The skeletal formula of LSD
Chemical Nomenclature
Common names LSD, Acid, Lucy
Substitutive name Lysergic acid diethylamide
Systematic name (6aR,9R)-N,N-diethyl-7-methyl-4,6,6a,7,8,9-hexahydroindolo-[4,3-fg]quinoline-9-carboxamide
Class Membership
Psychoactive class Psychedelic
Chemical class Lysergamide
Routes of Administration

WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.
DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.
Threshold 25 - 50 µg
Light 50 - 75 µg
Common 75 - 200 µg
Strong 200 - 400 µg
Heavy 400 µg +
Total 6.5 - 13 hours
Onset 20 - 60 minutes
Come up 15 - 30 minutes
Peak 3 - 6 hours
Offset 3 - 5 hours
After effects 2 - 5 hours

Summary sheet: LSD

Lysergic acid diethylamide (abbreviated LSD or LSD-25 and also known as lysergide, acid or Lucy) is a semisynthetic hallucinogenic psychedelic drug of the lysergamide family.

LSD was first synthesized by Albert Hofmann in 1938 from ergotamine, a chemical derived from ergot (a grain fungus that typically grows on rye). The short form "LSD" comes from its early code name LSD-25 which is an abbreviation for the German "Lysergsäure-diethylamid" followed by a sequential number.[1]

LSD is sensitive to oxygen, ultraviolet light, and chlorine[2] (especially in solution). Its potency may last for years if it is stored away from light and moisture at cold temperatures around 0°C or below, but will slowly degrade at normal room temperature (25°C). In one study, there was a 10% loss of potency after LSD was stored at room temperature for one month.[3] However, there are also many anecdotal reports from users who have successfully stored LSD at room temperature for years which contradict the findings of this study.


LSD, or d-lysergic acid diethylamide, is a semi-synthethic alkaloid of the lysergamide famiy. LSD contains a core structure of lysergic acid, with an N,N-diethylamide functional group bound to RN of the chemical structure. This core polycyclic structure of LSD is an indole derivative, and has tryptamine and phenethylamine groups embedded within it.

LSD's structure contains a bicyclic hexahydroindole fused to a bicyclic quinoline group (lysergic acid). At carbon 8 of the quinoline a N,N-diethyl carboxamide is bound, LSD is additionally substituted at carbon 6 with a methyl group. LSD is a chiral compound with two stereocenters at R5 and R8. LSD, also called (+)-D-LSD, has an absolute configuration of (5R, 8R).

The three other stereoisomers of LSD do not have psychoactive properties.[4]


Binding affinities of LSD for various receptors. The lower the dissociation constant (Ki), the more strongly LSD binds to that receptor (i.e. with higher affinity). The horizontal line represents an approximate value for human plasma concentrations of LSD, and hence, receptor affinities that are above the line are unlikely to be involved in LSD's effect. Data averaged from data from the Ki Database.
This image shows how, with eyes-closed, much more of the brain contributes to the visual experience under LSD (right image) than under placebo (left image). The magnitude of this effect correlates with participants’ reports of complex, dreamlike visions.[5]

LSD acts as a 5-HT1A, 5-HT1A, 5-HT2A, 5-HT2B, 5-HT2C,and 5-HT6 receptor partial agonist.[6] LSD binds to most serotonin receptor subtypes except for 5-HT3 and 5-HT4. 5-HT5B receptors, which are not present in humans, also have a high affinity for LSD.[7] The psychedelic effects are believed to come from LSD's efficacy at the 5-HT2A receptors.[8]

There is also efficacy at all dopamine receptors and all adrenoreceptors. Most serotonergic psychedelics are not significantly dopaminergic, and LSD is therefore rather unique in this regard. LSD's agonism of D2 receptors contributes to its psychoactive effects.[9][10]

However, the role of these interactions and how they result in the psychedelic experience continues to remain elusive.

Subjective effects

The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. The listed effects will rarely (if ever) occur all at once, but heavier dosages will increase the chances and are more likely to induce a full range of effects.

