Executive SummaryNomination Dimethylethanolamine (DMAE) was nominated by the NIEHS for toxicological characterization, including metabolism, reproductive and developmental toxicity, subchronic toxicity, carcinogenicity and mechanistic studies. The nomination is based on the potential for widespread human exposure to DMAE through its use in industrial and consumer products and an inadequate toxicological database. Studies to address potential hazards of consumer (e.g. dietary supplement) exposures, including use by pregnant women and children, and the potential for reproductive effects and carcinogenic effects are limited. DMAE and related ethanolamines appear to interfere with choline uptake and utilization and may also generate nitrosamines. Further studies are recommended to address these data gaps with special attention to pharmacokinetics and the influence of dietary choline. Consideration should be given to whether the bitartrate salt of DMAE (a form commonly used in dietary supplements) or other DMAE derivative is more appropriate than the free base for use in toxicology studies. Nontoxicological DataChemical Identification The principal compounds related to DMAE [108-01-0] that have common commercial uses and are discussed in this report, are DMAE aceglumate [3342-61-8], DMAE p-acetamidobenzoate (an ester) [2811-31-6], DMAE p-acetamidobenzoate (a salt); Deaner  [3635-74-3], DMAE bitartrate [5988 51-2], DMAE dihydrogen phosphate [6909-62-2], DMAE hydrochloride [2498-25-1], DMAE orotate [1446-06-6], DMAE succinate; tonibral [10549-59-4], centrophenoxine; dimethylethanolamine p-chlorophenoxyacetate hydrochloride [3685-84-5], centrophenoxine orotate [27166-15-0], and meclofenoxate; DMAE p-chlorophenoxyacetate [51-68-3].