be another such nootropic (see Cognitive effects of modafinil in student volunteers may depend on IQ, Randall et al 2005), which mentions:
I can test fish oil for mood, since the other claimed benefits like anti-schizophrenia are too hard to test. The medical student trial (Kiecolt-Glaser et al 2011) did not see changes until visit 3, after 3 weeks of supplementation. (Visit 1, 3 weeks, visit 2, supplementation started for 3 weeks, visit 3, supplementation continued 3 weeks, visit 4 etc.) There were no tests in between the test starting week 1 and starting week 3, so I can’t pin it down any further. This suggests randomizing in 2 or 3 week blocks. (For an explanation of blocking, see the footnote in the Zeo page.)
This is absolutely fantastic work - Dr. Mosconi's clear, concise prose readily breaks down the science of how we can protect our beloved brains from the horrors of dementia and keep our minds humming beautifully for years. Her mastery of the various key subjects - neurobiology, nutrition, biochemistry - is incredible and her ability to decode complex scientific findings into digestible, easy-to-use advice for the layperson is second to none. This is easily one of the best popular science books I've ever come across and by far the best read on nutrition I know of.

According to Dr Vivette Glover, Director of the Foetal and Neonatal Stress and Research Centre, at any one time during pregnancy, one in every ten women will be depressed and around one in every thirty will be depressed both during pregnancy and the postnatal period (1). It is not yet understood exactly what causes the symptoms associated to depression during and after pregnancy. However, factors such as the large changes that the body undergoes due to the demands of the growing foetus, as well as breastfeeding and potential sleep deprivation, can all play a significant role in how the body deals with stress. It is during this period of time that our bodies require more nourishment from food than ever and it can also be at exactly this time when we perhaps struggle to prioritise nutrition due to lack of energy, loss of appetite or sickness. 

* These statements have not been evaluated by the Food and Drug Administration. The products and information on this website are not intended to diagnose, treat, cure or prevent any disease. The information on this site is for educational purposes only and should not be considered medical advice. Please speak with an appropriate healthcare professional when evaluating any wellness related therapy. Please read the full medical disclaimer before taking any of the products offered on this site.
All clear? Try one (not dozens) of nootropics for a few weeks and keep track of how you feel, Kerl suggests. It’s also important to begin with as low a dose as possible; when Cyr didn’t ease into his nootropic regimen, his digestion took the blow, he admits. If you don’t notice improvements, consider nixing the product altogether and focusing on what is known to boost cognitive function – eating a healthy diet, getting enough sleep regularly and exercising. "Some of those lifestyle modifications," Kerl says, "may improve memory over a supplement."
Choline is very important for cognitive function because it is a precursor to Acteylcholine. Your body needs enough choline to convert into Acteylcholine to keep your brain healthy. For this reason, choline supplements are often considered great nootropics, even by themselves. CDP-Choline and Alpha GPC are the best sources for supplemental Choline.

1 PM; overall this was a pretty productive day, but I can’t say it was very productive. I would almost say even odds, but for some reason I feel a little more inclined towards modafinil. Say 55%. That night’s sleep was vile: the Zeo says it took me 40 minutes to fall asleep, I only slept 7:37 total, and I woke up 7 times. I’m comfortable taking this as evidence of modafinil (half-life 10 hours, 1 PM to midnight is only 1 full halving), bumping my prediction to 75%. I check, and sure enough - modafinil.
Nootropics – sometimes called smart drugs – are compounds that enhance brain function. They’re becoming a popular way to give your mind an extra boost. According to one Telegraph report, up to 25% of students at leading UK universities have taken the prescription smart drug modafinil [1], and California tech startup employees are trying everything from Adderall to LSD to push their brains into a higher gear [2].
Take at 10 AM; seem a bit more active but that could just be the pressure of the holiday season combined with my nice clean desk. I do the chores without too much issue and make progress on other things, but nothing major; I survive going to The Sitter without too much tiredness, so ultimately I decide to give the palm to it being active, but only with 60% confidence. I check the next day, and it was placebo. Oops.
