LSD Substance Guide

Here’s your ultimate LSD guide to everything you need to know about about the substance. Wondering how this powerful substance works in the brain to create profound changes in consciousness and potentially enhance mental health? Let’s dive into its fascinating history and the groundbreaking research behind it!

Drug Class

Lysergic acid diethylamide (LSD) is a synthetic compound classified under the ergoline family, a group of chemical structures derived from ergot alkaloids. Known for its profound psychoactive effects, LSD is a prominent example of classical psychedelics. This category also includes naturally occurring substances like psilocybin (found in certain species of mushrooms) and N,N-Dimethyltryptamine (DMT), which is present in various plants.

What is LSD?

As a classical psychedelic, LSD interacts primarily with serotonin receptors in the brain, particularly the serotonin 2A (5-HT2A) receptor, leading to its characteristic effects. These effects often include altered perception, vivid visual imagery, intensified emotions, and a sense of expanded consciousness. LSD has a uniquely high potency, with efficacious doses measured in micrograms, making it one of the most potent psychoactive substances known.

Synthesized for the first time in 1938 by Swiss chemist Dr. Albert Hofmann, LSD gained widespread attention in the mid-20th century for its potential in psychiatric research, spiritual exploration, and creative endeavors. Despite its therapeutic promise, the compound’s controversial history and association with countercultural movements led to strict regulatory controls in many countries. The United States currently classifies LSD as a Schedule 1 controlled substance, and most countries classify it as illegal. Today, LSD is undergoing a resurgence in scientific studies exploring its potential for treating mental health conditions such as depression, anxiety, and PTSD, as well as its role in facilitating personal and spiritual growth.

LSD, also known as acid, is consumed through different mediums, including blotter paper, tablets, and liquid. You can watch this short video from the MIND Foundation that gives an overview of LSD:

LSD History and Law

LSD is derived from ergot alkaloids, natural compounds produced by the ergot fungus, primarily infecting rye and related grains. The Swiss Chemist Albert Hofmann first synthesized LSD in 1938 while he was working to isolate ergobasine, a compound found in ergot with potential medical applications. During his experiments, Hofmann synthesized a substance he labeled LSD-25, as it was the 25th compound in a series of lysergic acid derivatives.

For several years, LSD-25 remained largely overlooked until Hofmann revisited it in 1943. During this renewed investigation, he accidentally absorbed a small amount of the substance through his skin and experienced its powerful psychoactive effects. Intrigued by this unexpected discovery, Hofmann decided to conduct a deliberate self-experiment on April 19, 1943. This experiment marked the first intentional use of LSD and coincided with a bicycle ride home from his laboratory, during which he experienced the drug’s intense effects. This historic event is now celebrated annually as “Bicycle Day,” commemorating the moment Hofmann fully realized LSD’s unique properties.

Albert Hoffman, in his infamous book LSD – My Problem Child, describes his experience as:

“I suddenly became strangely inebriated. The external world became changed as in a dream. Objects appeared to gain in relief; they assumed unusual dimensions, and colors became more glowing. Even self-perception and the sense of time were changed. When the eyes were closed, colored pictures flashed past in a quickly changing kaleidoscope. After a few hours, the not unpleasant inebriation, which had been experienced whilst I was fully conscious, disappeared. What had caused this condition?”

Early Scientific Exploration of LSD

LSD garnered significant interest from scientists and therapists during the late 1940s and 1950s. In its early research phase, numerous clinical trials and experiments explored its effects, revealing promising potential applications in psychotherapy. Researchers observed that LSD could facilitate breakthroughs in treating mental health conditions such as depression, anxiety, and addiction, as well as enhance self-awareness and emotional processing in patients.

“What fuels this renaissance, in part, is a broader societal shift toward reexamining psychedelics as tools for healing rather than mere recreational substances…Promising early results suggest that LSD…could offer transformative benefits for individuals struggling with a range of mental health challenges.”

