Your mileage will vary. There are so many parameters and interactions in the brain that any of them could be the bottleneck or responsible pathway, and one could fall prey to the common U-shaped dose-response curve (eg. Yerkes-Dodson law; see also Chemistry of the adaptive mind & de Jongh et al 2007) which may imply that the smartest are those who benefit least23 but ultimately they all cash out in a very few subjective assessments like energetic or motivated, with even apparently precise descriptions like working memory or verbal fluency not telling you much about what the nootropic actually did. It’s tempting to list the nootropics that worked for you and tell everyone to go use them, but that is merely generalizing from one example (and the more nootropics - or meditation styles, or self-help books, or getting things done systems - you try, the stronger the temptation is to evangelize). The best you can do is read all the testimonials and studies and use that to prioritize your list of nootropics to try. You don’t know in advance which ones will pay off and which will be wasted. You can’t know in advance. And wasted some must be; to coin a Umeshism: if all your experiments work, you’re just fooling yourself. (And the corollary - if someone else’s experiments always work, they’re not telling you everything.)
…Phenethylamine is intrinsically a stimulant, although it doesn’t last long enough to express this property. In other words, it is rapidly and completely destroyed in the human body. It is only when a number of substituent groups are placed here or there on the molecule that this metabolic fate is avoided and pharmacological activity becomes apparent.
A large review published in 2011 found that the drug aids with the type of memory that allows us to explicitly remember past events (called long-term conscious memory), as opposed to the type that helps us remember how to do things like riding a bicycle without thinking about it (known as procedural or implicit memory.) The evidence is mixed on its effect on other types of executive function, such as planning or ability on fluency tests, which measure a person’s ability to generate sets of data—for example, words that begin with the same letter. 
Cognizin– this is a derivative of citicoline. It increases* the levels of acetylcholine neurotransmitters, dopamine, and noradrenaline in the brain. These are neurotransmitters essential for brain functioning. Besides this, Cognizin maintains the functioning and stamina of neuronal cell membranes and enhance* energy production from the frontal cortex. With this, you will have increased mental reaction time, expanded focusing ability, improved* immediate and short-term verbal memory and augment the brain’s metabolism.

Attention Deficit and Hyperactivity Disorder (ADHD) is a condition that relates to a collection of behavioural symptoms such as hyperactivity, impulsiveness and inattentiveness. It is most commonly diagnosed in childhood between the ages of 6 and 12 when disruptive behaviour begins to show, however, due to a growing awareness of the condition, it is also becoming common among adults. According to the thinktank Demos, the cost of undiagnosed ADHD in adults in the UK who are unable to work or hold down a full-time job are estimated to cost billions of pounds to the nation. They warn that too many may be going through life struggling, unable to access the support ot diagnosis they need, which means there could be a huge amount of wasted talent.
As a result of her years of research in this area, Dr. Lisa proposes a variety of foods that lead to better cognitive functioning and those which, in contrast, minimize cognitive functioning. "The best four foods one can consume to boost brain power are fish, dark leafy green veggies, berries, and water," she explains. And the worst? "Fast food, processed foods and poor quality meat." 
I eventually met Seltzer in an underground food court not far from the Pentagon. He's slim, with a shaved head, and he spoke precisely, rarely stumbling over his words. I asked him if he had any ethical worries about smart drugs. After a pause, he said that he might have a concern if somebody popped a neuroenhancer before taking a licensing exam that certified him as, say, a brain surgeon, and then stopped using the drug. Other than that he couldn't see a problem. He said that he was a firm believer in the idea that "we should have a fair degree of liberty to do with our bodies and our minds as we see fit, so long as it doesn't impinge on the basic rights, liberty and safety of others". He argued: "Why would you want an upward limit on the intellectual capabilities of a human being? And, if you have a very nationalist viewpoint, why wouldn't you want our country to have the advantage over other countries, particularly in what some people call a knowledge-based economy?" He went on: "Think about the complexity of the intellectual tasks that people need to accomplish today. Just trying to understand what Congress is doing is not a simple thing! The complexity of understanding the gamut of scientific and technical and social issues is difficult. If we had a tool that enabled more people to understand the world at a greater level of sophistication, how can we prejudice ourselves against the notion simply because we don't like athletes to do it? To me it doesn't seem like the same question. And it deserves its own debate."
Of course learning, working memory and cognitive control represent just a few aspects of thinking. Farah concluded that studies looking at other kinds of cognition - verbal fluency, for instance - were too few and too contradictory to tell us much. Both Chatterjee and Farah have wondered whether drugs that heighten users' focus might dampen their creativity. After all, some of our best ideas come to us not when we sit down at a desk but rather when we're in the shower or walking the dog - letting our minds roam. Jimi Hendrix reported that the inspiration for "Purple Haze" came to him in a dream; the chemist Friedrich August Kekule claimed that he discovered the ring structure of benzene during a reverie in which he saw the image of a snake biting its tail. Farah told me: "There is some evidence that suggests that individuals who are better able to focus on one thing and filter out distractions tend to be less creative.
Dr. Lisa Mosconi, PhD, INHC, is the associate director of the Alzheimer's Prevention Clinic at Weill Cornell Medical College (WCMC)/NewYork-Presbyterian Hospital, where she was recruited as an associate professor of Neuroscience in Neurology. She also is an adjunct faculty member in the Department of Psychiatry at NYU School of Medicine, in the Department of Nutrition at NYU Steinhardt School of Nutrition and Public Health, and in the Departments of Neurology and Nuclear Medicine at the University of Florence (Italy). Formerly, Dr. Mosconi founded and was the director of the Nutrition & Brain Fitness Lab at New York University School of Medicine (NYU), and an assistant professor in the NYU Department of Psychiatry, where she served as the director of the Family History of Alzheimer's disease research program. Dr. Mosconi holds a dual PhD degree in Neuroscience and Nuclear Medicine from the University of Florence, Italy, and is a board certified integrative nutritionist and holistic healthcare practitioner. She is well known for her research on the early detection of Alzheimer's disease and is passionately interested in the mitigation and prevention of memory loss through lifestyle modifications including diet, nutrition, and physical and intellectual fitness.
-Raw cacao is rich in theobromine, a powerful antioxidant known to support cellular aging and reduce the risk of heart disease. Its effects are similar to those of caffeine, as they both are vasodilators and improve blood flow to the brain [except cacao won’t give you jitters]...You can use raw cacao to make cacao tea, or in your smoothies. Dark chocolate with cocoa content of 80% or higher is also rich in theobromine and natural antioxidants. Besides, chocolate makes you happy. I have a small piece of high-quality dark chocolate, like 85% or 90% dark, every day.
By the way, before we move on, allow me to clarify what I mean by “slow caffeine metabolizer”. Ever wondered why your co-worker can slam four giant mugs of coffee during a brief morning of work, while one shot of espresso leaves you jittery and irritated? Turns out that not everyone metabolizes caffeine the same. Generally speaking, in healthy adults, caffeine has a half-life that ranges from about 3 to 7 hours. For example, if the half-life of caffeine in your blood is 5 hours, that means that it takes 5 hours for caffeine levels to be reduced by 50%. Then it takes another 5 hours for that amount to be reduced by 50%. While caffeine metabolism time also depends upon age and environmental factors, a big influence on varying caffeine half-life times is your genetic makeup.