Is lifestyle truly important, though? According to Dr. Lisa, "genes load the gun, but lifestyle pulls the trigger." As someone who grew up very aware of my genetic predisposition (diabetes, cardiovascular diseases, breast cancer — you name it and someone in my family has it), I always thought that this weighed heavily on whether or not someone manifests an illness. But, groundbreaking research on epigenetics actually states the contrary. 
Why? Just think for a moment how much visual, auditory, and sensory information you’re exposed to and required to process every day.  From constant background sounds to big city noise pollution, the phone ringing, artificial lighting, chemical-laden air fresheners circulating smells of fresh linen, electromagnetic fields piercing through your brain, the new procedure you have to learn at work, and a host of other sensory stimuli, the human brain has to organize and deal with this information all while keeping you upright and going. Although the brain has incredible skills and unimaginable capabilities, modern living creates unprecedented stress and sensory overload from all of the information that must be processed every single day.  Sensory overload has even been shown to cause irritability, anxiety, mood swings, depression, ADHD, fibromyalgia, PTSD and chronic fatigue syndrome. The ability of your brain to continue learning, processing, and forming new neural connections is key to maintaining optimal brain health and longevity.
This is a small water plant native to India. Bacopa is an adaptogen – it helps your body adapt to stress. It also improves memory in healthy adults[12] and enhances attention and mood in people over 65. [13] Scientists still don’t fully understand how Bacopa works, but they do know it takes time to work; study participants didn’t feel its memory-enhancing effects until they’d been supplementing with it daily for 4 weeks, so if you try Bacopa, stick with it for a month before you give up on it.
The next cheap proposition to test is that the 2ml dose is so large that the sedation/depressive effect of nicotine has begun to kick in. This is easy to test: take much less, like half a ml. I do so two or three times over the next day, and subjectively the feeling seems to be the same - which seems to support that proposition (although perhaps I’ve been placebo effecting myself this whole time, in which case the exact amount doesn’t matter). If this theory is true, my previous sleep results don’t show anything; one would expect nicotine-as-sedative to not hurt sleep or improve it. I skip the day (no cravings or addiction noticed), and take half a ml right before bed at 11:30; I fall asleep in 12 minutes and have a ZQ of ~105. The next few days I try putting one or two drops into the tea kettle, which seems to work as well (or poorly) as before. At that point, I was warned that there were some results that nicotine withdrawal can kick in with delays as long as a week, so I shouldn’t be confident that a few days off proved an absence of addiction; I immediately quit to see what the week would bring. 4 or 7 days in, I didn’t notice anything. I’m still using it, but I’m definitely a little nonplussed and disgruntled - I need some independent source of nicotine to compare with!
We already knew that rosemary oil has a variety of benefits, but did you know that the herb does, too? Carnosic acid, one of the main ingredients in rosemary, helps protect the brain from neurodegeneration. It does this by protecting the brain against chemical free radicals, which are linked to neurodegeneration, Alzheimer’s, strokes and normal aging in the brain. (10)
Exercise is also important, says Lebowitz. Studies have shown it sharpens focus, elevates your mood and improves concentration. Likewise, maintaining a healthy social life and getting enough sleep are vital, too. Studies have consistently shown that regularly skipping out on the recommended eight hours can drastically impair critical thinking skills and attention.
Brain Awake is produced by Irwin Naturals. The ingredients are natural and include some key ingredients. However, it also contained several other inactive ingredients that raised some concerns - namely, beeswax and silicone dioxide. We were not sure why these ingredients are included, and could not find any real explanation as to why they are contained within this product. That said, when we tested the ingredients in this product, they were as reported on the bottle.
A third of participants in clinical trials on Modafinil have reported crippling headaches.  An additional 11% experienced nausea, while others reported an array of other side-effects ranging from nervousness to diarrhea.  Dizziness and insomnia may also result from Modafinil use.   I can attest that the side effects are very real.  In fact, I had to stop using Modafinil after 2 days when my headaches became so intense I ended up at the ER.

