Nootropics are substances that enhance cognition and support healthy brain function. Sometimes people refer to them as "smart drugs" or the "limitless pill." They include various foods, nutraceuticals (supplements), and pharmaceuticals (drugs). Unfortunately none comes close to enabling any fiction-inspired capacities of superintelligence (yet), but some may make a practical difference for many people. I’ve used several nootropics for years. And I’m exploring ways to incorporate others into my diet, if they’re applicable to my personal situation and meet a few general criteria: First, I look for nootropics supported by multiple studies on humans – not just anecdotal evidence, one study, or studies on non-human animals. Although I've nothing against the health benefits of placebo, I prefer knowing that something more than only placebo is at work. Second, I look for nootropics with the highest ratios of efficacy to expense. Given innumerable options and a limited budget, I want to do more than just empty my wallet. Third, I look for nootropics that are legal and generally safe. If it'll put me in a hospital or a prison, it’s not worth it. Based on those criteria, I’ve compiled a list of top tier natural nootropics that actually work. These are, to the best of my knowledge, the most well-researched and effective nootropics available in the United States without a prescription. This information is for educational purposes only. It is not medical advice. Please consult a physician before and during use of these and other nootropics. 1) Ashwagandha Ashwagandha, also known as Withania Somnifera, is a plant in the nightshade family and cultivated in Asia. Supplements may enhance relaxation, according to multiple peer-reviewed, double-blind, placebo-controlled studies: Langade D, Kanchi S, Salve J, Debnath K, Ambegaokar D. Cureus. 2019 Sep 28;11(9):e5797. doi: 10.7759/cureus.5797. PMID: 31728244; PMCID: PMC6827862. Lopresti AL, Smith SJ, Malvi H, Kodgule R. Medicine (Baltimore). 2019 Sep;98(37):e17186. doi: 10.1097/MD.0000000000017186. PMID: 31517876; PMCID: PMC6750292. Salve J, Pate S, Debnath K, Langade D. Cureus. 2019 Dec 25;11(12):e6466. doi: 10.7759/cureus.6466. PMID: 32021735; PMCID: PMC6979308. Chengappa KNR, Brar JS, Gannon JM, Schlicht PJ. J Clin Psychiatry. 2018 Jul 10;79(5):17m11826. doi: 10.4088/JCP.17m11826. PMID: 29995356. Choudhary D, Bhattacharyya S, Joshi K. J Evid Based Complementary Altern Med. 2017 Jan;22(1):96-106. doi: 10.1177/2156587216641830. Epub 2016 Apr 6. PMID: 27055824; PMCID: PMC5871210. Chandrasekhar K, Kapoor J, Anishetty S. Indian J Psychol Med. 2012 Jul;34(3):255-62. doi: 10.4103/0253-7176.106022. PMID: 23439798; PMCID: PMC3573577. Cooley K, Szczurko O, Perri D, Mills EJ, Bernhardt B, Zhou Q, Seely D. PLoS One. 2009 Aug 31;4(8):e6628. doi: 10.1371/journal.pone.0006628. PMID: 19718255; PMCID: PMC2729375. Mahdi AA, Shukla KK, Ahmad MK, Rajender S, Shankhwar SN, Singh V, Dalela D. Evid Based Complement Alternat Med. 2009 Sep 29;2011:576962. doi: 10.1093/ecam/nep138. Epub ahead of print. PMID: 19789214; PMCID: PMC3136684. Andrade C, Aswath A, Chaturvedi SK, Srinivasa M, Raguram R. Indian J Psychiatry. 2000 Jul;42(3):295-301. PMID: 21407960; PMCID: PMC2958355. Ashwagandha supplements may also enhance energy, motivation, social functioning, and subjective well-being. Evidence for these effects may not be as reliable. See the Ashwagandha article at Examine.com for more studies and details. The KSM-66® extract of Ashwagandha is an ingredient in Thrivous Serenity Nightly Nootropic. 2) Bacopa Monnieri Bacopa Monnieri is a perennial creeping herb native to wetlands worldwide. Supplements may enhance memory, according to multiple peer-reviewed, double-blind, placebo-controlled studies: Benson S, Downey LA, Stough C, Wetherell M, Zangara A, Scholey A. Phytother Res. 2014 Apr;28(4):551-9. doi: 10.1002/ptr.5029. Epub 2013 Jun 21. PMID: 23788517. Downey LA, Kean J, Nemeh F, Lau A, Poll A, Gregory R, Murray M, Rour ...