However, beyond its medical and therapeutic uses, LSD gained widespread popularity within the counterculture movement of the 1960s. It became emblematic of the era’s exploration of consciousness and was widely used for recreational purposes, often associated with art, music, and spiritual experiences. The growing prevalence of LSD in mainstream society, coupled with concerns about its misuse and societal impact, led to its criminalization. In 1968, the United States classified LSD as a Schedule I drug, signifying its prohibition and labeling it as a substance with no accepted medical use and a high potential for abuse. This designation effectively halted scientific research on LSD for decades, although recent years have seen renewed interest in studying its therapeutic potential.

Historical Timeline of LSD

• 1938: Chemist Albert Hoffmann synthesized LSD on November 16, 1938, while employed at the Sandoz Laboratories in Basel, Switzerland.
• 1943: Albert Hoffmann accidentally ingested 250 micrograms of LSD on April 19, 1943, and became the first person to experience the drug’s psychedelic effects.
• 1943: Susi Ramstein, laboratory assistant to Dr. Hofmann, became the first woman to ingest LSD on June 12, 1943, and was acknowledged as the first psychedelic guide.
• 1947: Sandoz introduced LSD (brand name Delysid©) as a drug for model psychosis, then later investigated it for psychotherapeutic purposes.
• 1950s: LSD was used in psychiatry with therapeutic modalities (psycholytic or psychedelic therapy) and administered to thousands of people, specifically for disorders such as alcoholism.
• 1960s: LSD became a widely used recreational drug and was associated with counterculture and anti-war movements.
• 1968: The US government outlawed LSD, making drug possession illegal and stopping clinical research.
• 1990s to present day: The therapeutic potential of psychedelic substances, including LSD, gained renewed attention among scientists and therapists. Ongoing clinical trials are investigating the safety and efficacy of LSD to treat mental health conditions.

Pharmacology of LSD

From a pharmacological perspective, LSD exhibits unique properties compared to other serotonergic psychedelics. While it primarily interacts with serotonin receptors, particularly the 5-HT2A receptor—widely recognized as the primary mediator of psychedelic effects—LSD’s activity extends beyond this single pathway. It also binds to serotonin 2C and 1A receptors and modulates several other neurotransmitter systems, including dopaminergic, adrenergic, and glutamatergic.

This multi-receptor activity contributes to LSD’s complex and conscious-altering effects. The interaction with dopamine receptors may enhance its stimulating properties. At the same time, the modulation of adrenergic and glutamate systems likely plays a role in its ability to alter perception, cognition, and emotional states. These combined pharmacological actions make LSD distinct within the family of classical psychedelics and help explain its profound and multifaceted effects on the brain and consciousness.

Dosage, Effects, and Tolerance

A single dose of LSD is measured in micrograms and administered orally. A moderate dose is considered to range from 75 to 150 micrograms (μg), while a microdose (sub-perceptual) is 5 to 10 micrograms (μg). Most people can detect LSD’s effects at 25 μg, but subtle changes in mood or cognition may be noticeable at the microdose range. The acute psychoactive effects of LSD emerge after 20-90 minutes and last between 6 to 12 hours, depending on the dose, as well as the tolerance, weight, and age of the user.

Similar to other classical psychedelics, LSD is not associated with physical dependence or withdrawal symptoms. Repeated use quickly leads to the development of tolerance, meaning that the drug’s effects diminish with frequent use over a short period. This rapid tolerance, which typically reverses after a few days of abstinence, discourages compulsive use, leading experts to exclude LSD from the category of addictive substances.

In terms of toxicity, researchers consider LSD safe when used in controlled settings, as it has an extremely low physiological toxicity and does not cause damage to organs—even at high doses. No human deaths have been attributed to LSD overdose. However, while the compound itself is not inherently harmful, its psychological effects can be profound and unpredictable, particularly in unprepared individuals or uncontrolled environments.

Adverse psychological reactions, such as acute anxiety or distress (“bad trips”), can occur, especially at higher doses or in those with underlying mental health conditions. Nevertheless, with appropriate precautions, LSD is generally regarded as having a favorable safety profile compared to many other psychoactive substances. If you are curious about the history, discovery, and pharmacology of LSD, please read The Pharmacology of LSD: A Critical Review by Annelie Hintzen and Torsten Passie.

How does LSD Work in the Brain?

Neurological Mechanisms of LSD

The effects of psychedelics on neurological function are both fascinating and complex. But what exactly happens in the brain after you take LSD?

