For example, a study published in the journal Psychopharmacology in 2000 found that ginkgo improved attention. A 2001 study in the journal Human Psychopharmacology suggested that it improves memory. Nevertheless, in a review of studies on ginkgo in healthy people, researchers found no good evidence that it improved mental abilities, according to a 2002 report in Psychopharmacology Bulletin.

Freshly brewed tea. Two to three cups a day of freshly brewed tea -- hot or iced -- contains a modest amount of caffeine which, when used "judiciously," says Kulze -- can boost brain power by enhancing memory, focus, and mood. Tea also has potent antioxidants, especially the class known as catechines, which promotes healthy blood flow. Bottled or powdered teas don't do the trick, however, says Kulze. "It has to be freshly brewed." Tea bags do count, however.
The nootropics community is surprisingly large and involved. When I wade into forums and the nootropics subreddit, I find members trading stack recipes and notifying each other of newly synthesized compounds. Some of these “psychonauts” seem like they’ve studied neuroscience; others appear to be novices dipping their toes into the world of cognitive enhancement. But all of them have the same goal: amplifying the brain’s existing capabilities without screwing anything up too badly. It’s the same impulse that grips bodybuilders—the feeling that with small chemical tweaks and some training, we can squeeze more utility out of the body parts we have. As Taylor Hatmaker of the Daily Dot recently wrote, “Together, these faceless armchair scientists seek a common truth—a clean, unharmful way to make their brains better—enforcing their own self-imposed safety parameters and painstakingly precise methods, all while publishing their knowledge for free, in plain text, to relatively crude, shared databases."
One fairly powerful nootropic substance that, appropriately, has fallen out of favor is nicotine. It’s the chemical that gives tobacco products their stimulating kick. It isn’t what makes them so deadly, but it does make smoking very addictive. When Europeans learned about tobacco’s use from indigenous tribes they encountered in the Americas in the 15th and 16th centuries, they got hooked on its mood-altering effects right away and even believed it could cure joint pain, epilepsy, and the plague. Recently, researchers have been testing the effects of nicotine that’s been removed from tobacco, and they believe that it might help treat neurological disorders including Parkinson’s disease and schizophrenia; it may also improve attention and focus. But, please, don’t start smoking or vaping. Check out these 14 weird brain exercises that make you smarter.
Pyritinol: Pyritinol has anti-oxidant effects for supporting the long-term health of the brain. But its primary benefit is aiding glucose uptake for periods of extended mental strain. If you are studying or working for a long period of time, your brain will start to diminish its glucose (sugar) stores which are the primary way that the brain derives its energy.
Since the discovery of the effect of nootropics on memory and focus, the number of products on the market has increased exponentially. The ingredients used in a supplement can tell you about the effectiveness of the product. Brain enhancement pills that produce the greatest benefit are formulated with natural vitamins and substances, rather than caffeine and synthetic ingredients. In addition to better results, natural supplements are less likely to produce side effects, compared with drugs formulated with chemical ingredients.
Those bright, round yolks are rich in choline, a B vitamin-like nutrient. When you eat eggs, your brain uses choline to make acetylcholine, a neurotransmitter that may be important for maintaining memory and communication among brain cells. Boston University researchers tracked the eating habits of nearly 1,400 healthy adults for 10 years and found that choline intake correlated positively with better performance on certain types of memory tests. These simple brain exercises will help you get smarter.
Starting from the studies in my meta-analysis, we can try to estimate an upper bound on how big any effect would be, if it actually existed. One of the most promising null results, Southon et al 1994, turns out to be not very informative: if we punch in the number of kids, we find that they needed a large effect size (d=0.81) before they could see anything:
Systematic reviews and meta-analyses of clinical human research using low doses of certain central nervous system stimulants found enhanced cognition in healthy people.[21][22][23] In particular, the classes of stimulants that demonstrate cognition-enhancing effects in humans act as direct agonists or indirect agonists of dopamine receptor D1, adrenoceptor A2, or both types of receptor in the prefrontal cortex.[21][22][24][25] Relatively high doses of stimulants cause cognitive deficits.[24][25]