1H-LSD

1H-LSD
Clinical data
Other names	1-Hexanoyl-LSD; SYN-L-027
Legal status
Legal status	DE: NpSG (Industrial and scientific use only); UK: Under Psychoactive Substances Act; US: Unscheduled (may be covered by the Federal Analogue Act if sold for human consumption); UN: Unscheduled;
Identifiers
	IUPAC name (6aR,9R)-N,N-diethyl-6-methyl-4-hexanoyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg]quinoline-9-carboxamide;
CAS Number	3028949-65-4;
PubChem CID	170763690;
Chemical and physical data
Formula	C26H35N3O2
Molar mass	421.585 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CN1CC(C=C2[C@H]1Cc1cn(C(=O)CCCCC)c3cccc2c31)C(=O)N(CC)CC;
	InChI InChI=1S/C26H35N3O2/c1-5-8-9-13-24(30)29-17-18-15-23-21(20-11-10-12-22(29)25(18)20)14-19(16-27(23)4)26(31)28(6-2)7-3/h10-12,14,17,19,23H,5-9,13,15-16H2,1-4H3/t19?,23-/m1/s1; Key:RSBBZALMPUUEKF-LEQGEALCSA-N;

1H-LSD, also known as 1-hexanoyl-LSD or as SYN-L-027,^[1] is an acylated derivative of lysergic acid diethylamide (LSD), with a six carbon hexanoyl chain attached to the N1 position.^[2] It acts as a prodrug for LSD, and in animal studies produces drug-appropriate responding with a similar potency to short-chain homologues such as ALD-52 and 1P-LSD, in contrast to the 4 and 5 carbon homologues 1B-LSD and 1V-LSD which are several times weaker.^[3]

Use and effects

1H-LSD produces similar effects to LSD with a shorter metabolic half-life.^{[citation needed]} There are no documented cases of it being used recreationally.^[4]

Interactions

Chemistry

Analogues

Analogues of 1H-LSD include ALD-52 (1A-LSD), 1P-LSD, 1cP-LSD, 1DD-LSD, 1cP-AL-LAD, and 1P-ETH-LAD, among others.

Society and culture

Legal status

Canada

1H-LSD is not an explicitly nor implicitly controlled substance in Canada as of 2025.^[5]

United States

1H-LSD is not an explicitly controlled substance in the United States.^[6] However, it could be considered a controlled substance under the Federal Analogue Act if intended for human consumption.

References

↑ WO 2024/028495, Stratford A, Williamson JP, "Prodrugs of Substituted Ergolines", published 8 February 2024, assigned to Synex Holdings BV
↑ "1H-LSD". АИПСИН (in Russian). Retrieved 1 January 2026.
↑ Brandt SD, Kavanagh PV, Gare S, Stratford A, Halberstadt AL (July 2024). "Analytical and behavioral characterization of 1-hexanoyl-LSD (1H-LSD)" (PDF). Drug Testing and Analysis. 17 (4): 561–569. doi:10.1002/dta.3767. PMC 11994379. PMID 38965834.
↑ Brandt SD, Kavanagh PV, Gare S, Stratford A, Halberstadt AL (April 2025). "Analytical and behavioral characterization of 1-hexanoyl-LSD (1H-LSD)". Drug Testing and Analysis. 17 (4): 561–569. doi:10.1002/dta.3767. PMC 11994379. PMID 38965834.
↑ "Controlled Drugs and Substances Act". Department of Justice Canada. 5 December 2025. Retrieved 20 January 2026.
↑ Orange Book: List of Controlled Substances and Regulated Chemicals (January 2026) (PDF), United States: U.S. Department of Justice: Drug Enforcement Administration (DEA): Diversion Control Division, January 2026

External links

1H-LSD - Isomer Design

[WO2024028495-1] WO 2024/028495, Stratford A, Williamson JP, "Prodrugs of Substituted Ergolines", published 8 February 2024, assigned to Synex Holdings BV

[Aipsin-2] "1H-LSD". АИПСИН (in Russian). Retrieved 1 January 2026.

[pmid38965834-3] Brandt SD, Kavanagh PV, Gare S, Stratford A, Halberstadt AL (July 2024). "Analytical and behavioral characterization of 1-hexanoyl-LSD (1H-LSD)" (PDF). Drug Testing and Analysis. 17 (4): 561–569. doi:10.1002/dta.3767. PMC 11994379. PMID 38965834.

[1H-LSD_Data-4] Brandt SD, Kavanagh PV, Gare S, Stratford A, Halberstadt AL (April 2025). "Analytical and behavioral characterization of 1-hexanoyl-LSD (1H-LSD)". Drug Testing and Analysis. 17 (4): 561–569. doi:10.1002/dta.3767. PMC 11994379. PMID 38965834.

[CDSA2025-5] "Controlled Drugs and Substances Act". Department of Justice Canada. 5 December 2025. Retrieved 20 January 2026.

[OrangeBook2026-6] Orange Book: List of Controlled Substances and Regulated Chemicals (January 2026) (PDF), United States: U.S. Department of Justice: Drug Enforcement Administration (DEA): Diversion Control Division, January 2026

[1]