When LSD enters the brain, it acts primarily as a partial agonist at serotonin receptors, particularly the 5-HT2A receptor subtype. These receptors are crucial for the effects of psychedelics and underlie the shifts in conscious awareness. By binding to and activating 5-HT2A receptors, LSD influences various signaling pathways in the brain, leading to time-bound changes in perception, cognition, and mood.

The activation of 5-HT2A receptors contributes to the hallmark effects of LSD, such as vivid hallucinations, visual distortions, and intricate kaleidoscopic patterns. These effects arise from temporarily altered neural activity in brain regions responsible for sensory processing, emotional regulation, and self-awareness. For instance, LSD is known to increase connectivity between typically-segregated brain networks, facilitating a “cross-talk” that may underlie experiences like synesthesia (e.g., “hearing” colors or “seeing” sounds). The effects on multiple neural networks underlie the experiences reported by users.

While these experiences can be transformative and therapeutic in controlled settings, they can also be overwhelming if taken in unsafe environments or without proper preparation. The interplay of LSD with the brain’s neural networks is a key area of ongoing research, shedding light on its potential for both enhancing self-awareness and addressing mental health conditions.

Videos Exploring LSD’s Effects on the Brain

For further information on LSD’s common effects, watch the videos below!

This video explains LSD and its common alterations on the brain:

2-minute neuroscience of LSD that summarises the information above:

LSD can change the brain’s connectivity and open new neuronal communication pathways. In this video, Prof. Dr. David

We also recommend this video that illustrates the brain scan and the connected brain regions on LSD:

Subjective and Therapeutic Effects of LSD

The experiences on LSD are pretty subjective and differ significantly from person to person and even from trip to trip in a single individual. Although we understand how LSD binds to receptors in the brain, individual experiences and their contribution to therapeutic outcomes are still not fully understood. However, the most common positive, adverse, and psychological effects are well established from both research studies and recreational uses. Let’s explore how LSD impacts perception, mood, and emotions.

Psychological and Emotional Effects

LSD induces profound alterations in consciousness, creating non-ordinary states often characterized by heightened awareness and an expanded perception of oneself and the universe. The most common effects include significant changes in emotions and thought processes and an enhanced sensory experience of the surrounding environment.

When discussing psychedelic drugs, the term hallucinations frequently arises. However, LSD’s effects often go beyond traditional hallucinations and are better described as sensory distortions and visual alterations. These can include vivid imagery, intricate patterns, and dynamic shifts in colors and shapes, often experienced with eyes open or closed.

Many individuals report additional effects beyond the sensory domain. These include:

• Enhanced Connectedness: A profound sense of unity with nature, others, or the universe as a whole.
• Openness: A greater willingness to explore new ideas, perspectives, and emotions.
• Positive Emotional States: Individuals commonly describe feelings of euphoria, love, and empathy.
• Mystical Experiences: Intense spiritual or transcendental experiences, often described as deeply meaningful or life-changing.

The ability of LSD to amplify sensory perceptions and evoke deeply personal insights has made it a subject of interest for both scientific research and therapeutic applications. In controlled settings, therapists and researchers often leverage these effects to foster emotional healing, self-discovery, and a greater sense of connectedness.

LSD can induce a variety of psychological and emotional effects beyond its more commonly noted impacts. These may include changes in sensations and feelings, experiences of synesthesia, an altered sense of self, and shifts in the perception of time and space. Individuals might also encounter confusion, heightened emotional awareness, or profound mystical and spiritual experiences. Additionally, LSD is known to enhance creativity and introspection and can also potentially cause rapid mood changes.

Positive Effects of LSD

LSD can produce a wide range of pleasurable and positive effects. Among the most common are vivid imagery (experienced with open or closed eyes), euphoria, insightfulness, and captivating sensory experiences. Additionally, LSD often fosters increased creativity, imaginative thinking, and a profound sense of unity and connectedness with others, nature, and the universe. Many individuals report experiencing ego dissolution, which can be perceived as either positive or negative, alongside deeply spiritual or mystical encounters. These effects frequently lead to life-changing insights and transformative personal revelations.

