2,3-Dihydro-LSD, or 2,3-DH-LSD, also known as 2,3-dihydrolysergic acid diethylamide, is a

psychedelic drug Psychedelics are a subclass of hallucinogenic drugs whose primary effect is to trigger non-ordinary mental states (known as psychedelic experiences or "trips") and a perceived "expansion of consciousness". Also referred to as classic halluc ...

of the

lysergamide Lysergamides, also known as ergoamides or as lysergic acid amides, are amides of lysergic acid (LA). They are ergolines, with some lysergamides being found naturally in ergot as well as other fungi. Lysergamides are notable in containing embedd ...

family related to

lysergic acid diethylamide Lysergic acid diethylamide, commonly known as LSD (from German ; often referred to as acid or lucy), is a Semisynthesis, semisynthetic, Hallucinogen, hallucinogenic compound derived from ergot, known for its powerful psychological effects and ...

(LSD). It is the analogue of LSD in which the 2,3-

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

in the

indole Indole is an organic compound with the formula . Indole is classified as an aromatic heterocycle. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered pyrrole ring. Indoles are derivatives of indole ...

ring (The) Ring(s) may refer to: * Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry * To make a sound with a bell, and the sound made by a bell Arts, entertainment, and media Film and TV * ''The Ring'' (franchise), a ...

within the

ergoline Ergoline is a core structure in many alkaloids and their synthetic derivatives. Ergoline alkaloids were first characterized in ergot. Some of these are implicated in the condition of ergotism, which can take a convulsive form or a gangrenous for ...

ring system A ring system is a disc or torus orbiting an astronomical object that is composed of solid material such as dust, meteoroids, planetoids, moonlets, or stellar objects. Ring systems are best known as planetary rings, common components of sate ...

has been

hydrogenated Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organi ...

Use and effects

The drug produces similar autonomic and

psychoactive A psychoactive drug, psychopharmaceutical, mind-altering drug, consciousness-altering drug, psychoactive substance, or psychotropic substance is a chemical substance that alters psychological functioning by modulating central nervous system acti ...

effects as LSD in humans, although its

hallucinogen Hallucinogens, also known as psychedelics, entheogens, or historically as psychotomimetics, are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mo ...

ic effects are less pronounced. It has been found to possess about one-sixth to one-eighth (i.e., ~15% overall) of the

potency Potency may refer to: * Potency (pharmacology), a measure of the activity of a drug in a biological system * Virility * Cell potency, a measure of the differentiation potential of stem cells * In homeopathic dilutions, potency is a measure of ho ...

of LSD in inducing

mydriasis Mydriasis is the Pupillary dilation, dilation of the pupil, usually having a non-physiological cause, or sometimes a physiological pupillary response. Non-physiological causes of mydriasis include disease, Physical trauma, trauma, or the use of c ...

(pupil dilation) and

psychedelic Psychedelics are a subclass of hallucinogenic drugs whose primary effect is to trigger non-ordinary mental states (known as psychedelic experiences or "trips") and a perceived "expansion of consciousness". Also referred to as classic halluci ...

effects, respectively, in humans. More specifically, 2,3-dihydro-LSD is psychedelic at doses of 3.0 to 4.5μg/kg (210–315μg for a 70-kg person), while LSD is hallucinogenic at doses of 0.5 to 1.0μg/kg (35–70μg for a 70-kg person). In addition to its greatly reduced potency compared to LSD, 2,3-dihydro-LSD has a delayed onset and time to peak effects relative to LSD. The duration of 2,3-dihydro-LSD was roughly 8 to 12hours and was longer than that of LSD (which had a duration of about 7hours in the study) as well.

Pharmacology

Pharmacodynamics

In rabbits, 2,3-dihydro-LSD had about 4% (1/25th) of the potency of LSD in inducing

hyperthermia Hyperthermia, also known as overheating, is a condition in which an individual's body temperature is elevated beyond normal due to failed thermoregulation. The person's body produces or absorbs more heat than it dissipates. When extreme te ...

, while in mice, it was "equally

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...

" (presumably referring to ) as LSD.

Pharmacokinetics

It is possible that 2,3-dihydro-LSD may function as a

prodrug A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be ...

and aromatize/ dehydrogenate into LSD or

metabolize Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the ...

into another

active metabolite An active metabolite, or pharmacologically active metabolite is a biologically active metabolite of a xenobiotic substance, such as a drug or environmental chemical. Active metabolites may produce therapeutic effects, as well as harmful effects. ...

in vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, an ...

''. Relatedly, 2,3-dihydroindoles can be fairly readily aromatized into

s, and 2,3-dihydro-LSD has been detected as a metabolite of

radiolabel A radioactive tracer, radiotracer, or radioactive label is a synthetic derivative of a natural compound in which one or more atoms have been replaced by a radionuclide (a radioactive atom). By virtue of its radioactive decay, it can be used to exp ...

ed LSD in the isolated perfused rat

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'', supporting the possibility of interconversion between the two compounds. Alternatively, 2,3-dihydro-LSD might be absorbed more slowly or penetrate the

blood–brain barrier The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...

more gradually than LSD.

History

2,3-Dihydro-LSD was first described in the

scientific literature Scientific literature encompasses a vast body of academic papers that spans various disciplines within the natural and social sciences. It primarily consists of academic papers that present original empirical research and theoretical ...

by Charles Gorodetzky and Harris Isbell at the Addiction Research Center of the

National Institute of Mental Health The National Institute of Mental Health (NIMH) is one of 27 institutes and centers that make up the National Institutes of Health (NIH). The NIH, in turn, is an agency of the United States Department of Health and Human Services and is the primar ...

(subsequently part of the

National Institute on Drug Abuse The National Institute on Drug Abuse (NIDA) is a United States federal government research institute whose mission is to "advance science on the causes and consequences of drug use and addiction and to apply that knowledge to improve individual ...

) by 1964. However, it had first been synthesized and studied in animals by Botand Berde and Rudolph Bircher at Sandoz Pharmaceuticals, but their findings were unpublished. Sandoz Pharmaceuticals supplied the 2,3-dihydro-LSD used by Gorodetzky and Isbell in their clinical study.

References

External links

2,3-Dihydro-LSD - Isomer Design
{{Ergolines Diethylamino compounds Enantiopure drugs Lysergic acid diethylamide Psychedelic lysergamides