Brain focus pills largely contain chemical components like L-theanine which is naturally found in green and black tea. It’s associated with enhancing alertness, cognition, relaxation, arousal, and reducing anxiety to a large extent.  Theanine is an amino and glutamic acid that has been proven to be a safe psychoactive substance. There are studies that suggest that this compound influences, the expression in the genes present in the brain which is responsible for aggression, fear and memory. This, in turn, helps in balancing the behavioural responses to stress and also helps in improving specific conditions, like Post Traumatic Stress Disorder (PTSD).
Looking at the prices, the overwhelming expense is for modafinil. It’s a powerful stimulant - possibly the single most effective ingredient in the list - but dang expensive. Worse, there’s anecdotal evidence that one can develop tolerance to modafinil, so we might be wasting a great deal of money on it. (And for me, modafinil isn’t even very useful in the daytime: I can’t even notice it.) If we drop it, the cost drops by a full $800 from $1761 to $961 (almost halving) and to $0.96 per day. A remarkable difference, and if one were genetically insensitive to modafinil, one would definitely want to remove it.
The principal metric would be mood, however defined. Zeo’s web interface & data export includes a field for Day Feel, which is a rating 1-5 of general mood & quality of day. I can record a similar metric at the end of each day. 1-5 might be a little crude even with a year of data, so a more sophisticated measure might be in order. The first mood study is paywalled so I’m not sure what they used, but Shiotsuki 2008 used State-Trait of Anxiety Inventory (STAI) and Profiles of Mood States Test (POMS). The full POMS sounds too long to use daily, but the Brief POMS might work. In the original 1987 paper A brief POMS measure of distress for cancer patients, patients answering this questionnaire had a mean total mean of 10.43 (standard deviation 8.87). Is this the best way to measure mood? I’ve asked Seth Roberts; he suggested using a 0-100 scale, but personally, there’s no way I can assess my mood on 0-100. My mood is sufficiently stable (to me) that 0-5 is asking a bit much, even.
“It is surprising and encouraging that it may be possible to predict the magnitude of a placebo effect before treatment,” says Tor Wager, a neuroscientist at the University of Colorado Boulder, who was not involved in the research. More work is needed to see how the predictive features hold up in other populations and for different pain conditions, he says.
As with any thesis, there are exceptions to this general practice. For example, theanine for dogs is sold under the brand Anxitane is sold at almost a dollar a pill, and apparently a month’s supply costs $50+ vs $13 for human-branded theanine; on the other hand, this thesis predicts downgrading if the market priced pet versions higher than human versions, and that Reddit poster appears to be doing just that with her dog.↩
Still, even if you acknowledge that cosmetic neurology is here to stay, there is something dispiriting about the way the drugs are used - the kind of aspirations they open up, or don't. Jonathan Eisen, an evolutionary biologist at the University of California, Davis, is sceptical of what he mockingly calls "brain doping". During a recent conversation, he spoke about colleagues who take neuroenhancers in order to grind out grant proposals. "It's weird to me that people are taking these drugs to write grants," he said. "I mean, if you came up with some really interesting paper that was spurred by taking some really interesting drug - magic mushrooms or something - that would make more sense to me. In the end you're only as good as the ideas you've come up with."

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.
In the study, which evaluated the eating habits and mental ability of more than 950 older adults for an average of five years, those adults who ate a serving of leafy green veggies once or twice a day experienced slower mental deterioration than those who ate no vegetables, even when factors like age, education and family history of dementia were factored in.
For this batch, I tried out NOW Foods Magnesium Citrate Powder ($7 for 227g); the powder was still a bit sticky but much easier to work with than the Solgar pills, and the 227g made 249 gel capsule pills. The package estimates 119 serving of 315mg elemental magnesium, so a ratio of 0.315g magnesium for 1.9g magnesium citrate, implying that each gel cap pill then contains 0.152g magnesium (\frac{(119\times315)}{249}=150) and since I want a total dose of 0.8g, I need 5 of the gel cap pills a day or 35 per block.
One thing I did do was piggyback on my Noopept self-experiment: I blinded & randomized the Noopept for a real experiment, but simply made sure to vary the Magtein without worrying about blinding or randomizing it. (The powder is quite bulky.) The correlation the experiment turned in was a odds-ratio of 1.9; interesting and in the right direction (higher is better), but since the magnesium part wasn’t random or blind, not a causal result.

Seriously. Every single thing you experience comes through your brain. It create the fabric of your reality, and by the same token, the energy your brain makes is what allows you to shape that reality. Work, relationships, success, happiness — everything depends on your brain, and building a stronger one will trigger upgrades that extend across every aspect of your life.
It seems like we're constantly bombarded by the newest superfoods, how matcha is the coffee, and why Himalayan salt is "so much better" than sea salt (spoiler alert: it's not, but its pink hue definitely makes cooking more fun). Dieting has always been an on/off kind of activity in my life which is why I've struggled to jump on this train for a while.

