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Generic Name: Lysergic acid diethylamide (LSD)
Common or street names: LSD is sold under more than 80 street names including: Acid, Blotter, acid, Doses, Dots, Trips, Mellow Yellow, Window Pane, as well as names that reflect the designs on sheets of blotter paper (for example, "purple dragon").

What is LSD?

LSD (lysergic acid diethylamide), first synthesized in 1938, is an extremely potent hallucinogen. Hallucinations are when you see, hear, feel, taste, or smell something that seems real but is not. It is commonly called Acid.

LSD is synthetically made from lysergic acid, which is found in ergot, a fungus that grows on rye and other grains. It is so potent its doses tend to be in the microgram (mcg) range. It's effects, often called a "trip", can be stimulating, pleasurable, and mind-altering. It some cases it can lead to an unpleasant, sometimes terrifying experience called a "bad trip".

In the U.S., LSD is illegal and is classified by the Drug Enforcement Agency (DEA) as a Schedule 1 drug, meaning LSD has a high potential for abuse, has no currently accepted medical treatments, and has a lack of accepted safety for use under medical supervision. However, despite being a Schedule 1 substance, there has been a resurgence of interest in potential therapeutic uses for LSD, such as for the treatment of alcoholism and depression. Studies that conform to modern research standards are currently underway that might strengthen our knowledge on the use of LSD.

LSD is produced in crystalline form and then mixed with other inactive ingredients, or diluted as a liquid for production in ingestible forms. It is odorless, colorless and has a slightly bitter taste.

Active doses for LSD between 0.5 and 2 mcg/kg (100–150 mcg per dose). Its half-life is about 3 hours, but ranges between 2 hours and 5 hours, and the psychoactive effects can last up to 12 hours.

LSD is usually found on the streets in various forms, for example:

  • blotter paper (LSD soaked onto sheets of absorbent paper with colorful designs; cut into small, individual dosage units) - the most common form
  • thin squares of gelatin (commonly referred to as window panes)
  • tablet form (usually small tablets known as Microdots) or capsules
  • liquid on sugar cubes
  • pure liquid form (may be extremely potent)

Some people may inhale LSD through the nose (snort) or inject it into a vein (shoot it up). There is no way to predict the amount of LSD that is contained in any form consumed.

Other hallucinogens include:

Effects of LSD Use

LSD is a mind-altering drug. It is thought LSD causes its characteristic hallucinogenic effects via interaction with the serotonin receptors in the brain. Serotonin is a neurotransmitter that helps control your behavior and mood, governs your senses, and moderates your thoughts.

The physical effects of LSD are unpredictable from person-to-person. Usually, the first effects of the drug when taken by mouth are felt 30 to 45 minutes after taking it, peak at 2 to 4 hours, and may last 12 hours or longer. Use by the intravenous (IV) route will produce a much quicker action, usually within 10 minutes. Effects include:

  • hallucinations
  • distorted visual perception of shapes, colors
  • altered sounds
  • anxiety and depression
  • flashbacks (a return of the "trip" experience) days or months later
  • rapid heart rate, increased body temperature and high blood pressure
  • dilated pupils

Extreme changes in mood can occur. If taken in large enough doses, the drug produces delusions and visual hallucinations. Overdose can lead to severe psychosis. Death is often due to a direct injury while under LSD influence; there is no known lethal dose of LSD.

The physical effects can also include nausea, loss of appetite, increased blood sugar, difficulty sleeping, dry mouth, tremors and seizures.

The user may also experience impaired depth and time perception, with distorted perception of the size and shape of objects, movements, color, sound, touch and their own body image. Sensations may seem to "cross over," giving the feeling of hearing colors and seeing sounds. These changes can be frightening and can cause panic. Some LSD users also experience severe, terrifying thoughts and feelings, fear of losing control, and fear of insanity or death.

An experience with LSD is referred to as a "trip". Acute, disturbing psychological effects are known as a "bad trip". These experiences are lengthy, with the effects of higher doses lasting for 6 to 12 hours, and it may take 24 hours to return to a normal state.

Health Hazards and Flashbacks with LSD

Under the influence of LSD, the ability to make sensible judgments and see common dangers is impaired, making the user susceptible to personal injury or death.

After an LSD trip, the user may suffer acute anxiety or depression, and may also experience flashbacks (also called hallucinogen persisting perception disorder), which are recurrences of the effects of LSD days or even months after taking the last dose.

  • A flashback occurs suddenly, often without warning, usually in people who use hallucinogens chronically or have an underlying personality problem.
  • Healthy people who only use LSD occasionally may also have flashbacks.
  • Bad trips and flashbacks are only part of the risks of LSD use. LSD users may also manifest relatively long-lasting psychoses, such as schizophrenia or severe depression.

LSD produces tolerance, meaning the user needs greater doses of LSD to get the same high. Some users who take the drug repeatedly must take progressively higher doses to achieve the state of intoxication that they had previously achieved. This is an extremely dangerous practice, given the unpredictability of the drug.

