ALD-52 was long thought to be a readily convertedprodrug ofLSD.[22][8][1] However, this was not empirically confirmed until formal studies were finally done in the 2010s and 2020s.[8][4][5][23]
ALD-52 was clinically studied and found to producepsychedelic effects similar to those of LSD itself and to closely match the time–course of LSD in terms ofonset andduration.[4][6][7] However, in one study, it was claimed that ALD-52 seemed to modifycognition andbody image to a greater extent than LSD.[6][4][24] Both LSD and ALD-52 were reported to be active at doses of 0.5 to 1μg/kgorally (35–70μg for a 70-kg person).[4] Other sources found that ALD-52 was 91% aspotent as LSD (with LSD notably having 88% of themolecular weight of ALD-52) or that the two drugs wereequipotent.[6][22][4][12]
In his bookTiHKAL (Tryptamines I Have Known and Loved),Alexander Shulgin briefly discusses ALD-52, giving a dose range of 50 to 175μg orally and no onset or duration mentioned.[1] In other publications however, he gave a dose range of 100 to 200μg orally.[25][26] A few different individual accounts of the effects of ALD-52 were described by Shulgin.[1] One account found that there was lessvisual distortion than with LSD, that there was seemingly lessanxiety than with LSD, and that it was somewhat less potent than LSD.[1] Another claimed that it was more effective than LSD in increasingblood pressure.[1] One account could not tell ALD-52 and LSD apart.[1] Per Shulgin, if ALD-52 is a readily converted prodrug of LSD, then they should be equivalent in all regards (aside from a slight difference potency).[1]
An early study reported that ALD-52 surprisingly did not produce thehead-twitch response, a behavioral proxy ofpsychedelic effects, in mice.[4][29][30] It was subsequently suggested that this could be due to species differences in themetabolism of ALD-52.[31] However, later research found that ALD-52 does indeed produce the head-twitch response in mice and that the earlier findings were erroneous.[4] ALD-52 had about 45% of the molar potency of LSD in inducing the head-twitch response, whereas1P-LSD had about 38%,1V-LSD 36%, and1cP-LSD 31% of the molar potency of LSD in thisassay.[9][4]
ALD-52 was firstsynthesized and described in thescientific literature byAlbert Hofmann and Franz Troxler atSandoz in 1957.[4][13][14] The properties and effects of ALD-52 were studied and reported in the late 1950s and early 1960s.[4][13] It is said to be unclear whether ALD-52 ever circulated as arecreational drug similarly to LSD in the 1960s or subsequent decades.[18]
The LSD manufacturersTim Scully andNick Sand once claimed that the "Orange Sunshine" LSD they distributed during the 1967Summer of Love in theUnited States was actually ALD-52 rather than LSD.[15][1][18][32][16][17] More specifically, they had been apprehended bylaw enforcement in 1973 and the pair argued in court that same year that they had distributed ALD-52 rather than LSD.[15][1][16][17] This was notable as ALD-52 was not acontrolled substance and hence was not technically illegal in contrast to LSD.[15][1][16][17] However, the prosecution argued that ALD-52 readily converts into LSD and that thesynthesis of ALD-52 requires going through LSD as anintermediate.[1] In addition, they tested a sample of supposed ALD-52 that Sand and Scully provided to them via a friend which inadvertently turned out to be LSD.[15][16][17] The pair were found guilty, including of lying in court, and Scully was sentenced to 20years in prison while Sand received 15years in prison.[15][1][33][16] Later, in the 2000s and 2010s, Sand and Scully publicly admitted that they had never in fact manufactured or distributed ALD-52 and that "Orange Sunshine" was LSD all along.[15][33][16][17] They disclosed that they had unsuccessfully lied to the court in an attempt to exploit alegal loophole and avoid conviction and prison time, which they regretted.[15][33][16][17] The subject of the "Orange Sunshine" LSD was covered in the 2015 documentaryThe Sunshine Makers by Cosmo Feilding Mellen.[33][34]
ALD-52 was one of the earliest 1-acyllysergamides to be described.[9][8][4] It is a keyparent compound of the 1-acyllysergamide LSDprodrugs and served as inspiration for development of subsequent compounds of this series such as1P-LSD,1V-LSD, and1cP-LSD, among many others.[9][8][4] These LSD prodrugs were developed byLizard Labs and emerged as noveldesigner drugs starting in the mid-2010s.[9][8][4][20][21] ALD-52 itself was first definitely encountered as a novel designer drug inEurope in 2016.[18][4][19] Soon thereafter, it was encountered inJapan andBrazil.[18][35][36] The detection of 1P-LSD slightly preceded that of ALD-52, having been first encountered in 2015.[27] ALD-52 was thought to act as a prodrug of LSD since at least the 1960s.[22][1] However, this was not definitely confirmed until formal studies were done in the 2010s and 2020s.[8][4][5][23]
ALD-52 is not listed as an illegal substance in Denmark as of April 2019, and its chemical class 'lysergamide' is not banned under the Analogue Act (some LSD analogues are, however, prohibited).[37]
ALD-52 is controlled under the NpSG as of July 18, 2019.[39][40] Production and import with the aim to place it on the market, administration to another person and trading is punishable. Possession is illegal but not penalized.[41]
ALD-52 is illegal in Latvia. Although it is not officially scheduled, it is controlled as an LSD structural analog due to an amendment made on June 1, 2015.[42]
ALD-52 is illegal to produce or sell in Romania. It is not included directly in the list of controlled substances, but it is included inan analogue act. However, it is not, as of yet, classified as illegal to use.