Negative Effects of LSD

LSD is a highly context-dependent drug, and the intensity of the experience is closely related to pharmacological and non-pharmacological factors, which we name “set” and “setting.” While “set” refers to one’s internal mindset—personality, preparation, intention, and brain chemistry—“setting” refers to the physical, social, and cultural environment where users take the drug. Both the set and setting significantly play into the experience.

Ensuring a proper set and setting—such as a safe environment, a calm mindset, and trusted support—can help minimize the risk of adverse reactions. However, individuals with a history of contraindicated mental health issues or susceptibility to psychosis are generally excluded from participation in psychedelic clinical trials, as these substances can significantly amplify psychological risks.

Potential Risks and Adverse Effects of LSD

LSD can induce adverse effects and challenging experiences. The most common negative effects include anxiety, paranoia, flashbacks, disordered thinking, confusion, and irrational behavior. Challenging and overwhelming experiences, so-called “bad trips,” can be very intense and provoke significant distress and anxiety. These experiences can impact psychological well-being, with short-term effects such as confusion or fear and, in some cases, longer-term negative outcomes on mental well-being.

LSD, like other psychedelics, can potentially precipitate or worsen underlying psychological conditions in vulnerable individuals. It may lead to psychotic symptoms, including paranoia, delusions, mania, or depression, especially in those with a predisposition to specific mental health disorders like schizophrenia. For this reason, caution is essential when using LSD, particularly outside of a controlled or medically supervised setting.

LSD can lead to a variety of adverse psychological and physiological effects. These include dysphoria, loss of appetite, dilated pupils, and fluctuations in blood pressure or body temperature. Some individuals may experience insomnia, panic attacks, fear, anxiety, or paranoia. Physical coordination and reaction times can also become impaired, along with decreased attention and concentration. Other reported effects include nausea, vomiting, mild headaches, dizziness, and alterations in body processes, such as changes in body image perception.

Contraindicated Medications and Conditions

LSD research trials always include a list of inclusion and exclusion criteria for participation, which ensures safety and study integrity. Common medical conditions that researchers generally screen for exclusion involve a history of seizure activity, stroke, or cardiovascular diseases, as well as chronic medical conditions or a history of head trauma. Individuals with a personal or family history of psychotic disorders are also typically excluded, along with those using psychoactive medications. Additionally, pregnant or lactating women are generally not eligible to participate in these trials.

The exact mechanism of LSD and drug interactions is not entirely understood. However, there are some medications that may increase the risk of adverse effects.

Some medications can alter the response to LSD and its subjective effects. For instance, benzodiazepines—such as Xanax, Klonopin, Valium, and Ativan—can decrease the visual and cognitive effects of psychedelics.

According to this blog article published in MIND Foundation:

“Nevertheless, a close look at the effects of common antidepressants and psychedelic drugs on serotonin neurotransmission suggests that this combination is risky from a pharmacological point of view and that it would be very unlikely to have clinically beneficial effects. Consequently, caution is advised when considering taking a psychedelic while on antidepressant medication.”

Risk of Serotonin Syndrome

LSD, like other psychedelic substances, carries a potential risk of serotonin syndrome, a condition caused by overstimulation of serotonin receptors. This condition occurs when excessive serotonin activity leads to a range of symptoms that can affect the body physically, mentally, and neurologically.

Symptoms of serotonin syndrome may include:

• Physical: Elevated heart rate, high blood pressure, sweating, shivering, or fever.
• Neurological: Muscle rigidity, tremors, or twitching.
• Mental: Confusion, agitation, or hallucinations.

While the design of most antidepressants aims to modulate serotonin levels in the brain, LSD directly binds to serotonin receptors and can potentially contribute to serotonin syndrome when combined with other serotonergic drugs, such as selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors (MAOIs).

To mitigate the risk, individuals using LSD should avoid combining it with serotonergic medications or other substances that elevate serotonin levels. Although serotonin syndrome is rare, especially with LSD alone, it can become a serious medical condition if left untreated. Awareness and caution are key to preventing this risk.

