I was contacted by the Longecity user lostfalco, and read through some of his writings on the topic. I had never heard of LLLT before, but the mitochondria mechanism didn’t sound impossible (although I wondered whether it made sense at a quantity level14151617), and there was at least some research backing it; more importantly, lostfalco had discovered that devices for LLLT could be obtained as cheap as $15. (Clearly no one will be getting rich off LLLT or affiliate revenue any time soon.) Nor could I think of any way the LLLT could be easily harmful: there were no drugs involved, physical contact was unnecessary, power output was too low to directly damage through heating, and if it had no LLLT-style effect but some sort of circadian effect through hitting photoreceptors, using it in the morning wouldn’t seem to interfere with sleep.
While the mechanism is largely unknown, one commonly mechanism possibility is that light of the relevant wavelengths is preferentially absorbed by the protein cytochrome c oxidase, which is a key protein in mitochondrial metabolism and production of ATP, substantially increasing output, and this extra output presumably can be useful for cellular activities like healing or higher performance.

And many people swear by them. Neal Thakkar, for example, is an entrepreneur from Marlboro, New Jersey, who claims nootropics improved his life so profoundly that he can’t imagine living without them. His first breakthrough came about five years ago, when he tried a piracetam/choline combination, or “stack,” and was amazed by his increased verbal fluency. (Piracetam is a cognitive-enhancement drug permitted for sale in the U. S. as a dietary supplement; choline is a natural substance.)
According to the official website, Cognizin is based on Citicoline, which is a highly beneficial nutrient that’s useful for assisting certain brain functions that are related to mental focus and cognitive processing. What’s more, it’s shown to improve your brain’s metabolism regarding the use of acetylcholine, which is an important neurotransmitter involved in the storage and processing of memory.
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.
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Piracetam is well studied and is credited by its users with boosting their memory, sharpening their focus, heightening their immune system, even bettering their personalities. But it’s only one of many formulations in the racetam drug family. Newer ones include aniracetam, phenylpiracetam and oxiracetam. All are available online, where their efficacy and safety are debated and reviewed on message boards and in podcasts.
Bought 5,000 IU soft-gels of Vitamin D-334 (Examine.com; FDA adverse events) because I was feeling very apathetic in January 2011 and not getting much done, even slacking on regular habits like Mnemosyne spaced repetition review or dual n-back or my Wikipedia watchlist. Introspecting, I was reminded of depression & dysthymia & seasonal affective disorder.
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).
Now, what is the expected value (EV) of simply taking iodine, without the additional work of the experiment? 4 cans of 0.15mg x 200 is $20 for 2.1 years’ worth or ~$10 a year or a NPV cost of $205 (\frac{10}{\ln 1.05}) versus a 20% chance of $2000 or $400. So the expected value is greater than the NPV cost of taking it, so I should start taking iodine.
My predictions were substantially better than random chance7, so my default belief - that Adderall does affect me and (mostly) for the better - is borne out. I usually sleep very well and 3 separate incidents of horrible sleep in a few weeks seems rather unlikely (though I didn’t keep track of dates carefully enough to link the Zeo data with the Adderall data). Between the price and the sleep disturbances, I don’t think Adderall is personally worthwhile.

I’m wary of others, though. The trouble with using a blanket term like “nootropics” is that you lump all kinds of substances in together. Technically, you could argue that caffeine and cocaine are both nootropics, but they’re hardly equal. With so many ways to enhance your brain function, many of which have significant risks, it’s most valuable to look at nootropics on a case-by-case basis. Here’s a list of 13 nootropics, along with my thoughts on each.

Paul Phillips was unusual for a professional poker player. When he joined the circuit in the late 1990s he was already a millionaire: a twentysomething tech guy who helped found an internet portal called go2net and cashed in at the right moment. He was cerebral and at times brusque. On the international poker scene Phillips cultivated a geeky New Wave style. He wore vintage shirts in wild geometric patterns; his hair was dyed orange or silver one week, shaved off the next. Most unusual of all, Phillips talked freely about taking prescription drugs - Adderall and, especially, Provigil - in order to play better cards.

Recently I spoke on the phone with Barbara Sahakian, a clinical neuropsychologist at Cambridge University and the co-author of a 2007 article in Nature entitled "Professor's Little Helper". Sahakian, who also consults for several pharmaceutical companies, and her co-author, Sharon Morein-Zamir, reported that a number of their colleagues were using prescription drugs like Adderall and Provigil. Because the drugs are easy to buy online, they wrote, it would be difficult to stop their spread: "The drive for self-enhancement of cognition is likely to be as strong if not stronger than in the realms of 'enhancement' of beauty and sexual function." (In places like Cambridge, at least.)

Nootropics (/noʊ.əˈtrɒpɪks/ noh-ə-TROP-iks) (colloquial: smart drugs and cognitive enhancers) are drugs, supplements, and other substances that may improve cognitive function, particularly executive functions, memory, creativity, or motivation, in healthy individuals.[1] While many substances are purported to improve cognition, research is at a preliminary stage as of 2018, and the effects of the majority of these agents are not fully determined.