In fact CIA documents show that a U.S. source for LSD supply was desired. In 1953 the CIA provided Eli Lilly with funding to attempt synthesis of LSD for CIA use without the need for the expensive and scarce reagents required by Sandoz. A year later, Lilly chemists succeeded in their quest, and subsequent supplies were from Lilly[1,2]. Another more potent chemical used by MK-Ultra, BZ (3-quinuclidinyl benzilate), was produced by Hoffman-La Roche.

References:
CIA documents: Document #24, 16 November, 1953, Subject: ARTICHOKE Conference; Document #268, 23 October, 1953, Subject: Meeting in Director's Office at 1100 hours on 23 October with Mr. Wisner and [deleted]; Document # 316,6 January,1954, Subject: Lysergic Acid Diethylamide (LSD-25); and Document #338, 26 October 1954, Subject: Potential Large Scale Availability of LSD through newly discovered synthesis by [deleted]; interviews with Sandoz and Lilly former executives; and Sidney Gottlieb's testimony before Kennedy subcommittee, 1977, p. 203.
Marks, John (1979). The Search for the Manchurian Candidate: CIA and Mind Control. W W Norton & Co Ltd, 264. ISBN 0393307948
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