Either prescription or illegal, daily use of testosterone would not be cheap. On the other hand, if I am one of the people for whom testosterone works very well, it would be even more valuable than modafinil, in which case it is well worth even arduous experimenting. Since I am on the fence on whether it would help, this suggests the value of information is high.

“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!”
Regardless, while in the absence of piracetam, I did notice some stimulant effects (somewhat negative - more aggressive than usual while driving) and similar effects to piracetam, I did not notice any mental performance beyond piracetam when using them both. The most I can say is that on some nights, I seemed to be less easily tired when writing or editing or n-backing (and I felt less tired than ICON 2011 than ICON 2010), but those were also often nights I was also trying out all the other things I had gotten in that order from Smart Powders, and I am still dis-entangling what was responsible. (Probably the l-theanine or sulbutiamine.)

(I was more than a little nonplussed when the mushroom seller included a little pamphlet educating one about how papaya leaves can cure cancer, and how I’m shortening my life by decades by not eating many raw fruits & vegetables. There were some studies cited, but usually for points disconnected from any actual curing or longevity-inducing results.)
These superfoods contain powerful antioxidants that can protect your brain from toxic free radicals. One study of older women found that those who ate the most green, leafy vegetables had minds that functioned like those of women who were one to two years younger than they were, compared to women who ate fewer leafy greens, according to the Alzheimer’s Association. Here are some habits that will keep your brain healthy throughout your entire life.

Conversely, you have to consider that the long term effects of Modafinil haven’t been studies very well. It significantly upsets sleep cycles, and 50% of Modafinil users report a number of short term side effects, such as mild to severe headaches, insomnia, nausea, anxiety, nervousness, hypertension, decreased appetite, and weight loss. PET scans show it affects the same areas of the brain that are stimulated by substance abuse.
Nootropics aren’t new—the word was coined in 1972 by a Romanian doctor, Corneliu E. Giurgea—but the Silicon Valley-led body-hacking movement, epitomized by food replacements like Soylent and specialized supplements like Bulletproof Coffee, seems to have given them new life. There are dozens of online forums, including an active subreddit, where nootropics users gather to exchange stack recipes and discuss the effects of various combinations of compounds. And although their "brain-enhancing" effects are still generally unproven, nootropics proponents point to clinical studies showing that certain compounds can increase short-term memory, reduce reaction time, and improve spatial awareness.

One of the most common strategies to beat this is cycling. Users who cycle their nootropics take them for a predetermined period, (usually around five days) before taking a two-day break from using them. Once the two days are up, they resume the cycle. By taking a break, nootropic users reduce the tolerance for nootropics and lessen the risk of regression and tolerance symptoms.
A fancier method of imputation would be multiple imputation using, for example, the R library mice (Multivariate Imputation by Chained Equations) (guide), which will try to impute all missing values in a way which mimicks the internal structure of the data and provide several possible datasets to give us an idea of what the underlying data might have looked like, so we can see how our estimates improve with no missingness & how much of the estimate is now due to the imputation:
Which brain boosting supplement took home the Editor's Choice Award? We understand how important it is for many individuals to stay alert, focused and on full power all day. Whether you are a busy mom, top IT guru or student, life sometimes needs a boost - smart drugs are the answer, so to help you reach your full potential and shine, we listed our top 5 brain boosting products. To come up with our top products, we evaluated scores of cognitive energy enhancers, from over-the-counter to all natural products. We listed them here in order of superiority and based our research on the following criteria:
One claim was partially verified in passing by Eliezer Yudkowsky (Supplementing potassium (citrate) hasn’t helped me much, but works dramatically for Anna, Kevin, and Vassar…About the same as drinking a cup of coffee - i.e., it works as a perker-upper, somehow. I’m not sure, since it doesn’t do anything for me except possibly mitigate foot cramps.)
To our Brainfood students and youth supporters: It’s your potential that inspired us, your laughter that sustained us, your incredible talent that challenged us to dig deep and build programs that you deserve. Whether you were with us for one year or one week, know that there’s probably a Brainfood staffer who has bragged about how awesome you are. We hope that what you learned in Brainfood sticks with you, even if it’s just using that pumpkin chocolate chip muffin recipe to make someone’s day a little brighter. You’ve given us hope and made us so very proud. Thank you. Now go out there, get what’s yours, and bless the world with your many, many talents.
Noopept is a Russian stimulant sometimes suggested for nootropics use as it may be more effective than piracetam or other -racetams, and its smaller doses make it more convenient & possibly safer. Following up on a pilot study, I ran a well-powered blind randomized self-experiment between September 2013 and August 2014 using doses of 12-60mg Noopept & pairs of 3-day blocks to investigate the impact of Noopept on self-ratings of daily functioning in addition to my existing supplementation regimen involving small-to-moderate doses of piracetam. A linear regression, which included other concurrent experiments as covariates & used multiple imputation for missing data, indicates a small benefit to the lower dose levels and harm from the highest 60mg dose level, but no dose nor Noopept as a whole was statistically-significant. It seems Noopept’s effects are too subtle to easily notice if they exist, but if one uses it, one should probably avoid 60mg+.
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]