Catalyzes the hydrolysis of endogenous amidated lipids like anandamide (AEA or N-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-ethanolamine) and eicosapentaneoyl ethanolamide (EPEA or (5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl) ethanolamine), as well as other fatty amides, to their corresponding fatty acids, thereby regulating the signaling functions of these molecules (PubMed:21562563, PubMed:30911178). EPEA promotes dauer formation and may constitute a signal of high nutrient availability (PubMed:21562563). Breakdown of EPEA may promote lifespan extension when nutrient availability is high (PubMed:21562563). Facilitates axon regeneration after injury by degradating inhibitory compounds such as AEA (PubMed:23072806). FAAH cooperates with PM20D1 in the hydrolysis of amino acid-conjugated fatty acids such as N-fatty acyl glycine and N-fatty acyl-L-serine, thereby acting as a physiological regulator of specific subsets of intracellular, but not of extracellular, N-fatty acyl amino acids (By similarity). H2O + N-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-ethanolamine = (5Z,8Z,11Z,14Z)-eicosatetraenoate + ethanolamine (9Z)-octadecenamide + H2O = (9Z)-octadecenoate + NH4(+) (5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl) ethanolamine + H2O = (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate + ethanolamine H2O + N-(9Z-hexadecenoyl) ethanolamine = (9Z)-hexadecenoate + ethanolamine H2O + N-(9Z-octadecenoyl) ethanolamine = (9Z)-octadecenoate + ethanolamine H2O + N-octadecanoyl ethanolamine = ethanolamine + octadecanoate H2O + N-docosanoyl-ethanolamine = docosanoate + ethanolamine H2O + N-(15Z-tetracosenoyl)-ethanolamine = (15Z)-tetracosenoate + ethanolamine H2O + N-hexadecanoylethanolamine = ethanolamine + hexadecanoate H2O + N-(9Z,12Z-octadecadienoyl)-ethanolamine = (9Z,12Z)-octadecadienoate + ethanolamine (9Z)-octadecenoate + glycine = H2O + N-(9Z-octadecenoyl)glycine H2O + N-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-glycine = (5Z,8Z,11Z,14Z)-eicosatetraenoate + glycine H2O + N-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-L-serine = (5Z,8Z,11Z,14Z)-eicosatetraenoate + L-serine Expressed in the pharynx, some pharyngeal neurons, the posterior intestine and anal depressor muscles. Viable. Reduction (50 percent) in the frequency of motoneuron axon regeneration in young adults but not in L4 larvae. Belongs to the amidase family.