Physical effects

  • Spontaneous tactile sensations - The "body high" of LSD can be described as proportionally very intense in comparison to its accompanying visual and cognitive effects. It behaves as a euphoric, fast-moving, sharp and location specific tingling sensation. For some it is manifested spontaneously at different unpredictable points throughout the trip, but for most it maintains a steady presence that rises with the onset and hits its limit once the peak has been reached. At moderate to high doses of LSD, this sensation will usually hit its highest level and become so overwhelming that users often find themselves writhing on the floor in complete pleasure.
  • Stimulation - In terms of its effects on the physical energy levels of the tripper, LSD is usually considered to be very energetic and stimulating without being forced. For example, when taken in any environment it will usually encourage physical activities such as running, walking, climbing or dancing. In comparison, other more commonly used psychedelics such as psilocin are generally sedating and relaxed.
  • Nausea - Mild nausea is occasionally reported when consumed in moderate to high dosages and either passes instantly once the tripper has vomited or gradually fades by itself as the peak sets in.
  • Muscle spasms
  • Tactile enhancement - Feelings of enhanced tactile sensations are consistently present at moderate levels throughout most LSD trips. Once level 8A geometry is reached, an intense sensation of suddenly becoming aware of and being able to feel every single nerve ending across a person's entire body all at once is consistently present.
  • Bodily control enhancement
  • Increased blood pressure - Occasionally in high doses or in uncomfortable settings this can lead to overheating or even hot flashes which often result in increased perspiration, however these outcomes are highly dependent on the set and setting and are for the most part uncommon.
  • Increased heart rate
  • Perception of decreased weight
  • Physical euphoria
  • Pupil dilation

Cognitive effects

The cognitive effects of LSD can be broken down into several components which progressively intensify proportional to dosage. In comparison to other psychedelics such as Psilocin, LSA and ayahuasca, LSD is significantly more stimulating and fast-paced in terms of the specific style of thought stream produced and contains a large number of potential effects.

The most prominent of these cognitive effects generally include:

Visual effects




The visual geometry that is present throughout this trip can be described as more similar in appearance to that of 2C-B or 2C-I than Psilocin, LSA or DMT. It can be comprehensively described through its variations as primarily intricate in complexity, algorithmic in form, unstructured in organization, brightly lit, colourful in scheme, synthetic in feel, multicoloured in scheme, flat in shading, sharp in edges, large in size, fast in speed, smooth in motion, angular in its corners, non-immersive in depth and consistent in intensity. At higher dosages, it almost consistently results in states of Level 8A visual geometry over Level 8B.

Hallucinatory states

LSD is capable of producing a full range of low and high level hallucinatory states in a fashion that is significantly less consistent and reproducible than that of many other commonly used psychedelics. These effects include:

Auditory effects

Multi-sensory effects

Combinational effects

  • Marijuana - When used in combination with cannabis, both the visual and the cognitive effects of LSD can be intensified and extended with extreme efficiency. This should be used with caution if one is not experienced with psychedelics. Many users sometimes report a dramatically more intense visual trip when combining it with THC concentrates such as hashish as opposed to cannabis flower.
  • Dissociatives - When used in combination with dissociatives, the geometry, euphoria, dissociation and hallucinatory effects are often greatly enhanced. Dissociative-induced holes, spaces and voids while under the influence of LSD have significantly more vivid visuals than dissociatives alone present, and more intense internal hallucinations and confusion.
  • MDMA - When used in combination with MDMA, the physical and cognitive effects of MDMA are amplified. The visual, physical and cognitive effects of LSD are also intensified with an overwhelming euphoric slant manifested through uniquely pleasurable body highs and headspaces, and uniquely colourful and awe-inspiring visuals. It is often advised to wait at least three hours after ingesting LSD to take MDMA so as to avoid coming down from the latter while peaking on the former, but positive experiences are reported with all possible timings. The synergy between these substances is unpredictable and it is recommended to start with lower dosages than one would take for both drugs individually.
  • Benzodiazepines - When in combination with benzodiazepines, benzodiazepines can, depending on dosage, slightly to completely reduce the intensity of the cognitive, physical and visual effects of an LSD trip. They are very efficient at stopping bad trips at the cost of amnesia and reduced trip intensity. Caution is advised as the addiction potential for benzodiazepines is very high.
  • Psychedelics - When used in combination with other psychedelics, each drug's physical, cognitive and visual effects intensify and synergize strongly. The synergy between those substances is unpredictable and it is recommended to start with lower dosages than one would take for either drug individually.