Psychotherapeutic Applications of LSD: Psychedelic Therapy and Psycholytic Therapy

Research into the therapeutic potential of LSD began in the 1950s and flourished through the 1960s, gaining significant momentum during this period. Early studies primarily focused on understanding its dosing and physiological effects. Once researchers established the safety of LSD, they turned their attention to its applications in psychotherapy, known at the time as psycholytic or psychedelic therapy. LSD showed promise in treating a variety of conditions, including anxiety, depression, psychosomatic disorders, pain, anxiety in late-stage cancer, and addiction. However, trials of this era have been scrutinized based on the lack of today’s appropriate control conditions and rigorous standards.

In early research, European psychotherapists first coined the term psycholytic therapy in the 1950s to describe the administration of LSD. Psycholytic therapy includes low doses of the substance (50-100 mcg) in a series of LSD sessions for psychoanalytic purposes. Psychedelic therapy was used mainly by American researchers and therapists to describe administering large doses (250-500 mcg) once or a few times.

The video below gives you an overview of how psychedelic drugs, including LSD, can be used therapeutically.

Here, Prof.Dr. Roland Griffiths explains the therapeutic use of psychedelics and LSD:

Therapeutic Potential and Modern Research

In a therapeutic context, LSD has shown potential benefits for treating anxiety, depression, and addiction. Its applications may extend beyond these conditions. Research in the 1970s explored the use of LSD for psychosomatic disorders, including allergies, ulcerative colitis, rheumatoid arthritis, and other inflammatory joint conditions. Due to its effects on hormones, researchers also consider LSD a potential treatment for immune system disorders, but evidence is currently lacking to support this hypothesis.

In recent years, there has been a significant resurgence in LSD research, driven by growing interest in its potential therapeutic applications. Modern studies are exploring its effects on mental health conditions such as depression, anxiety, PTSD, and addiction. Unlike earlier research, contemporary investigations benefit from rigorous scientific protocols, advanced imaging technology, and a deeper understanding of neuroscience. Pharmaceutical companies and universities worldwide are conducting clinical trials to assess LSD’s safety and efficacy in controlled therapeutic settings. What fuels this renaissance, in part, is a broader societal shift toward reexamining psychedelics as tools for healing rather than mere recreational substances. While the regulatory landscape remains complex, promising early results suggest that LSD, when used under supervision in controlled medical environments, could offer transformative benefits for individuals struggling with a range of mental health challenges.

LSD-Assisted Psychotherapy and Addiction Treatment

In 2014, researchers studied LSD for anxiety associated with life-threatening diseases. In this study, they have found:

“LSD-assisted psychotherapy in patients with life-threatening diseases demonstrated safety and positive stable treatment outcomes at LTFU. Systematic evaluations of semi-structured qualitative interviews with the participants point to cognitive, psychodynamic, and emotional experiences induced by LSD, which contribute to sustained treatment effects. In particular, the emotional ‘peak experiences’ were deeply moving and established another inner frame for addressing and/or coping with the stressful situation.”

A study conducted in 1970 investigated LSD in a hospital setting for the treatment of alcoholism. They noted:

“There is something magical about expecting a single experience, insightful, dramatic, and inspiring as it may be, to drastically change an individual’s habitual lifestyle. Such conversion experiences do, on occasion, lead to radical and enduring modifications in personality functioning, but they are relatively rare. Most alcoholics report a warning of the initial inspiration, euphoria, and good intentions gleaned from the LSD experience when they are again confronted with the former stresses and difficulties in their lives. Greater success could probably be achieved if these individuals received support and additional help extending beyond the hospitalization period to integrate and apply their insights to daily life problems.”

A recent study also used LSD for the treatment of alcoholism, and they reported:

“In a pooled analysis of six randomized controlled clinical trials, a single dose of LSD had a significant beneficial effect on alcohol misuse at the first reported follow-up assessment, which ranged from 1 to 12 months after discharge from each treatment program.”

Subjective Effects and Future Research

Researchers were also interested in the subjective effects of the drug. In a study with 16 healthy subjects, they observed:

“LSD produced pronounced alterations in waking consciousness that lasted 12h. [It] predominantly induced visual hallucinations and audio-visual synesthesia and positively experienced derealization and depersonalization phenomena. LSD also increased subjective well-being, happiness, closeness to others, openness, and trust.”