Chatterjee told me that many people who come to his clinic are cognitively preoccupied versions of what doctors call the "worried well". He had just seen a middle-aged woman, a successful Philadelphia lawyer, who mentioned having to struggle a bit to come up with certain names. "Here's an example of someone who by most measures is doing perfectly fine," Chatterjee said. "She's not having any trouble at work. But she notices she's having some problems, and it's very hard to know how much of that is just getting older." Of course, people in her position could strive to get regular exercise and plenty of intellectual stimulation, both of which have been shown to help maintain cognitive function. But maybe they're already doing so and want a bigger mental rev-up, or maybe they want something easier than sweaty workouts and Russian novels: they want a pill.

Taking the tryptophan is fairly difficult. The powder as supplied by Bulk Nutrition is extraordinarily dry and fine; it seems to be positively hydrophobic. The first time I tried to swallow a teaspoon, I nearly coughed it out - the power had seemed to explode in my mouth and go down my lungs. Thenceforth I made sure to have a mouth of water first. After a while, I took a different tack: I mixed in as much Hericium as would fit in the container. The mushroom powder is wetter and chunkier than the tryptophan, and seems to reduce the problem. Combining the mix with chunks of melatonin inside a pill works even better.
Finally, it’s not clear that caffeine results in performance gains after long-term use; homeostasis/tolerance is a concern for all stimulants, but especially for caffeine. It is plausible that all caffeine consumption does for the long-term chronic user is restore performance to baseline. (Imagine someone waking up and drinking coffee, and their performance improves - well, so would the performance of a non-addict who is also slowly waking up!) See for example, James & Rogers 2005, Sigmon et al 2009, and Rogers et al 2010. A cross-section of thousands of participants in the Cambridge brain-training study found caffeine intake showed negligible effect sizes for mean and component scores (participants were not told to use caffeine, but the training was recreational & difficult, so one expects some difference).
Analyzing the results is a little tricky because I was simultaneously running the first magnesium citrate self-experiment, which turned out to cause a quite complex result which looks like a gradually-accumulating overdose negating an initial benefit for net harm, and also toying with LLLT, which turned out to have a strong correlation with benefits. So for the potential small Noopept effect to not be swamped, I need to include those in the analysis. I designed the experiment to try to find the best dose level, so I want to look at an average Noopept effect but also the estimated effect at each dose size in case some are negative (especially in the case of 5-pills/60mg); I included the pilot experiment data as 10mg doses since they were also blind & randomized. Finally, missingness affects analysis: because not every variable is recorded for each date (what was the value of the variable for the blind randomized magnesium citrate before and after I finished that experiment? what value do you assign the Magtein variable before I bought it and after I used it all up?), just running a linear regression may not work exactly as one expects as various days get omitted because part of the data was missing.
Another traditional Chinese brain booster is Danggui-Shaoyao-San (DSS). It has been suggested that DSS has potent beneficial angiogenesis and neurogenesis effects that may make it a potential treatment for ischemic stroke therapy. DSS is also known to beneficially impact free radical-mediated neurological diseases, exhibit anti-inflammatory and antioxidant activities and reduce cell death in the hippocampus, thereby promoting greater emotional, memory-related and autonomic nervous system function. Currently, there is limited research on proper dosage, but you can learn more about DSS in this fantastic summary article on it’s interplay with Alzheimer’s.
Like everything else in your body, the brain cannot work without energy. The ability to concentrate and focus comes from an adequate, steady supply of energy - in the form of glucose in our blood to the brain. Achieve this by choosing wholegrains with a low-GI, which release glucose slowly into the bloodstream, keeping you mentally alert throughout the day. Opt for 'brown' wholegrain cereals, granary bread, rice and pasta.
Oxiracetam is one of the 3 most popular -racetams; less popular than piracetam but seems to be more popular than aniracetam. Prices have come down substantially since the early 2000s, and stand at around 1.2g/$ or roughly 50 cents a dose, which was low enough to experiment with; key question, does it stack with piracetam or is it redundant for me? (Oxiracetam can’t compete on price with my piracetam pile stockpile: the latter is now a sunk cost and hence free.)
