Butyrylcholinesterase (BCHE) is a major acetylcholine hydrolyzing enzyme in the circulation. Although it is present in significant amounts (~3 mg/L) in human plasma, no endogenous physiological substrate has been described for this enzyme. It can degrade a large number of ester-containing compounds in addition to acylcholines. Thus, it is likely to play significant pharmacological and toxicological roles. It is thought to be involved in the pathological process of Alzheimer's disease (AD) by depleting acetylcholine. In contrast to ACHE, it attenuates amyloid fibril formation in vitro. BCHE inhibitors have been used to delay symptoms of AD patients by virtue of their ability to enhance acetylcholine availability. Its involvement in a cholinergic anti-inflammatory pathway connect BCHE and ACHE with a possible marker of low-grade systemic inflammation observed in Type-2 diabetes, obesity, hypertension, coronary heart disease, and AD. BCHE can exist in monomeric and multimeric forms. The expressed recombinant mouse BCHE contains multiple forms that consist of soluble monomers, dimers, and tetramers.