ALD-52 is a class A controlled drug, and is illegal to traffic, manufacture, import, export, possess, or consume in Singapore as of December 1, 2019, punishable with a minimum of five years' imprisonment and five strokes of the cane.[43]
ALD-52 is unscheduled in the United States. It may be considered an analogue of LSD, a Schedule I drug under the Controlled Substances Act. As such, the sale for human consumption or the use for illicit non-medical or scientific use could be prosecuted as crimes under theFederal Analogue Act however could be legal for medical and research uses like aresearch chemical.[45]
^abcdefghijklmnopqrsShulgin A,Shulgin A (September 1997).TiHKAL: The Continuation.Berkeley, California:Transform Press.ISBN0-9630096-9-9.OCLC38503252. "ALD-52. 1-Acetyl-N,N-diethyllysergamide. This material has been explored in the 50-175 microgram range and there are a number of human trials reported, with varying conclusions. One found that there was less visual distortion than with LSD and it seems to produce less anxiety and was somewhat less potent than LSD. Another report claimed it was more effective in increasing blood pressure. Yet another could not tell them apart. ALD-52 just may have been the drug that was sold as "Orange Sunshine" during the "Summer of Love" in the late '60's. Or "Orange Sunshine" may have been, really, LSD. This was the focus of a fascinating trial where two defendants were accused of distributing LSD, whereas they claimed that it was ALD-52 which was not an illegal drug. The prosecution claimed that as it hydrolyses readily to LSD, for all intents and purposes it was LSD, and anyway, you had to go through the illegal LSD to get to ALD-52 by any of the known chemical syntheses. The defendants were found guilty. And yet, I do not know who has actually measured the speed or ease of that reaction. If ALD-52 hydrolyses so easily to LSD, and the body is indeed a hydrolytic instrument, then these two drugs should be absolutely equivalent in every particular. This is the ergot equivalent of the psilocybin to psilocin argument, except this is an acetamide rather than a phosphate ester."
^abcdefghijklmnopqrstuvwxyzaaabacadaeafagHalberstadt AL, Chatha M, Klein AK, McCorvy JD, Meyer MR, Wagmann L, et al. (August 2020)."Pharmacological and biotransformation studies of 1-acyl-substituted derivatives of d-lysergic acid diethylamide (LSD)".Neuropharmacology.172 107856.doi:10.1016/j.neuropharm.2019.107856.PMC9191647.PMID31756337.The preparation of ALD-52 was first reported by Troxler and Hofmann in 1957 (Troxler and Hofmann, 1957). Tests of ALD-52 in human subjects revealed that it produces LSD-like effects and closely matches the time-course of LSD (Rothlin, 1957; Abramson, 1959; Isbell et al., 1959; Malitz et al., 1960). According to Rothlin (1957), both LSD and ALD-52 are active at doses of 0.5–1 μg/kg, but further experimental details were not provided. Abramson (1959) found ALD-52 to be 91% as potent as LSD, whereas Isbell et al. (1959) reported that the two substances are equipotent. In another study conducted in normal subjects and psychotic patients, LSD and ALD-52 produced similar effects, but the latter compound seemed to alter cognition and body image to a greater extent than LSD (Malitz et al., 1960). Although claims have been made that some of the LSD distributed during the late 1960s was actually ALD-52 (Tendler and May 1984), the first confirmed detection of the drug on the illicit market occurred in April 2016 (EMCDDA, 2017).
