(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.)

Here’s how it works: Donepezil boosts serotonin and acetylcholine in the brain, chemicals that are usually found in high concentrations in the brains of young children which naturally decrease with age. As a cholinesterase inhibitor, Donezepil boosts brain function by increasing the amount of acetylcholine around nerve endings. In dementia and Alzheimer’s patients, the drug has been shown to improve memory function.
The nootropics community is surprisingly large and involved. When I wade into forums and the nootropics subreddit, I find members trading stack recipes and notifying each other of newly synthesized compounds. Some of these “psychonauts” seem like they’ve studied neuroscience; others appear to be novices dipping their toes into the world of cognitive enhancement. But all of them have the same goal: amplifying the brain’s existing capabilities without screwing anything up too badly. It’s the same impulse that grips bodybuilders—the feeling that with small chemical tweaks and some training, we can squeeze more utility out of the body parts we have. As Taylor Hatmaker of the Daily Dot recently wrote, “Together, these faceless armchair scientists seek a common truth—a clean, unharmful way to make their brains better—enforcing their own self-imposed safety parameters and painstakingly precise methods, all while publishing their knowledge for free, in plain text, to relatively crude, shared databases."
Vinpocetine: This chemical is a semi-synthetic derivative of an extract from periwinkle.  It acts as a potent anti-inflammatory agent, and has also received some testing as a supplement for memory enhancement.  While research results are inconclusive right now, this chemical has been shown to increase blood circulation and metabolism in the brain and may slow down neuron loss.  Some tests have also shown that it can improve concentration and attention.
I largely ignored this since the discussions were of sub-RDA doses, and my experience has usually been that RDAs are a poor benchmark and frequently far too low (consider the RDA for vitamin D). This time, I checked the actual RDA - and was immediately shocked and sure I was looking at a bad reference: there was no way the RDA for potassium was seriously 3700-4700mg or 4-5 grams daily, was there? Just as an American, that implied that I was getting less than half my RDA. (How would I get 4g of potassium in the first place? Eat a dozen bananas a day⸮) I am not a vegetarian, nor is my diet that fantastic: I figured I was getting some potassium from the ~2 fresh tomatoes I was eating daily, but otherwise my diet was not rich in potassium sources. I have no blood tests demonstrating deficiency, but given the figures, I cannot see how I could not be deficient.
Take at 11 AM; distractions ensue and the Christmas tree-cutting also takes up much of the day. By 7 PM, I am exhausted and in a bad mood. While I don’t expect day-time modafinil to buoy me up, I do expect it to at least buffer me against being tired, and so I conclude placebo this time, and with more confidence than yesterday (65%). I check before bed, and it was placebo.
Qualia claims that its product stems from a new approach to science based on “principled meta-analysis and synthesis of existing research” to optimize “memory, focus, the speed of information processing, and pattern analysis.” The bottom line, however, is in its online medical disclaimer, which says: “These statements have not been evaluated by the Food and Drug Administration. . . . No claims are made about the safety of this product, nor are any medical or psychological benefits claimed.”

Green tea is widely drunk in many cultures, especially in Asia, and is known to have potent health benefits. These benefits are attributed to its polyphenol content (particularly the flavanols and flavonols). In cell cultures and animal studies, the polyphenols have been proven to prevent neurotoxin-induced cell injury. Green tea also has anti-inflammatory properties and, according to a study performed on aged mice, may delay memory regression. It’s safe to drink several cups of green tea per day, though it may be more efficacious to take a green tea extract supplement to reach a daily dose of 400 to 500 mg of EGCG, one of the main active components of green tea.
We felt that the price for this product was OK but were concerned about how cheap it was on some websites. Our experience suggests that this could reflect the standard of the product, it could be that the quality of ingredients is poor and the dosage low so that they can price cut, however, this leaves consumers having to take more to reach the same level as other products. This can lead to all sorts of issues regarding overdosing, so for these reasons, until further testing can be carried out, we could not place this higher on our score board.

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:
Even the best of today’s nootropics only just barely scratch the surface. You might say that we are in the “Nokia 1100” phase of taking nootropics, and as better tools and more data come along, the leading thinkers in the space see a powerful future. For example, they are already beginning to look past biochemistry to the epigenome. Not only is the epigenome the code that runs much of your native biochemistry, we now know that experiences in life can be recorded in your epigenome and then passed onto future generations. There is every reason to believe that you are currently running epigenetic code that you inherited from your great-grandmother’s life experiences. And there is every reason to believe that the epigenome can be hacked – that the nootropics of the future can not only support and enhance our biochemistry, but can permanently change the epigenetic code that drives that biochemistry and that we pass onto our children.
So how do I pull off this stack? It’s quite simple, really. I order 1-milligram nicotine toothpicks on Amazon that I suck on when I’m downing a cup of coffee (the cinnamon flavor blends quite nicely with a cup o’ joe) and I also keep a dispenser of 1.5-milligram nicotine mints in my office. Warning: nicotine can be addictive. I recommend limiting yourself to no more than 1-2 toothpicks and 1-2 mints per day, and only using on more cognitively demanding days. As a bonus, both caffeine and nicotine are potent ergogenic, physical performance-enhancing aids (albeit in higher amounts, closer to 100+ milligrams for caffeine and 2.5+ milligrams for nicotine).
However, anthropology suggests that paleolithic diets were dependent of where people lived. Close to shores, they ate more fish; within the forest they ate plants; in areas with herbivores they ate more meat. Also, humans ate grains millions of years before the agricultural revolution. And, we can digest those just fine because of an enzyme earmarked to digest grains (amylase). So, paleolithic diets were as varied as they are today.
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.)
But notice that most of the cost imbalance is coming from the estimate of the benefit of IQ - if it quadrupled to a defensible $8000, that would be close to the experiment cost! So in a way, what this VoI calculation tells us is that what is most valuable right now is not that iodine might possibly increase IQ, but getting a better grip on how much any IQ intervention is worth.
Caffeine keeps you awake, which keeps you coding. It may also be a nootropic, increasing brain-power. Both desirable results. However, it also inhibits vitamin D receptors, and as such decreases the body’s uptake of this-much-needed-vitamin. OK, that’s not so bad, you’re not getting the maximum dose of vitamin D. So what? Well, by itself caffeine may not cause you any problems, but combined with cutting off a major source of the vitamin - the production via sunlight - you’re leaving yourself open to deficiency in double-quick time.
A fancier method of imputation would be multiple imputation using, for example, the R library mice (Multivariate Imputation by Chained Equations) (guide), which will try to impute all missing values in a way which mimicks the internal structure of the data and provide several possible datasets to give us an idea of what the underlying data might have looked like, so we can see how our estimates improve with no missingness & how much of the estimate is now due to the imputation:
I took the first pill at 12:48 pm. 1:18, still nothing really - head is a little foggy if anything. later noticed a steady sort of mental energy lasting for hours (got a good deal of reading and programming done) until my midnight walk, when I still felt alert, and had trouble sleeping. (Zeo reported a ZQ of 100, but a full 18 minutes awake, 2 or 3 times the usual amount.)
Analgesics Anesthetics General Local Anorectics Anti-ADHD agents Antiaddictives Anticonvulsants Antidementia agents Antidepressants Antimigraine agents Antiparkinson agents Antipsychotics Anxiolytics Depressants Entactogens Entheogens Euphoriants Hallucinogens Psychedelics Dissociatives Deliriants Hypnotics/Sedatives Mood Stabilizers Neuroprotectives Nootropics Neurotoxins Orexigenics Serenics Stimulants Wakefulness-promoting agents
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