Editing Nootropic (section)

===Cholinergics===
{{Main|Cholinergic}}
Some supposed nootropic substances are compounds and analogues of [[choline]], a [[precursor (chemistry)|precursor]] of acetylcholine (a [[neurotransmitter]]) and [[phosphatidylcholine]] (a structural component of [[cell membrane]]s).
* [[Alpha-GPC]] – L-alpha glycerylphosphorylcholine has been studied only in the context of cognitive performance alongside other substances such as caffeine.<ref>{{cite journal| vauthors = Parker AG, Byars A, Purpura M, Jäger R |date=September 21, 2015|title=The effects of alpha-glycerylphosphorylcholine, caffeine or placebo on markers of mood, cognitive function, power, speed, and agility|journal=Journal of the International Society of Sports Nutrition|volume=12|issue=Suppl 1|pages=P41|doi=10.1186/1550-2783-12-S1-P41|issn=1550-2783|pmc=4595381 |doi-access=free }}</ref>
* [[Choline bitartrate]] – Choline bitartrate is a [[tartaric acid]] salt containing choline (41% choline by molecular weight). One meta-analysis found choline bitartrate to be ineffective at improving any measure of cognitive performance.<ref>{{cite journal | vauthors = Lippelt DP, van der Kint S, van Herk K, Naber M | title = No Acute Effects of Choline Bitartrate Food Supplements on Memory in Healthy, Young, Human Adults | journal = PLOS ONE | volume = 11 | issue = 6 | pages = e0157714 | date = June 24, 2016 | pmid = 27341028 | pmc = 4920398 | doi = 10.1371/journal.pone.0157714 | doi-access = free | bibcode = 2016PLoSO..1157714L }}</ref>
* [[Citicoline]] – Compound consisting of choline and [[cytidine]]. A meta-analysis found that it may be effective for improving memory and learning in older people with mild cognitive decline, and in people recovering from a stroke.<ref>{{cite journal | vauthors = Fioravanti M, Buckley AE | title = Citicoline (Cognizin) in the treatment of cognitive impairment | journal = Clinical Interventions in Aging | volume = 1 | issue = 3 | pages = 247–251 | date = September 2006 | pmid = 18046877 | pmc = 2695184 | doi = 10.2147/ciia.2006.1.3.247 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Franco-Maside A, Caamaño J, Gómez MJ, Cacabelos R | title = Brain mapping activity and mental performance after chronic treatment with CDP-choline in Alzheimer's disease | journal = Methods and Findings in Experimental and Clinical Pharmacology | volume = 16 | issue = 8 | pages = 597–607 | date = October 1994 | pmid = 7760585 }}</ref>