LSD can be found in a number of forms:

  • Liquid is often found in vials with a pipette. Liquid LSD is often dropped into the mouth or onto the tongue. There should not be a bitter metallic taste which numbs the mouth, as this instead indicates the presence of a 25x-NBOMe compound.
  • Tablets and "microdots" are very small tablets which are swallowed.
  • Blotters are sheets of blotting paper that are dipped into an LSD/alcohol solution which are then either swallowed or chewed sublingually. There should not be a bitter metallic taste which numbs the mouth when chewing the blotters as this instead indicates the presence of a 25x-NBOMe compound.
  • Powder can be taken orally, sublingually, via injection or by insufflation.
  • Gel tabs can be taken orally and are small pieces of gelatin which contain LSD. These have become less common, but are still occasionally present in some areas of the world.

Studied therapeutic uses


Some studies in the 1960s that used LSD to treat alcoholism resulted in reduced levels of alcohol misuse in almost 60% of those treated, an effect which lasted six months but disappeared after a year. [12][13] A 1998 review was inconclusive.[14] However, a 2012 meta-analysis of six randomized controlled trials found evidence that a single dose of LSD in conjunction with various alcoholism treatment programs was associated with a decrease in alcohol abuse, lasting for several months.[15]


LSD was studied in the 1960s by Eric Kast as an analgesic for serious and chronic pain caused by cancer or other major trauma.[16]

Even at low (sub-psychedelic) dosages, it was found to be at least as effective as traditional opiates, while being much longer lasting in pain reduction (lasting as long as a week after peak effects had subsided). Kast attributed this effect to a decrease in anxiety; that is to say that patients were not experiencing less pain, but rather were less distressed by the pain they experienced. This reported effect is being tested, though not using LSD, in an ongoing (as of 2006) study of the effects of psilocin on anxiety in terminal cancer patients.

Cluster headaches

LSD has been used as a treatment for cluster headaches, an uncommon but extremely painful disorder. Researcher Peter Goadsby describes the headaches as "worse than natural childbirth or even amputation without anesthetic."

Although the phenomenon has not been formally investigated, case reports indicate that LSD and psilocin can reduce cluster pain and also interrupt the cluster headache cycle, preventing future headaches from occurring. Currently existing treatments include various ergolines among other chemicals, so LSD's efficacy may not be surprising. A dose-response study testing the effectiveness of both LSD and psilocin was planned at McLean Hospital, although the current status of this project is unclear. A 2006 study by McLean researchers interviewed 53 cluster headache sufferers who treated themselves with either LSD or psilocin, finding that a majority of the users of either drug reported beneficial effects. [17]

Unlike use of LSD or MDMA in psychotherapy, this research involves non-psychological effects and often sub-psychedelic dosages.[18][19]

End-of-life anxiety

From 2008 to 2011 there was ongoing research in Switzerland into using LSD to alleviate anxiety for terminally ill cancer patients coping with their impending deaths. Preliminary results from the study are promising and no negative effects have been reported.[20][21]

Toxicity and harm potential

Radar plot showing relative physical harm, social harm, and dependence of LSD[22]

LSD is non-addictive, is not known to cause brain damage, and has an extremely low toxicity relative to dose.[23] Similar to other psychedelic drugs, there are relatively few physical side effects associated with acute LSD exposure. Various studies have shown that in reasonable doses in a careful context, it presents no negative cognitive, psychiatric or toxic physical consequences of any sort.

Lethal dosage

The median lethal dose or dosage at which 50% of participants die (LD50) for human beings has never been reached in any setting and is predicted to be roughly 12,000 micrograms, based on studies involving rats whereas the active dosage is between 100 and 500 micrograms. This means that assuming a person has unusually potent tabs, each of which are 200 micrograms in strength, they would have to consume at least 60 of them to reach a potentially lethal dosage. Keep in mind that the average tab of LSD found on through street dealers is perhaps 100 micrograms or less in strength.

