ETH-LAD, 6-ethyl-6-nor-lysergic acid diethylamide is an analogue of LSD. It's human psychopharmacology was first described by Alexander Shulgin in the book TiHKAL. ETH-LAD is a psychedelic drug similar to LSD, and is slightly more potent than LSD itself, with an active dose reported at between 20 and 150 micrograms. ETH-LAD has subtly different effects to LSD, described as less demanding.
Andrew J. Hoffman, David E. Nichols: Synthesis and LSD-like discriminative stimulus properties in a series of N(6)-alkyl norlysergic acid N,N-diethylamide derivatives. In: Journal of Medicinal Chemistry. 28, 1985, p. 1252–1255, doi:10.1021/jm00147a022.
V. J. Watts, R. B. Mailman, C. P. Lawler, K. A. Neve, D. E. Nichols: LSD and structural analogs: pharmacological evaluation at D1 dopamine receptors. In: Psychopharmacology. 118, 1995, p. 401–409, doi:10.1007/BF02245940.
T. Niwaguchi, Y. Nakahara, H. Ishii: Studies on lysergic acid diethylamide and related compounds. IV. Syntheses of various amide derivatives of norlysergic acid and related compounds. In: Yakugaku Zasshi. Vol. 96, No. 5, May 1976, p. 673–678, PMID 987200.
Robert C. Pfaff, Xuemei Huang, Danuta Marona-Lewicka, Robert Oberlender and David E. Nichols: Lysergamides Revisited. In: NIDA Research Monograph 146: Hallucinogens: An Update. p. 52, 1994, United States Department of Health and Human Services.
^Hoffman AJ, Nichols DE (September 1985). "Synthesis and LSD-like discriminative stimulus properties in a series of N(6)-alkyl norlysergic acid N,N-diethylamide derivatives". Journal of Medicinal Chemistry. 28 (9): 1252–5. doi:10.1021/jm00147a022. PMID4032428.