The desire to improve cognitive functioning has probably existed since the dawn of human consciousness. Throughout our evolution, increased mental agility has been associated with fitness and improved odds of survival and success. Although concoctions to stimulate brainpower have existed in Chinese and Indian medicine for hundreds of years, Western nootropics were not developed until 1964.

Much of what she says is standard health advice. Avoid trans fats. Eat fresh vegetables and fruit. Avoid processed foods. Limit red meat consumption. It’s better to get your nutrients from food than from supplement pills. Exercise, get adequate sleep, and avoid stress. Since the brain runs on glucose, she wouldn’t agree with the low-carb diet folks; she says we need adequate sources of glucose in our diet, and recommends complex carbs, paying attention to the glycemic index.

The amphetamine mix branded Adderall is terribly expensive to obtain even compared to modafinil, due to its tight regulation (a lower schedule than modafinil), popularity in college as a study drug, and reportedly moves by its manufacture to exploit its privileged position as a licensed amphetamine maker to extract more consumer surplus. I paid roughly $4 a pill but could have paid up to $10. Good stimulant hygiene involves recovery periods to avoid one’s body adapting to eliminate the stimulating effects, so even if Adderall was the answer to all my woes, I would not be using it more than 2 or 3 times a week. Assuming 50 uses a year (for specific projects, let’s say, and not ordinary aimless usage), that’s a cool $200 a year. My general belief was that Adderall would be too much of a stimulant for me, as I am amphetamine-naive and Adderall has a bad reputation for letting one waste time on unimportant things. We could say my prediction was 50% that Adderall would be useful and worth investigating further. The experiment was pretty simple: blind randomized pills, 10 placebo & 10 active. I took notes on how productive I was and the next day guessed whether it was placebo or Adderall before breaking the seal and finding out. I didn’t do any formal statistics for it, much less a power calculation, so let’s try to be conservative by penalizing the information quality heavily and assume it had 25%. So \frac{200 - 0}{\ln 1.05} \times 0.50 \times 0.25 = 512! The experiment probably used up no more than an hour or two total.
The original magnesium l-threonate caused me no apparent problems by the time I finished off the powder and usage correlated with better days, further supporting the hypothesis that magnesium helps it. But l-threonate would be difficult to cap (and hence blind self-experiment) and is ruinously expensive on a per-dose basis. So I looked around for alternatives for the followup; one of the most common compounds suggested was the citrate form because it is reasonably well-absorbed and causes fewer digestive problems, so I could just take that. Magnesium oxide is widely available it looks cheap, but the absorption/bioavailability problem makes it unattractive: at a 3:5 ratio, an estimate of 4% absorption, a ZMA formulation of an impressive-sounding 500mg would be 500 \times \frac{3}{5} \times 0.04 = 12mg or a small fraction of RDAs for male adults like 400mg elemental. (Calcium shouldn’t be a problem since I get 220mg of calcium from my multivitamin and I enjoy dairy products daily.)
The nootropics I’m taking are called RISE, and they're made by a company called Nootrobox, which was started by Geoffrey Woo, a young Stanford computer science graduate. There's no one common ingredient in nootropics; what unites them is the intent to improve brain performance. The RISE stack, which costs $29 plus shipping for 30 pills, contains 350 mg of bacopa monnieri powder (an herb that is commonly used medicinally in South Asia), 100 mg of L-theanine (an amino acid found in green tea), and 50 mg of caffeine (about the amount in a can of Diet Coke). Like most nootropics, the RISE stack itself isn't FDA-approved for use as a cognitive enhancer, but Nootrobox says that the compounds within it are approved as dietary supplements. "We use the precise ingredients at the right dosages and the right ratios as supported by double-blind, peer-reviewed clinicals," Nootrobox's site claims.
Finding a usable product on Amazon caused me some difficulties. I wanted a 500mg magnesium-citrate-only product at <$20 for 120 doses, but I discovered most of the selection for magnesium citrate had sub-500mg doses, involved calcium citrate or other substances like zinc (not necessarily a bad thing, but would confound an experiment), were mostly magnesium oxide rather than citrate, or some still other problem. Ultimately I settled on Solgar’s $13 120x400mg magnesium citrate as acceptable. (To compare with the bulkiness of the LEF vitamin D+l-threonate powder, the Office of Dietary Supplements says magnesium citrate is 16% magnesium, so to get 400mg of magnesium as claimed, would take 2.5g of material, rather than 7g for 200mg; even if l-threonate is absorbed 100% and citrate 50%, the citrate is ahead. The pills turn out to be wider and longer than my 00 pills; if I want to get them into my gel capsules, I have to crush them into fine powder. The powder from one pill turns out to take up 2 00 pills.)
B vitamins are also sold with claims of enhancing memory, usually rationalized by their reduction of homocysteine, a chemical in the blood that may affect circulation in the brain. No benefits from B vitamin intake have been demonstrated when it comes to memory or cognitive function except in the case of people who have high homocysteine levels due to a diet that is very low in B vitamins. There is some concern that folic acid, one of the B vitamins, may spur the growth of polyps in the colon at doses greater than 800 micrograms a day. Phosphatidyl serine is a natural component of nerve cell membranes and its promoters argue that a deficiency leads to impaired communication between nerve cells which in turn impairs cognitive function. Sounds reasonable, except that proper controlled trials have come up empty. The same goes for vinpocetine, a compound originally isolated from the lesser periwinkle plant by Hungarian chemist Csaba Szantay in 1975. It is widely used in Europe to treat strokes and memory problems with claims of increased circulation to the brain. It does indeed increase circulation, much like ginkgo, but there is no compelling evidence for memory improvement.
After many years recruiting teens from across the city to join us for a year of culinary adventures, we’re relying on the city’s network of talented youth service providers to fill the gap and cultivate the next generation of smart, resilient youth leaders. While this isn’t where we wanted to be, we’re reaching for gratitude and sharing KUDOS one last time.
Difficulty concentrating.  As mentioned previously, this may not be a direct result of age—though it can be a common side-effect of struggling with fatigue and brain fog.  When it takes more mental energy to think, it is harder to stay with it for a long time.  Many of us also are surrounded by distractions clambering for our limited attention.  Modern life is fast-paced, stressful, and overcrowded.
According to the US Food and Drug Administration, "Piracetam is not a vitamin, mineral, amino acid, herb or other botanical, or dietary substance for use by man to supplement the diet by increasing the total dietary intake. Further, piracetam is not a concentrate, metabolite, constituent, extract or combination of any such dietary ingredient. [...] Accordingly, these products are drugs, under section 201(g)(1)(C) of the Act, 21 U.S.C. § 321(g)(1)(C), because they are not foods and they are intended to affect the structure or any function of the body. Moreover, these products are new drugs as defined by section 201(p) of the Act, 21 U.S.C. § 321(p), because they are not generally recognized as safe and effective for use under the conditions prescribed, recommended, or suggested in their labeling."[33]