LPD-824

Use and effects

The drug has been reported to have mild and relatively short-lasting LSD-like effects in humans at an oral dose of 800μg equivalent to one-tenth this amount of LSD (i.e., 80μg). Based on different clinical studies, it is estimated to be 5 to 10% as potent as LSD in humans. Its duration was shorter than that of LSD, lasting around 5hours as opposed to 7hours in the case of LSD. The drug produced nausea at small doses in humans, which was dose-limiting in terms of evaluating its effects.

Interactions

Pharmacology

Pharmacodynamics

LPD-824 is known to be a serotonin receptor modulator, including of the serotonin 5-HT2A receptor, where it acted as a partial agonist with about 17-fold lower potency than LSD but an efficacy slightly higher than that of LSD in terms of phosphatidylinositol (PI) hydrolysis. It also showed affinities for the serotonin 5-HT2C and 5-HT1A receptors similar to those of LSD.

It had about 5 to 10% of the potency of LSD in preclinical studies with animals, for instance in terms of serotonin antagonism in the rat uterus and hyperthermia in rabbits. It is described as a very strong hypotensive agent in animals. In subsequent rodent drug discrimination tests, LPD-824 fully substituted for LSD, albeit with only about 16 to 25% of the potency.

History

LPD-824 was first described in the scientific literature by Albert Hofmann and colleagues by 1955.

Society and culture

Legal status

Canada

LPD-824 is not a controlled substance in Canada as of 2025.

United States

LPD-824 is not an explicitly controlled substance in the United States. However, it could be considered a controlled substance under the Federal Analogue Act if intended for human consumption.

References

References

1. "Erowid Online Books : "TIHKAL" - #26 LSD-25".
2. (30 October 2007). "Toward a molecular understanding of hallucinogen action".
3. (2012). "Structure–activity relationships of serotonin 5-HT2A agonists". Wiley Interdisciplinary Reviews: Membrane Transport and Signaling.
4. (February 1974). "The role of hydrophobicity in the antiserotonin activity of LSD analogs". Research Communications in Chemical Pathology and Pharmacology.
5. (1978). "Ergot Alkaloids and Related Compounds". Springer Berlin Heidelberg.
6. (1959). "Relationships of psychotomimetic to anti-serotonin potencies of congeners of lysergic acid diethylamide (LSD-25)". Psychopharmacologia.
7. (2018). "Current Topics in Behavioral Neurosciences".
8. (1965). "D-Lysergic acid diethylamide (LSD): A review of its present status". Clinical Pharmacology and Therapeutics.
9. (1956). "Spezifische Hemmung von 5-Oxytryptamin-Effekten durch Lysergsäurediäthylamid und ähnliche Körper". Naunyn-Schmiedebergs Archiv für Experimentelle Pathologie und Pharmakologie.
10. (1956). "Neuropharmacology: Transactions of the 2nd Conference, May 25-27, 1955, Princeton, N.J.". Josiah Macy.
11. (January 1992). "Stereoselective LSD-like activity in d-lysergic acid amides of (R)- and (S)-2-aminobutane". Journal of Medicinal Chemistry.
12. (May 1989). "Stereoselective aspects of hallucinogenic drug action and drug discrimination studies of entactogens". Purdue University.
13. (1955). "Amide der stereoisomeren Lysergsäuren und Dihydro-lysergsäuren. 38. Mitteilung über Mutterkornalkaloide". Helvetica Chimica Acta.
14. (1957). "Psychotropic Drugs: Proceedings of the International Symposium on Psychotropic Drugs, Milan, May 9-11, 1957". Elsevier Publishing Company.
15. (September 1958). "The effect of (+)-lysergic acid diethylamide and other drugs on the carotid sinus reflex". British Journal of Pharmacology and Chemotherapy.
16. (July 1960). "Lysergic acid diethylamide (LSD-25). XXXI. Comparison by questionnaire of psychotomimetic activity of congeners on normal subjects and drug addicts". The Journal of Mental Science.
17. "Controlled Drugs and Substances Act".
18. (January 2026). "Orange Book: List of Controlled Substances and Regulated Chemicals (January 2026)". U.S. [[Department of Justice]]: [[Drug Enforcement Administration]] (DEA): Diversion Control Division.