One thing I notice looking at the data is that the red magnesium-free days seem to dominate the upper ranks towards the end, and blues appear mostly at the bottom, although this is a little hard to see because good days in general start to become sparse towards the end. Now, why would days start to be worse towards the end, and magnesium-dose days in particular? The grim surmise is: an accumulating overdose - no immediate acute effect, but the magnesium builds up, dragging down all days, but especially magnesium-dose days. The generally recognized symptoms of hypermagnesemia don’t include effect on mood or cognition, aside from muscle weakness, confusion, and decreased reflexes…poor appetite that does not improve, but it seems plausible that below medically-recognizable levels of distress like hypermagnesemia might still cause mental changes, and I wouldn’t expect any psychological research to have been done on this topic.
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.

And when it comes to your brain, it’s full of benefits, too. Coconut oil works as a natural anti-inflammatory, suppressing cells responsible for inflammation. It can help with memory loss as you age and destroy bad bacteria that hangs out in your gut. (5) Get your dose of coconut oil in this Baked Grouper with Coconut Cilantro Sauce or Coconut Crust Pizza.
For the moment, people looking for that particular quick fix have a limited choice of meds. But given the amount of money and research hours being spent on developing drugs to treat cognitive decline, Provigil and Adderall are likely to be joined by a bigger pharmacopoeia. Among the drugs in the pipeline are ampakines, which target a type of glutamate receptor in the brain; it is hoped that they may stem the memory loss associated with diseases like Alzheimer's. But ampakines may also give healthy people a palpable cognitive boost. A 2007 study of 16 healthy elderly volunteers found that 500mg of one particular ampakine "unequivocally" improved short-term memory, though it appeared to detract from episodic memory - the recall of past events. Another class of drugs, cholinesterase inhibitors, which are already being used with some success to treat Alzheimer's patients, have also shown promise as neuroenhancers. In one study the drug donepezil strengthened the performance of pilots on flight simulators; in another, of 30 healthy young male volunteers, it improved verbal and visual episodic memory. Several pharmaceutical companies are working on drugs that target nicotine receptors in the brain in the hope that they can replicate the cognitive uptick that smokers get from cigarettes.
To thwart the rise of non-prescription nootropics, opponents may rally for increased regulation; however, at present, there is insufficient research available to support that non-prescription nootropics pose a danger to public health. Prescription nootropics, such as Ritalin, are already regulated. Further, these drugs have a proven beneficial treatment purpose for intended users.
Our 2nd choice for a Brain and Memory supplement is Clari-T by Life Seasons. We were pleased to see that their formula included 3 of the 5 necessary ingredients Huperzine A, Phosphatidylserine and Bacopin. In addition, we liked that their product came in a vegetable capsule. The product contains silica and rice bran, though, which we are not sure is necessary.
Creatine is a substance that’s produced in the human body. It is initially produced in the kidneys, and the process is completed in the liver. It is then stored in the brain tissues and muscles, to support the energy demands of a human body. Athletes and bodybuilders take creatine supplements for relieving fatigue and increasing the recovery of the muscle tissues that are affected by vigorous physical activities. Apart from helping the tissues to recover faster, creatine also helps in enhancing the mental functions in sleep-deprived adults and it also improves the performance of difficult cognitive tasks.
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."

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.

Panax ginseng – A review by the Cochrane Collaboration concluded that "there is a lack of convincing evidence to show a cognitive enhancing effect of Panax ginseng in healthy participants and no high quality evidence about its efficacy in patients with dementia."[36] According to the National Center for Complementary and Integrative Health, "[a]lthough Asian ginseng has been widely studied for a variety of uses, research results to date do not conclusively support health claims associated with the herb."[37]