In this video, Prof. Matthias Liechti talks about the research on LSD in healthy subjects and patients:

Despite the interest in research since the early 1950s, LSD continues to be a stigmatized substance. There is substantial data to support further study of LSD for applications in psychotherapy. More research is needed in patient populations to determine if LSD is efficacious for mental health conditions in therapeutic settings. While trials are ongoing, we need more research on LSD for a deeper understanding of its effects and psychotherapeutic applications.

Therapeutic Timeline of LSD

• 1950 – 1960 – Studies investigating the pharmacology and cognitive effects of LSD started in the early 1950s. Scientists conducted the first LSD-assisted psychotherapy session in 1955.
• 1960 – 1970 – Researchers investigate psychological effects. The use of LSD in psychedelic and psycholytic therapy gained attention. People use LSD for recreational and non-medical purposes.
• 1968 – The US bans LSD, and many other countries follow.
• 1970 – 1980 – Research into the therapeutic potential of LSD halts for decades.
• 1988 – The Swiss government selected a group of researchers to conduct a study on MDMA and LSD. The research continued until 1993 when it was banned again.
• 1990s – Peter Gasser researched LSD-assisted psychotherapy for people suffering from anxiety. Dr Marianne Bloch, Dr Jurai Styk, and Dr Samuel Widmer worked for five years with psychedelic-assisted therapy.
• 2000s – Renewed interest in the therapeutic potential of LSD has led to the approval of several human research studies.
• 2007 – The Beckley Foundation supported the first modern studies using LSD with human participants.
• 2016 – The first neuroimaging study of LSD in healthy individuals was published.
• 2017 to present – Several studies investigate LSD-assisted psychotherapy for anxiety associated with a life-threatening illness.
• 2023 – Two phase 2 trials were completed by MindMed investigating LSD-assisted therapy for anxiety disorders.
• 2024 – The FDA grants a breakthrough therapy designation for MindMed’s formulation of LSD for the treatment of generalized anxiety disorder.
• Ongoing – Current trials investigate LSD for major depression, anxiety, creativity, microdosing, and more. If you are curious about the current clinical trials, visit clinicaltrials.gov for an up-to-date list of LSD studies.

“The FDA’s decision to designate MM120 as a breakthrough therapy for GAD and the durability data from our Phase 2b study provides further validation of the important potential role this treatment can play in addressing the huge unmet need among individuals living with GAD.”

— Robert Barrow, CEO of MindMed.

LSD Microdosing

LSD microdosing involves taking sub-perceptual doses of the substance, typically around 5-10 micrograms, to achieve potential benefits without inducing the psychedelic effects associated with larger doses. Anecdotal reports and a small number of research studies on microdosing suggest it can enhance creativity, focus, and emotional well-being while reducing symptoms of anxiety and depression. Though self-reports have popularized the practice of microdosing, scientific research into its efficacy and safety is still in its early stages. Preliminary studies suggest that microdosing may positively impact mood and cognition, but some findings point to placebo effects as a contributing factor. As interest grows, controlled clinical trials are underway to explore the physiological and psychological effects of LSD microdosing.

LSD Journal Publications

Here is a list of publications from LSD clinical trials, safety studies, microdosing, and neuroscience research.

• Therapeutic Use of LSD in Psychiatry: A Systematic Review of Randomized-Controlled Clinical Trials

• Modern Clinical Research on LSD

• Acute Effects of Lysergic Acid Diethylamide in Healthy Subjects

• LSD-assisted psychotherapy for anxiety associated with a life-threatening disease: a qualitative study of acute and sustained subjective effects

• Safety and efficacy of lysergic acid diethylamide-assisted psychotherapy for anxiety associated with life-threatening diseases

• Lysergic Acid Diethylamide–Assisted Therapy in Patients With Anxiety With and Without a Life-Threatening Illness: A Randomized, Double-Blind, Placebo-Controlled Phase II Study

• LSD-assisted psychotherapy in patients with terminal cancer

• Lysergic Acid Diethylamide (LSD) for the Treatment of Anxiety Disorders: Preclinical and Clinical Evidence

• Repeated low doses of LSD in healthy adults: A placebo-controlled, dose-response study

