Alex was eager to dispel the notion that students who took Adderall were "academic automatons who are using it in order to be first in their class". In fact, he said, "it's often people" - mainly guys - "who are looking in some way to compensate for activities that are detrimental to their performance". He explained, "At Harvard, at the most basic level, they aim to do better than they would have otherwise. Everyone is aware that if you were up at 3am writing this paper it isn't going to be as good as it could have been. The fact that you were partying all weekend, or spent the last week being high, watching Lost - that's going to take a toll."
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.
One of the other suggested benefits is for boosting serotonin levels; low levels of serotonin are implicated in a number of issues like depression. I’m not yet sure whether tryptophan has helped with motivation or happiness. Trial and error has taught me that it’s a bad idea to take tryptophan in the morning or afternoon, however, even smaller quantities like 0.25g. Like melatonin, the dose-response curve is a U: ~1g is great and induces multiple vivid dreams for me, but ~1.5g leads to an awful night and a headache the next day that was worse, if anything, than melatonin. (One morning I woke up with traces of at least 7 dreams, although I managed to write down only 2. No lucid dreams, though.)

Unlike many hypothetical scenarios that bioethicists worry about - human clones, "designer babies" - cognitive enhancement is already in full swing. But how much do they actually help? Are they potentially harmful or addictive? Then there's the question of what we mean by "smarter". Could enhancing one kind of thinking exact a toll on others? All these questions need proper scientific answers, but for now much of the discussion is taking place furtively, among the increasing number of people who are performing daily experiments on their own brains.
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.
Many people quickly become overwhelmed by the volume of information and number of products on the market. Because each website claims its product is the best and most effective, it is easy to feel confused and unable to decide. Smart Pill Guide is a resource for reliable information and independent reviews of various supplements for brain enhancement.
She speaks from professional and personal experience. When she first moved to the United States from Italy at age 24 she was struck by how shifting from the Mediterranean-style diet she grew up on to a standard American diet negatively impacted her physical health and work performance. The experience led her to more closely study nutrition and the link between diet and brain health. In this excerpt from a longer interview, she discusses the brain foods you should be eating.

Alex remains enthusiastic about Adderall, but he also has a slightly jaundiced critique of it. "It only works as a cognitive enhancer insofar as you are dedicated to accomplishing the task at hand," he said. "The number of times I've taken Adderall late at night and decided that, rather than starting my paper, hey, I'll organise my entire music library! I've seen people obsessively cleaning their rooms on it." Alex thought that generally the drug helped him to bear down on his work, but it also tended to produce writing with a characteristic flaw. "Often I've looked back at papers I've written on Adderall, and they're verbose. They're labouring a point, trying to create this airtight argument. I'd produce two pages on something that could be said in a couple of sentences." Nevertheless, his Adderall-assisted papers usually earned him at least a B. They got the job done. As Alex put it: "Productivity is a good thing."
I do recommend a few things, like modafinil or melatonin, to many adults, albeit with misgivings about any attempt to generalize like that. (It’s also often a good idea to get powders, see the appendix.) Some of those people are helped; some have told me that they tried and the suggestion did little or nothing. I view nootropics as akin to a biological lottery; one good discovery pays for all. I forge on in the hopes of further striking gold in my particular biology. Your mileage will vary. All you have to do, all you can do is to just try it. Most of my experiences were in my 20s as a right-handed 5’11 white male weighing 190-220lbs, fitness varying over time from not-so-fit to fairly fit. In rough order of personal effectiveness weighted by costs+side-effects, I rank them as follows:

Brain Pill™ combines the most powerful, clinically proven ingredients on the forefront of brain productivity and memory research. Each of our carefully selected ingredients is potent and effective on its own, but together, our research goal was to create far and away the ultimate synergistic combination for enhancing mental clarity, alertness and overall brain function.
The use of cognition-enhancing drugs by healthy individuals in the absence of a medical indication spans numerous controversial issues, including the ethics and fairness of their use, concerns over adverse effects, and the diversion of prescription drugs for nonmedical uses, among others.[1][2] Nonetheless, the international sales of cognition-enhancing supplements exceeded US$1 billion in 2015 when global demand for these compounds grew.[3]