The demands of university studies, career, and family responsibilities leaves people feeling stretched to the limit. Extreme stress actually interferes with optimal memory, focus, and performance. The discovery of nootropics and vitamins that make you smarter has provided a solution to help college students perform better in their classes and professionals become more productive and efficient at work.

In addition to diet, there are many other things you can also do related to lifestyle, such as stress management through mindfulness (8) or gentle movement such as pre or post natal yoga (9), which have both shown to be incredibly helpful in encouraging mental wellbeing. If you feel you need extra support, personalised nutritional therapy can be very helpful as there can often be other drivers such as nutrient deficiencies and digestive complaints that can play a significant role in mental health and will need to be addressed in a way that is tailored to the individual. 

“Who doesn’t want to maximize their cognitive ability? Who doesn’t want to maximize their muscle mass?” asks Murali Doraiswamy, who has led several trials of cognitive enhancers at Duke University Health System and has been an adviser to pharmaceutical and supplement manufacturers as well as the Food and Drug Administration. He attributes the demand to an increasingly knowledge-based society that values mental quickness and agility above all else.
Large scale studies have shown the association between chronic low-grade inflammation and depression (8). For example, in a study that examined data from 14,275 people who were interviewed between 2007 and 2012, they found that people who had depression had 46% higher levels of C-reactive protein (CRP), a marker of inflammatory disease, in their blood samples (9). Studies like these are paving the way towards a new understanding of the pathology of mental health conditions and how diet and stress can alter bodily systems, such as digestive function and consequently impact mental wellbeing. Measuring IgG antibodies in food intolerance tests has been implicated as a popular strategy to tackle symptoms related to sensitivities such as IBS, joint pain, fatigue, migraines, anxiety and depression. A recent survey on 708 people commissioned by Allergy UK, demonstrated how 81% of those with elevated IgG levels, as well as psychological symptoms, reported an improvement in their condition after following a food-specific IgG elimination diet (9). Taking this all into account, health professionals and those with poor mental health may want to consider the potential role of food intolerances in mental well-being and in managing common mood-related disorders, such as depression and anxiety.

For starters, it’s one of the highest antioxidant-rich foods known to man, including vitamin C and vitamin K and fiber. Because of their high levels of gallic acid, blueberries are especially good at protecting our brains from degeneration and stress. Get your daily dose of brain berries in an Omega Blueberry Smoothie, Pumpkin Blueberry Pancakes or in a Healthy Blueberry Cobbler.
We can read off the results from the table or graph: the nicotine days average 1.1% higher, for an effect size of 0.24; however, the 95% credible interval (equivalent of confidence interval) goes all the way from 0.93 to -0.44, so we cannot exclude 0 effect and certainly not claim confidence the effect size must be >0.1. Specifically, the analysis gives a 66% chance that the effect size is >0.1. (One might wonder if any increase is due purely to a training effect - getting better at DNB. Probably not26.)
It seems like we're constantly bombarded by the newest superfoods, how matcha is the coffee, and why Himalayan salt is "so much better" than sea salt (spoiler alert: it's not, but its pink hue definitely makes cooking more fun). Dieting has always been an on/off kind of activity in my life which is why I've struggled to jump on this train for a while.
My answer is that this is not a lot of research or very good research (not nearly as good as the research on nicotine, eg.), and assuming it’s true, I don’t value long-term memory that much because LTM is something that is easily assisted or replaced (personal archives, and spaced repetition). For me, my problems tend to be more about akrasia and energy and not getting things done, so even if a stimulant comes with a little cost to long-term memory, it’s still useful for me. I’m going continue to use the caffeine. It’s not so bad in conjunction with tea, is very cheap, and I’m already addicted, so why not? Caffeine is extremely cheap, addictive, has minimal effects on health (and may be beneficial, from the various epidemiological associations with tea/coffee/chocolate & longevity), and costs extra to remove from drinks popular regardless of their caffeine content (coffee and tea again). What would be the point of carefully investigating it? Suppose there was conclusive evidence on the topic, the value of this evidence to me would be roughly $0 or since ignorance is bliss, negative money - because unless the negative effects were drastic (which current studies rule out, although tea has other issues like fluoride or metal contents), I would not change anything about my life. Why? I enjoy my tea too much. My usual tea seller doesn’t even have decaffeinated oolong in general, much less various varieties I might want to drink, apparently because de-caffeinating is so expensive it’s not worthwhile. What am I supposed to do, give up my tea and caffeine just to save on the cost of caffeine? Buy de-caffeinating machines (which I couldn’t even find any prices for, googling)? This also holds true for people who drink coffee or caffeinated soda. (As opposed to a drug like modafinil which is expensive, and so the value of a definitive answer is substantial and would justify some more extensive calculating of cost-benefit.)

Jump up ^ Weyandt LL, Oster DR, Marraccini ME, Gudmundsdottir BG, Munro BA, Zavras BM, Kuhar B (September 2014). "Pharmacological interventions for adolescents and adults with ADHD: stimulant and nonstimulant medications and misuse of prescription stimulants". Psychol. Res. Behav. Manag. 7: 223–249. doi:10.2147/PRBM.S47013. PMC 4164338. PMID 25228824.