Main: N1-Methyl-Lysergic Acid Diethylamide (MLD-41) is a derivative of LSD. The 1-methyl homologue of LSD has more of somatic than sensory effect, has fewer visuals and is less well accepted than LSD, with the range of dosages being from 100 to 300 micrograms. This indicates that it is perhaps a third the potency of LSD which is in accord with both pupillary dilation and reflex action. However, the cardiovascular responses are actually increased. Besides being less potent than LSD, it appears to have a slower onset but it is equally long lived. There is cross-tolerance between MLD-41 and LSD. Hepatic N-demethylation of MLD-41 (1-methyl-LSD)--producing the parent compound in vivo as a metabolite—may account for both the reduced potency and protracted onset of MLD-41 as a psychedelic. That is, the psychedelic activity of MLD-41 may be partially (or even entirely) due to the formation of LSD as an active metabolite. Metabolism of other 1-methylated-ergoloids to their secondary amine derivatives has been frequently noted in mammals.