Before you try nootropics, I suggest you start with the basics: get rid of the things in your diet and life that reduce cognitive performance first. That is easiest. Then, add in energizers like Brain Octane and clean up your diet. Then, go for the herbals and the natural nootropics. Use the pharmaceuticals selectively only after you’ve figured out your basics.
A constituent of the turmeric spice, curcumin was first discovered for its brain health benefits when epidemiological studies revealed those in regions with a high consumption of the curry spice turmeric had fewer reported cases of cognitive diseases. It is theorized that the unmatched anti-inflammatory power of curcumin, in combination with its unique antioxidant make-up, inhibits the formation of amyloid build up in the brain.
Caffeine metabolism is primarily determined by the cytochrome enzyme P-450 1A2 (CYP1A2), and studies have shown that different ethnic populations exhibit widely varying expressions of the gene responsible for CYP1A2. Evidence suggests that a particular CYP1A2 impacts caffeine consumption by modifying the risks of certain diseases that are associated with caffeine consumption. It has also been shown that variations in the expression of genes that code for adenosine and dopamine receptors play a role in mediating your response to caffeine. For example, in Caucasians, the presence of certain genetic expressions for both adenosine and dopamine receptors is associated with caffeine-induced anxiety. Variations in CYP1A2 are also responsible for the speed at which different people metabolize caffeine.

[…] The 7 Best Brain Boosting Supplements | Live in the Now … – Act now to protect your brain with exercise, a healthy diet and brain boosting supplements! Share the knowledge! … cells and coffee and tomato sauce as my antioxidants since they are cheap out here. organic fruits and veges are also cheap out here to fruits for 3$ can take me 7days! […]
By analyzing the brain images, the team found that these patients, compared with people who weren’t susceptible to the placebo, had a difference in volume between the right and left sides of the limbic system in the brain, which is involved in instinct and mood. There were also differences in the number of nerve cell connections between the prefrontal cortex and other brain areas. Personality questionnaires revealed that these people had a higher self-awareness and openness than nonresponders.
Thanks to the many years of research in the field, we know now that what we eat can have a strong impact on our mental health. Not only can it protect us from developing Alzheimer's, but it's an act of self-care on its own. "Biology is all about harmony, about finding equilibrium and homeostasis," says Dr. Lisa, which is why her approach differs from food restrictions and focuses on minimizing intake of those foods that don't help us feel better. 
The word “nootropic” was coined in 1972 by a Romanian scientist, Corneliu Giurgea, who combined the Greek words for “mind” and “bending.” Caffeine and nicotine can be considered mild nootropics, while prescription Ritalin, Adderall and Provigil (modafinil, a drug for treating narcolepsy) lie at the far end of the spectrum when prescribed off-label as cognitive enhancers. Even microdosing of LSD is increasingly viewed as a means to greater productivity.

Potassium citrate powder is neither expensive nor cheap: I purchased 453g for $21. The powder is crystalline white, dissolves instantly in water, and largely tasteless (sort of saline & slightly unpleasant). The powder is 37% potassium by weight (the formula is C6H5K3O7) so 453g is actually 167g of potassium, so 80-160 days’ worth depending on dose.

The bitter reality of life is that there’s no organ of our body, which can defy the effects of aging with success. At least not entirely on its own. That’s why we need supplements in the first place. Remember? That’s only the beginning of the bad news for your brain. Certain sections of our brain, especially prefrontal cortex and hippocampus, can be seriously reduced in size as you are getting older. In addition, the number of capillaries in your head reduces, as well. Let’s not forget the arteries that become narrower and therefore limit the blood flow.
However, normally when you hear the term nootropic kicked around, people really mean a “cognitive enhancer” — something that does benefit thinking in some way (improved memory, faster speed-of-processing, increased concentration, or a combination of these, etc.), but might not meet the more rigorous definition above.  “Smart drugs” is another largely-interchangeable term.
For illustration, consider amphetamines, Ritalin, and modafinil, all of which have been proposed as cognitive enhancers of attention. These drugs exhibit some positive effects on cognition, especially among individuals with lower baseline abilities. However, individuals of normal or above-average cognitive ability often show negligible improvements or even decrements in performance following drug treatment (for details, see de Jongh, Bolt, Schermer, & Olivier, 2008). For instance, Randall, Shneerson, and File (2005) found that modafinil improved performance only among individuals with lower IQ, not among those with higher IQ. [See also Finke et al 2010 on visual attention.] Farah, Haimm, Sankoorikal, & Chatterjee 2009 found a similar nonlinear relationship of dose to response for amphetamines in a remote-associates task, with low-performing individuals showing enhanced performance but high-performing individuals showing reduced performance. Such ∩-shaped dose-response curves are quite common (see Cools & Robbins, 2004)
NGF may sound intriguing, but the price is a dealbreaker: at suggested doses of 1-100μg (NGF dosing in humans for benefits is, shall we say, not an exact science), and a cost from sketchy suppliers of $1210/100μg/$470/500μg/$750/1000μg/$1000/1000μg/$1030/1000μg/$235/20μg. (Levi-Montalcini was presumably able to divert some of her lab’s production.) A year’s supply then would be comically expensive: at the lowest doses of 1-10μg using the cheapest sellers (for something one is dumping into one’s eyes?), it could cost anywhere up to $10,000.
Since my experiment had a number of flaws (non-blind, varying doses at varying times of day), I wound up doing a second better experiment using blind standardized smaller doses in the morning. The negative effect was much smaller, but there was still no mood/productivity benefit. Having used up my first batch of potassium citrate in these 2 experiments, I will not be ordering again since it clearly doesn’t work for me.
Eugeroics (armodafinil and modafinil) – are classified as "wakefulness promoting" agents; modafinil increased alertness, particularly in sleep deprived individuals, and was noted to facilitate reasoning and problem solving in non-ADHD youth.[23] In a systematic review of small, preliminary studies where the effects of modafinil were examined, when simple psychometric assessments were considered, modafinil intake appeared to enhance executive function.[27] Modafinil does not produce improvements in mood or motivation in sleep deprived or non-sleep deprived individuals.[28]