Extent of LSD Use

Rates of LSD and hallucinogens in general use remain low among youth in the U.S.

  • The National Survey on Drug Use and Health (NSDUH) in 2020 estimated that 7.1 million people aged 12 or older were past year users of hallucinogens, corresponding to 2.6% of the population.
  • Hallucinogens include LSD, PCP, peyote, mescaline, psilocybin mushrooms, Ecstasy, ketamine, DMT/AMT/“Foxy,” (DMT is the main active ingredient in Ayahuasca), and Salvia divinorum.

The percentage of use among adults aged 18 to 25 (7.3% or 2.4 million people) was higher than the that among adolescents aged 12 to 17 (1.5% or 370,000 people) or adults aged 26 or older (2% or 4.3 million people).

In 2021, based on data from NIDA's Monitoring the Future 2021 Survey Results: Overall Findings, past year illicit drug use for LSD among surveyed 12th graders was 2.5%, a drop of 1.4% points. As a comparison, this was far below illicit drug use for marijuana, which stood at 30.5% (compared to 35.2% in 2020) for 12th graders.

Past MTF surveys found that "generational forgetting" -- students stating that they are not familiar with the drug -- has resulted in a decline in perceived risk of LSD among younger groups, which may put them at higher risk of use in future years. This points to the need for continued education over time on all illicit drugs (including hallucinogens) that may be a risk for youth.

Treatment for LSD Use

Once a decision is made to obtain treatment, there are several steps to take.

  • Speak to a healthcare provider to help direct you to reliable sources of help and monitor your progress.
  • Talk therapy (behavioral counseling) and group counseling may be an option to help you understand your behaviors and why you continue to use LSD.
  • Keep your appointments and follow your providers treatment plan. Consider including trusted family or friends in your treatment plan.
  • Take good care of yourself: exercise, eat healthfully, and control your stress level. Surround yourself with supportive people.
  • Added medical therapy may be needed to treat symptoms due to drug use, such as anxiety, depression, or schizophrenia.
  • Work to find new hobbies and interests that will take your mind off of drug use. Consider a volunteer opportunity.
  • Each day make an effort to stay away from people who abuse drugs, even if they are former friends.

Medical Research with LSD

LSD remains a Schedule I controlled substance in the US. However, research in the 1950's to 1970's suggested therapeutic potential for LSD, including use in mental health disorders such as for the treatment of anxiety, depression, psychosomatic diseases and addiction. However, many studies contained methodological flaws and only recently has the interest of medical use for LSD resurfaced.

  • In one 2020 systematic review from Spain, researchers evaluated controlled and randomized clinical trials. The authors used the Cochrane Collaboration Tool to assess studies for risk of bias, and 11 studies were selected.
  • LSD was administered to 567 patients in a dose that ranged from 20 micrograms (mcg) to 800 mcg. Doses were primarily given by the oral route, but IV route was used in one study.
  • The authors determined that LSD possesses potential therapeutic uses, with the strongest evidence for use in the treatment of alcoholism.
  • Two serious adverse events were reported: seizures in one participant and psychosis in another. Both people had a past history of these conditions, and they both recovered from these events without complications.

Additional Resources


See also


  1. Fuentes J, Fonseca F, Elices M, et al Therapeutic Use of LSD in Psychiatry: A Systematic Review of Randomized-Controlled Clinical Trials . Frontiers in Psychiatry 2020(10):943
  2. Passie T, Halpern JH, Stichtenoth DO, et al. The pharmacology of lysergic acid diethylamide: a review. CNS Neurosci Ther (2008) 14:295–4.
  3. Substance Abuse and Mental Health Services Administration. Key Substance Use and Mental Health Indicators in the United States: Results from the 2020 National Survey on Drug Use and Health. Accessed Jan. 28, 2020 at
  4. Monitoring the Future 2021 Survey Results: Overall Findings. National Institute on Drug Abuse (NIDA). Accessed July 12, 2022 at
  5. Substance Abuse and Mental Health Services Administration, National Survey on Drug Use and Health: Trends in Prevalence of Various Drugs for Ages 12 or Older, Ages 12 to 17, Ages 18 to 25, and Ages 26 or Older; 2015 - 2016 (in percent). Accessed July 12, 2022 at
  6. LSD. U.S. Drug Enforcement Agency (DEA). Accessed July 12, 2022 at
  7. National Institute on Drug Abuse (NIDA). Research report series: hallucinogens and dissociative drugs. Accessed July 12, 2022 at
  8. NIDA. Why Do People Take Hallucinogenic or Dissociative Drugs? June 1, 2020. Retrieved from on July 12, 2022
  9. Hallucinogens and Dissociative Drugs. From the Director. National Institute on Drug Abuse (NIDA). Accessed July 12, 2022 at
  10. Substance use - LSD. MedLine Plus. U.S. National Library of Medicine. 5/10/2020. Accessed July 12, 2022 at
  11. LSD Overdose. Accessed July 12, 2022 at
  12. Hallucinogens. National Institute on Drug Abuse (NIDA). Accessed July 12, 2022 at 

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.