^abcdefghijklFanchamps A (1978)."Some Compounds With Hallucinogenic Activity". In Berde B, Schild HO (eds.).Ergot Alkaloids and Related Compounds. Handbook of Experimental Pharmacology (HEP). Vol. 49. Berlin, Heidelberg: Springer Berlin Heidelberg. pp. 567–614.doi:10.1007/978-3-642-66775-6_8.ISBN978-3-642-66777-0. Archived fromthe original on 30 March 2025.1-Acetyl-LSD (ALD 52, No. 36f) is as effective as LSD as a psychotomimetic. MALITZ et al. (1960, 1962) compared the effects of LSD (0.1–2.8 μg/kg) and ALD 52 (0.6–3.3 μg/kg) in a large series of subjects and psychotic patients; they found very similar action profiles, but ALD 52 produced somewhat more distortions of the body image and thinking disturbances. ABRAMSON (1959) rates its relative effectiveness at 91%, ISBELL et at. (1959a) at 100% of LSD. As a serotonin antagonist, it is 2.1 times more active than LSD on the isolated rat uterus (CERLETTI and DOEPFNER, 1958a), and upon intracerebral injection in mice, it produces the same excitatory syndrome and serotonin inhibition as LSD and MLD41 (HALEY, 1957). On the other hand, it has only a modest pyretogenic effect in the rabbit, amounting to 13% of the LSD activity (Sandoz Res. Lab., 1958).
^abcdefghiElliott SP, Holdbrook T, Brandt SD (May 2020). "Prodrugs of New Psychoactive Substances (NPS): A New Challenge".Journal of Forensic Sciences.65 (3):913–920.doi:10.1111/1556-4029.14268.PMID31943218.A biotransformation has been observed in lysergamides acylated at the indole nitrogen that in turn produces the corresponding "core" drug of LSD or ETH-LAD (52). Therefore, 1P-LSD, 1B-LSD, and ALD-52 are all prodrugs of LSD and 1PETH-LAD is a prodrug of ETH-LAD. All of these drugs have been discussed in Internet drug forums and are currently available for purchase online (53–56). Although ALD-52 was known to be psychoactive in humans for a long time (57), the formation of LSD both in vitro and in vivo (rats) has only been confirmed recently (51,57).
^Nichols DE (October 2018). "Dark Classics in Chemical Neuroscience: Lysergic Acid Diethylamide (LSD)".ACS Chemical Neuroscience.9 (10):2331–2343.doi:10.1021/acschemneuro.8b00043.PMID29461039.
^abcdZhang SH, Tang AS, Chin RS, Goh JY, Ong MC, Lim WJ, et al. (May 2023). "Stability studies of ALD-52 and its homologue 1P-LSD".Journal of Forensic Sciences.68 (3):1009–1019.doi:10.1111/1556-4029.15224.PMID36779453.ALD-52 was first synthesized and reported in 1957 by Hofmann et al., and its psychoactive effects were studied back in the 1950s and 1960s [16–18].
^abcdefghWalker C (31 October 2017)."Acid Trip: Denver's Secret LSD Labs Fueled the Psychedelic Revolution".Denver Westword. Retrieved3 November 2025.In April 1973, Sand and Scully were indicted by a federal grand jury and charged with income-tax evasion and conspiracy to produce and distribute LSD. During their trial, which began in October that year, they drew the ire of Judge Samuel Conti when they lied on the stand, saying they'd been trying to make a close relative of LSD: ALD-52, which was still legal. They even had a friend make some ALD-52, then pretend to have dug it up from an old stash that Scully and Sand had "buried." The tablets were ready just before Scully took the witness stand, so he didn't have a chance to try them ahead of time. When the government's chemist tested the substance, it presented as LSD. "That's when we learned, boys and girls, that ALD-52 is very unstable and will decompose into LSD at the blink of an eye," says Scully, who adds that he regrets lying to the judge. Scully was sentenced to twenty years in federal prison, and Sand received fifteen years.
^abcdeKavanagh PV, Westphal F, Pulver B, Elliott SP, Stratford A, Halberstadt AL, et al. (January 2025)."Analytical and behavioral characterization of 1-dodecanoyl-LSD (1DD-LSD)".Drug Testing and Analysis.17 (1):101–109.doi:10.1002/dta.3691.PMC11730435.PMID38569566.The extent to which ALD-52 circulated on the recreational drug market during the 1960s and the decades that followed is not clear. Claims have been made that LSD distributed under the name "orange sunshine" in the United States during the 1970s was actually ALD-52, although this has been disputed. The first confirmed detection of ALD-52 as a recreational drug appears to have occurred in Europe in 2016, when ALD-52 was reported to the European Monitoring Centre for Drugs and Drug Addiction as a new psychoactive substance (NPS).10 Detections of ALD-52 in Japan and Brazil were subsequently reported in the scientific literature.11–13
^abChiara JB (27 July 2022)."LSD light : Gobe, c'est du légal !" [LSD Light: Swallow It, It's Legal!].Technikart (in French). Retrieved29 September 2025.Sorti du labo hollandais Lizard Labs, cet acide est l'œuvre d'un chimiste qui contourne la loi en modifiant la structure moléculaire des substances. Dès 2015, il crée le 1P-LSD, ce qu'on appelle un « research chemical » (RC), qui n'est pas destiné à être consommé, mais étudié… [...] Nous sommes entrés en contact avec cet artiste de la molécule, l'un des seuls dans le monde à fabriquer du LSD en quantité industrielle, qui se décrit comme « entrepreneur, chimiste, ingénieur, penseur, bricoleur… peut-être artiste, je ne suis pas sûr de celui-là. ». Il nous explique : « J'ai créé le 1P-LSD car je crois que les psychédéliques devraient être accessibles à tous ceux qui veulent les explorer. Ce sont des outils très utiles pour sonder la psychologie humaine et le fonctionnement de la conscience. Le 1P-LSD a été la première substance que j'ai inventée, et une découverte assez fortuite, je ne m'attendais pas à ce qu'il fonctionne aussi bien ». Si le 1P-LSD est un secret de polichinelle en 2015, le plan se fait connaître en Allemagne vers la fin de la décennie. Avant qu'une loi allemande ne l'interdise en 2019, suivie par une loi française en 2020. Mais notre chimiste militant, ce résistant de l'ouverture des conscience, répond instantanément à ce « ban », et crée alors une nouvelle substance dès la fin 2019 : le 1cP-LSD. [...]