Took pill 12:11 PM. I am not certain. While I do get some things accomplished (a fair amount of work on the Silk Road article and its submission to places), I also have some difficulty reading through a fiction book (Sum) and I seem kind of twitchy and constantly shifting windows. I am weakly inclined to think this is Adderall (say, 60%). It’s not my normal feeling. Next morning - it was Adderall.
Similarly, Mehta et al 2000 noted that the positive effects of methylphenidate (40 mg) on spatial working memory performance were greatest in those volunteers with lower baseline working memory capacity. In a study of the effects of ginkgo biloba in healthy young adults, Stough et al 2001 found improved performance in the Trail-Making Test A only in the half with the lower verbal IQ.
Since the discovery of the effect of nootropics on memory and focus, the number of products on the market has increased exponentially. The ingredients used in a supplement can tell you about the effectiveness of the product. Brain enhancement pills that produce the greatest benefit are formulated with natural vitamins and substances, rather than caffeine and synthetic ingredients. In addition to better results, natural supplements are less likely to produce side effects, compared with drugs formulated with chemical ingredients.
Bacopa Monnieri is probably one of the safest and most effective memory and mood enhancer nootropic available today with the least side-effects. In some humans, a majorly extended use of Bacopa Monnieri can result in nausea. Amongst AlternaScript’s, primary products is Optimind, a nootropic supplement which largely constitutes of Bacopa Monnieri as one of the main ingredients.
Thursday: 3g piracetam/4g choline bitartrate at 1; 1 200mg modafinil at 2:20; noticed a leveling of fatigue by 3:30; dry eyes? no bad after taste or anything. a little light-headed by 4:30, but mentally clear and focused. wonder if light-headedness is due simply to missing lunch and not modafinil. 5:43: noticed my foot jiggling - doesn’t usually jiggle while in piracetam/choline. 7:30: starting feeling a bit jittery & manic - not much or to a problematic level but definitely noticeable; but then, that often happens when I miss lunch & dinner. 12:30: bedtime. Can’t sleep even with 3mg of melatonin! Subjectively, I toss & turn (in part thanks to my cat) until 4:30, when I really wake up. I hang around bed for another hour & then give up & get up. After a shower, I feel fairly normal, strangely, though not as good as if I had truly slept 8 hours. The lesson here is to pay attention to wikipedia when it says the half-life is 12-15 hours! About 6AM I take 200mg; all the way up to 2pm I feel increasingly less energetic and unfocused, though when I do apply myself I think as well as ever. Not fixed by food or tea or piracetam/choline. I want to be up until midnight, so I take half a pill of 100mg and chew it (since I’m not planning on staying up all night and I want it to work relatively soon). From 4-12PM, I notice that today as well my heart rate is elevated; I measure it a few times and it seems to average to ~70BPM, which is higher than normal, but not high enough to concern me. I stay up to midnight fine, take 3mg of melatonin at 12:30, and have no trouble sleeping; I think I fall asleep around 1. Alarm goes off at 6, I get up at 7:15 and take the other 100mg. Only 100mg/half-a-pill because I don’t want to leave the half laying around in the open, and I’m curious whether 100mg + ~5 hours of sleep will be enough after the last 2 days. Maybe next weekend I’ll just go without sleep entirely to see what my limits are.

The use of prescription stimulants is especially prevalent among students.[9] Surveys suggest that 0.7–4.5% of German students have used cognitive enhancers in their lifetime.[10][11][12] Stimulants such as dimethylamylamine and methylphenidate are used on college campuses and by younger groups.[13] Based upon studies of self-reported illicit stimulant use, 5–35% of college students use diverted ADHD stimulants, which are primarily intended for performance enhancement rather than as recreational drugs.[14][15][16] Several factors positively and negatively influence an individual's willingness to use a drug for the purpose of enhancing cognitive performance. Among them are personal characteristics, drug characteristics, and characteristics of the social context.[10][11][17][18]
×