Recent findings also suggest that taking extra vitamins could help preserve memory, especially as we age. Researchers at Australia's University of Sydney tested 117 people in a retirement home by putting them through a battery of mental tests that included remembering a string of words, listing as many words as possible that begin with a certain letter of the alphabet, and doing mental addition and subtraction. Those who regularly took vitamin C, they found, scored higher on the tests.
Of course, before wrapping up this section on psychedelics, I’ll address the topics of where to actually buy the stuff. There are a variety of websites that sell psychedelics, but not all ingredient, chemical or quality sourcing is created equal, nor is there any guarantee that any substance you are purchasing is not laced with undesirable compounds. Heck, I get my psilocybin from a farmer in Wisconsin who is a personal friend, and other ingredients from close acquaintances who have their own sources. I know it may seem unfair, but sometimes sourcing comes down to “who ya know” and doing your own due diligence on that person’s source.
Microdosing with Ketamine: Ketamine is a general anesthetic that is most commonly used on animals but ironically was originally devised for and tested on humans. Users of ketamine have claimed increased compassion and sensitivity to others, an increase in joy of life, and a reduced fear around death. Finding your ideal microdose of ketamine can be tricky, so it is important to start just a bit below the recommended doses. Taking ketamine sublingually (under the tongue) is the most effective and direct route of administration, and a sublingual microdose is about .75 milligrams per kilogram of body weight, although you can get a significant mood enhancement with as little as 0.2 milligrams per kilogram of body weight. I’d recommend that you never mix ketamine with any drugs that depress breathing such as alcohol, opioids, and tramadol, as it is an extremely calming agent that can produce a heavy sedative effect if you’re not careful or if you combine it with other sedative-like compounds. I’ve found a microdose of ketamine to be best combined with a trip to a float tank, or any other environment that involves sensory deprivation and introspection.
Dr Hart explained how communication between the gut and the brain is controlled via our immune system, our endocrine system (hormones) and our central nervous system, which are all under the influence of the bacteria in our gut. The types and amount of these bacteria, known as our gut microbiome, can be directly impacted by factors such as diet, stress, pollution and medications (2) and the composition of the microbiome is also understood to affect one’s susceptibility to food sensitivities and intolerances (3).  
The nootropics I’m taking are called RISE, and they're made by a company called Nootrobox, which was started by Geoffrey Woo, a young Stanford computer science graduate. There's no one common ingredient in nootropics; what unites them is the intent to improve brain performance. The RISE stack, which costs $29 plus shipping for 30 pills, contains 350 mg of bacopa monnieri powder (an herb that is commonly used medicinally in South Asia), 100 mg of L-theanine (an amino acid found in green tea), and 50 mg of caffeine (about the amount in a can of Diet Coke). Like most nootropics, the RISE stack itself isn't FDA-approved for use as a cognitive enhancer, but Nootrobox says that the compounds within it are approved as dietary supplements. "We use the precise ingredients at the right dosages and the right ratios as supported by double-blind, peer-reviewed clinicals," Nootrobox's site claims.
A third of participants in clinical trials on Modafinil have reported crippling headaches.  An additional 11% experienced nausea, while others reported an array of other side-effects ranging from nervousness to diarrhea.  Dizziness and insomnia may also result from Modafinil use.   I can attest that the side effects are very real.  In fact, I had to stop using Modafinil after 2 days when my headaches became so intense I ended up at the ER.
Qualia Mind, meanwhile, combines more than two dozen ingredients that may support brain and nervous system function – and even empathy, the company claims – including vitamins B, C and D, artichoke stem and leaf extract, taurine and a concentrated caffeine powder. A 2014 review of research on vitamin C, for one, suggests it may help protect against cognitive decline, while most of the research on artichoke extract seems to point to its benefits to other organs like the liver and heart. A small company-lead pilot study on the product found users experienced improvements in reasoning, memory, verbal ability and concentration five days after beginning Qualia Mind.

“In an era of confusion about what we should eat, Brain Food is a shining light. This is the straight story about ‘neuro-nutrition’ firmly rooted in research by a neuroscientist who has a deep understanding of how food affects our cognitive health. Dr. Mosconi gives us advice we can easily implement into our lives and a story about the science behind it that is both delightful and accessible. A must read!”
We did note a significant warning with this product, namely that the caffeine it contains may cause a negative impact, mainly that some users may experience the jitters. Their dosage suggests that one can take up to 6 pills a day, which we felt was too many. These issues made us a little wary of the product, even though they seem to know the right ingredients to include.
The single most reliable way to protect our brain cells as we age, most researchers agree, is to eat plenty of fruits and vegetables, which are chock-full of antioxidants and nutrients. In a study published in the October 1997 issue of the American Journal of Clinical Nutrition, researchers tested 260 people aged 65 to 90 with a series of mental exercises that involved memorizing words or doing mental arithmetic. The top performers were those who consumed the most fruits and vegetables and ate the least artery-clogging saturated fat.
Bought 5,000 IU soft-gels of Vitamin D-334 (; FDA adverse events) because I was feeling very apathetic in January 2011 and not getting much done, even slacking on regular habits like Mnemosyne spaced repetition review or dual n-back or my Wikipedia watchlist. Introspecting, I was reminded of depression & dysthymia & seasonal affective disorder.
It's been widely reported that Silicon Valley entrepreneurs and college students turn to Adderall (without a prescription) to work late through the night. In fact, a 2012 study published in the Journal of American College Health, showed that roughly two-thirds of undergraduate students were offered prescription stimulants for non-medical purposes by senior year.
Racetams, such as piracetam, oxiracetam, and aniracetam, which are often marketed as cognitive enhancers and sold over-the-counter. Racetams are often referred to as nootropics, but this property is not well established.[31] The racetams have poorly understood mechanisms, although piracetam and aniracetam are known to act as positive allosteric modulators of AMPA receptors and appear to modulate cholinergic systems.[32]