^abWagmann L, Richter LH, Kehl T, Wack F, Bergstrand MP, Brandt SD, et al. (July 2019). "In vitro metabolic fate of nine LSD-based new psychoactive substances and their analytical detectability in different urinary screening procedures".Analytical and Bioanalytical Chemistry.411 (19):4751–4763.doi:10.1007/s00216-018-1558-9.PMID30617391.
^Malitz S, Wilkens B, Roehrig WC, Hoch PH (April 1960). "A clinical comparison of three related hallucinogens".The Psychiatric Quarterly.34 (2):333–345.doi:10.1007/BF01562113.PMID13765819.
^abBrandt SD, Kavanagh PV, Westphal F, Stratford A, Elliott SP, Dowling G, et al. (August 2019)."Return of the lysergamides. Part V: Analytical and behavioural characterization of 1-butanoyl-d-lysergic acid diethylamide (1B-LSD)".Drug Testing and Analysis.11 (8):1122–1133.doi:10.1002/dta.2613.PMC6899222.PMID31083768.Various substitutions on the indole nitrogen (position N1 ) of LSD were prepared in previous decades, including the attachment of acyl groups.6,7 One of the earliest examples is 1‐acetyl‐LSD (ALD‐52, 1A‐ LSD; Figure 1), which has LSD‐like psychoactive properties in humans.8-11 It was recently shown that ALD‐52 is hydrolyzed to LSD when incubated with pooled human liver enzymes, indicating that it may serve as a prodrug for LSD in vivo.12 Clinical investigations with ALD‐52 are ultimately necessary to confirm the extent of LSD formation in humans. According to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), ALD‐52 was first detected in Europe in April 201613 whereas the detection of 1‐propanoyl‐LSD (1P‐LSD, Figure 1) was notified in 2015.14
^abJohnson MP, Audia JE, Nissen JS, Nelson DL (August 1993). "N(1)-substituted ergolines and tryptamines show species differences for the agonist-labeled 5-HT2 receptor".European Journal of Pharmacology.239 (1–3):111–118.doi:10.1016/0014-2999(93)90983-o.PMID8223886.
^Corne SJ, Pickering RW (1967). "A possible correlation between drug-induced hallucinations in man and a behavioural response in mice".Psychopharmacologia.11 (1):65–78.doi:10.1007/BF00401509.PMID5302272.
^Kozlenkov A, González-Maeso J (2013). "Animal Models and Hallucinogenic Drugs".The Neuroscience of Hallucinations. New York, NY: Springer New York. pp. 253–277.doi:10.1007/978-1-4614-4121-2_14.ISBN978-1-4614-4120-5.In the group of non-hallucinogens structurally similar to tryptamines or phenethylamines, the only "false negative" result was obtained with ALD ( N -acetyl-LSD), which, while known to be as active hallucinogen as LSD, did not produce head-twitches in mice, which was suggested, however, to be due to differences in metabolism between mice and humans.
^abcdNormand B (21 January 2017)."Cosmo Feilding Mellen: Interview with a Sunshine Maker".Psymposia. Retrieved3 November 2025.Was Orange Sunshine LSD or ALD-52? Was this the legal loophole Scully found to briefly get out of prison? No. That was a loophole that he tried to use in the trial, and it actually got him a worse prison sentence because he was lying to the court!
^Junior LF, Fabris AL, Barbosa IL, de Carvalho Ponce J, Martins AF, Costa JL, et al. (December 2022). "Lucy is back in Brazil with a new dress".Forensic Science International.341 111497.doi:10.1016/j.forsciint.2022.111497.PMID36283279.