It is strongly recommended that one use harm reduction practices when using this drug.

Tolerance and addiction potential

LSD is not habit-forming and the desire to use it can actually decrease with use. It is most often self-regulating.

Tolerance to the effects of LSD are built almost immediately after ingestion. After that, it takes about 3 days for the tolerance to be reduced to half and 7 days to be back at baseline (in the absence of further consumption). LSD presents cross-tolerance with all psychedelics, meaning that after the consumption of LSD all psychedelics will have a reduced effect.

Dangerous interactions

Although many drugs are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses of each but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.

Legal issues

  • International: The UN 1971 Convention on Psychotropic Substances requires its parties to prohibit LSD. Hence, it is illegal in all parties to the convention, which includes the United States, Australia, New Zealand, and most of Europe. Medical and scientific research with LSD in humans is permitted under the 1971 UN Convention.
  • Canada: LSD is a Schedule III drug.
  • UK: LSD is a Class A drug.
  • USA: LSD is a Schedule I drug.
  • Latvia: LSD is a Schedule I drug.[29]

Experience reports

Anecdotal reports which describe this compound within our experience index include:

Additional experience reports can be found here:

See also

External links


  1. LSD - My Problem Child by Albert Hoffman |
  2. Alexander and Ann Shulgin. "LSD", in TiHKAL -
  3. Stability Study of LSD Under Various Storage Conditions |
  5. LSD's impact on the brain revealed in groundbreaking images |
  7. 5-HT5 receptors ( / NCBI) |
  8. Metabotropic glutamate mGlu2 receptor is necessary for the pharmacological and behavioral effects induced by hallucinogenic 5-HT2A receptor agonists ( / NCBI) |
  9. Distinct temporal phases in the behavioral pharmacology of LSD: Dopamine D2 receptor-mediated effects in the rat and implications for psychosis ( / NCBI) |
  11. Lysergic acid diethylamide (LSD) for alcoholism: meta-analysis of randomized controlled trials ( / NCBI) |
  12. LSD "helps alcoholics to give up drinking" |
  13. Maclean, J.R.; Macdonald, D.C.; Ogden, F.; Wilby, E., "LSD-25 and mescaline as therapeutic adjuvants." In: Abramson, H., Ed., The Use of LSD in Psychotherapy and Alcoholism, Bobbs-Merrill: New York, 1967, pp. 407–426; Ditman, K.S.; Bailey, J.J., "Evaluating LSD as a psychotherapeutic agent," pp.74–80; Hoffer, A., "A program for the treatment of alcoholism: LSD, malvaria, and nicotinic acid," pp. 353–402.
  14. Treatment of alcoholism using psychedelic drugs: a review of the program of research |
  15. Lysergic acid diethylamide (LSD) for alcoholism: meta-analysis of randomized controlled trials |
  16. Attenuation of anticipation: a therapeutic use of lysergic acid diethylamide |
  17. Response of cluster headache to psilocin and LSD |
  18. Summarized from "Research into psilocin and LSD as cluster headache treatment" and the Clusterbusters website. Pages accessed 2007-01-31.
  19. Berlin pilot cluster headaches treatment with LSD study. LSD Alleviates 'Suicide Headaches'.
  20. Psychiater Gasser bricht sein Schweigen |
  21. Landmark Clinical LSD Study Nears Completion |
  22. Development of a rational scale to assess the harm of drugs of potential misuse (ScienceDirect) |
  23. The Pharmacology of Lysergic Acid Diethylamide: a Review |
  24. Dose-independent occurrence of seizure with tramadol - Springer |
  25. Tripsit Factsheets - LSD |
  26. Grand mal seizures following ingestion of LSD. -
  27. Question ID: 2837 (Ask Erowid) |
  28. Tripsit Factsheets - LSD |
  29. Noteikumi par Latvijā kontrolējamajām narkotiskajām vielām, psihotropajām vielām un prekursoriem (I saraksta 2.2.1.punkts) |