• Safety, tolerability, pharmacokinetics, and pharmacodynamics of low dose lysergic acid diethylamide (LSD) in healthy older volunteers

• Mood and cognition after administration of low LSD doses in healthy volunteers: A placebo-controlled dose-effect finding study

• Self-blinding citizen science to explore psychedelic microdosing

• LSD and creativity: Increased novelty, symbolic thinking, decreased utility, and convergent thinking

• Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research

• An open-label pilot trial assessing tolerability and feasibility of LSD microdosing in patients with major depressive disorder

• The paradoxical psychological effects of lysergic acid diethylamide (LSD)

• Changes in global and thalamic brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor

• Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution

• The Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future

• LSD alters dynamic integration and segregation in the human brain

• Low doses of lsd acutely increase BDNF blood plasma levels in healthy volunteers

• LSD enhances the emotional response to music

Best Books on LSD

• LSD My Problem Child by Dr. Albert Hoffman

• Mystic Chemist: The Life of Albert Hofmann and His Discovery of LSD by Dieter Hagenbach and Lucius Werthmüller

• Psychedelic Medicine: The Healing Powers of LSD, MDMA, Psilocybin, and Ayahuasca by Dr. Richard Louis Miller

• The Electric Kool-Aid Acid Test Paperback by Tom Wolfe

• Acid Dreams: The Complete Social History of LSD: The CIA, the Sixties, and Beyond by Martin A. Lee, Bruce Shlain

• LSD: Doorway to the Numinous: The Groundbreaking Psychedelic Research into Realms of the Human Unconscious by Stanislav Grof

• Acid Test: LSD, Ecstasy, and the Power to Heal by Tom Shroder

• LSD and the Mind of the Universe: Diamonds from Heaven by Christopher M. Bache

Legal Status

LSD is classified as a controlled substance in most countries, making its manufacture, possession, and use illegal. This classification stems from international agreements like the United Nations Convention on Psychotropic Substances of 1971, which mandates signatory countries to prohibit LSD.

• United States: LSD is a Schedule I controlled substance under the Controlled Substances Act, indicating a high potential for abuse and no accepted medical use. However, some states and local jurisdictions have initiated reforms:
  
  • Oregon: In February 2021, Oregon decriminalized personal possession of small amounts of drugs—including LSD. However, in 2024, the state rolled back this measure due to the increasing opioid and stimulant drug issues.
    
• Canada: Listed under Schedule III of the Controlled Drugs and Substances Act. Unauthorized possession and trafficking can lead to significant legal penalties.
  
• United Kingdom: Classified as a Class A drug under the Misuse of Drugs Act 1971, with severe penalties for unauthorized possession and distribution.
  
• Australia: Classified as a Schedule 9 prohibited substance under the Poisons Standard, restricting its use to approved medical or scientific research.
  
• Mexico: In 2009, Mexico decriminalized the possession of small amounts of drugs, including LSD, for personal use. The law defines specific possession limits.
  
• Czech Republic: Criminalizes possession of amounts greater than small, while possession of smaller amounts is considered a misdemeanor. Judicial practice and regulations determine the exact thresholds.
  
• Switzerland: Switzerland allows restricted compassionate use of LSD and some other psychedelics in a medical context.

It’s important to note that while some countries have decriminalized possession of small amounts for personal use, this doesn’t equate to full legalization. Decriminalization typically means reduced law enforcement—not the absence of legal restrictions.

Given LSD’s complex and evolving legal landscape, it’s crucial to consult local laws and regulations to understand the specific legal status in any given country or region.

Psychedelic Therapy Training Opportunities

Do you want to learn more about LSD? Check out our FREE Little Book of Psychedelic Substances, which includes a guide on the eight most popular psychedelic substances, including LSD. You can learn more about psychedelic research, harm reduction, and therapies in our free psychedelic courses. If you are a health professional looking to earn continuing education credits (CE/CME) and learn more about preparation, integration, and therapeutic approaches, browse our on-demand courses, workshops, and year-long training programs on our Education Page.

This LSD substance guide was initially published on January 22, 2025, and is updated regularly to reflect the latest information on LSD research, therapy, and treatments.