LSD (Lysergic Acid Diethylamide)

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OFFICIAL NAMES: LSD (lysergic acid diethylamide), LSD25

STREET NAMES: Acid, zen, sugar, tabs, blotter, cid, doses, trips, boomers, lightning flash, hawk, cheer, liquid acid, L, microdot, dot, paper mushrooms, tab, hits, tripper, yellow sunshines, rainbows, smilies, stars, strawberries

DRUG CLASSIFICATIONS: Schedule I, hallucinogen


Lysergic acid diethylamide, or LSD, is the most potent and widely used of the category of drugs known as hallucinogenics. Hallucinogenic drugs, also called psychedelics, distort and confuse the senses, making people see, hear, feel, smell, or taste things that are not really there. The word hallucinate comes from a Latin word meaning "to wander in the mind." LSD falls into the category of hallucinogenic drugs called indole hallucinogens. This means it is derived from ergot, which is a fungus that grows on grains, particularly rye.

With respect to its hallucinogenic properties, LSD affects vision most strongly, although it can distort or enhance all the senses. The drug also produces intense, unstable emotions. It can make people feel deeply connected with others and with the universe, and can even elicit deeply spiritual experiences. In some people, LSD promotes a sense of deep understanding that forever changes their patterns of thinking or outlook (called a mind-expanding or consciousness-expanding experience). On the negative side, LSD can induce panic, anxiety, or paranoia, and can even disconnect people from reality to such an extent that they become a danger to themselves or others.

LSD is quickly absorbed throughout the body and affects the nervous system at many sites. It is the most powerful known hallucinogenic substance. As little as 30 to 50 micrograms (millionths of a gram) is required to produce effects that last six to 12 hours, sometimes longer. The effects usually start about 30 to 90 minutes after taking the drug; a faster response time may occur at higher doses.

LSD has a fascinating social history. It was initially synthesized in 1938 by Swiss chemist Dr. Albert Hofmann during experiments he performed for Sandoz Laboratories with chemicals called ergot derivates. Other drugs produced from these naturally occurring substances were useful for treating migraine headaches and gynecological problems. It was hoped that additional therapeutic uses could be found from similar compounds.

The testing of LSD on animals in the late 1930s did not identify any useful purpose, but when Dr. Hofmann accidentally ingested the drug in 1943 its hallucinogenic properties were revealed. The drug initially attracted the attention of psychiatrists, who hoped that taking the drug would give them a better understanding of their severely ill patients. Doctors also gave LSD to psychiatric patients to help reduce their inhibitions and enhance psychotherapy. The United States Army and the Central Intelligence Agency (CIA) were interested in LSD as a potential truth serum or brainwashing tool. They also investigated its use as a form of "nonviolent warfare," since LSD can be very incapacitating.

Probably the most important role LSD has played historically is in the hippie movement of the 1960s. LSD use was central to the rebellious movement that encouraged love and peace over war. To the hippie generation of the '60s, LSD was believed to help people develop a peaceful outlook and have profound mystical experiences. It was also popular among artists, particularly musicians, as a means of stimulating creativity.

Sandoz believed that LSD had great potential as a therapeutic drug. However, its increasing street use and association with the counterculture of the sixties made it fall out of favor with most legitimate researchers as well as drug enforcement agencies in various countries, particularly the United States and Britain. As a result, the company stopped producing LSD in 1968.

In 1979, Hofmann wrote an essay entitled LSD: My Problem Child. In it, he described how he first synthesized LSD, his early experiments with the drug, related hallucinogenic drugs found in nature, and the events that led Sandoz Laboratories to abandon the drug.

Traditionally, LSD has been most popular among white, middle-class high school and college students. It is used more in America than anywhere else, although it has enjoyed some popularly in Western Europe, particularly Britain. LSD use was highest in the 1960s, and by 1970 an estimated one million to two million Americans had tried the drug. Use of LSD dropped off somewhat in the 1970s and 1980s, but it resurfaced in the 1990s and early twenty-first century, particularly among young adults who attend dance clubs and all-night dance parties called raves.


LSD is a semisynthetic drug. That means that it is made up of a natural substance, called lysergic acid, which is altered artificially in the laboratory. Lysergic acid is present in a group of substances called ergot alkaloids that are found in nature. These include ergot (Claviceps purpurea), a fungus that grows on rye and other grains. It also includes certain types of morning glory flowers, such as the heavenly blue, pearly gates, wedding bells, flying saucers, and the Hawaiian baby woodrose.

Doses of LSD have been found to be contaminated with other hallucinogen drugs, particularly PCP or mescaline.

LSD is also commonly sold as another hallucinogenic drug, since it is relatively inexpensive to produce.


LSD is almost always taken by mouth. The white, odorless, slightly bitter-tasting crystalline powder is usually dissolved into a liquid form and soaked into blotter paper. The paper is then cut into quarter-inch-square-sized individual doses, called tabs, trips, hits, or doses. The paper is usually decorated with specific designs, such as dolphins, strawberries, or mushrooms, which help identify the manufacturer. Such designs also help to conceal how old the LSD is, as the drug tends to turn yellowish with age.

Less commonly, white LSD powder is squeezed into tiny pills (called microdots) or placed in capsules. It can also be formed into clear gelatin squares called window panes. In the 1990s, LSD has turned up at raves in blue-colored gel wraps that look like bubble-wrap packing material and in small breath freshener-type spray bottles. LSD has also been found on or in postage stamps, cookies, drinks, sugar cubes, and commercially produced candies.

More than 200 types of LSD tablets and more than 350 LSD blotting paper designs have been found. A dose of LSD typically costs about $2 to $5 (U.S.).

In rare cases, people soak tobacco leaves in LSD and smoke it, but this is generally considered to produce a poor-quality high. Even more rarely, some people inject the drug directly into their muscles to produce a more intense experience.


LSD has no officially recognized therapeutic value. However, its use as a therapeutic drug has a rich history. Early research with LSD suggested that it produces states similar to those experienced by people experiencing a type of severe psychiatric disturbance called psychosis, in which patients often hear voices that aren't there, lose touch with reality, have disordered thinking, and experience paranoid thoughts. Mental health experts therefore tried taking LSD to see if it could help them understand their patients' problems.

Soon after, it was also discovered that LSD appears to lower people's inhibitions, making it easier for them to remember and talk about repressed thoughts and experiences. Under positive circumstances, it also promotes empathy among those present who are also taking the drug. These discoveries led mental health experts to give LSD to people with milder mental illnesses, such as depression, to see if it could speed up or improve the effects of psychotherapy. LSD was also used experimentally to help people recover from addiction to other drugs, particularly alcohol.

Despite early positive findings, it was concluded that an LSD high is actually quite different from a psychotic state and that the therapeutic effects as well as the safety of LSD are not certain. Of particular concern was the patient's risk of having "bad trips," which could be so severe as to cause lasting trauma, particularly in those with a history of psychiatric illness. The drug also developed a bad reputation in the 1960s as it gained popularity as a street drug of abuse. For these reasons and others, research into the therapeutic use of LSD dropped off in the 1970s.


Hallucinogenic drugs have been used by different cultures, often in religious ceremonies, for thousands of years. Before LSD, however, this use was limited by the fact that hallucinogenic plants only grow in certain climates and certain areas. When LSD became available on the street in the 1960s, hallucinogen usage soared across the United States and, later, in Western Europe.

Age, ethnic, and gender trends

LSD is the most widely used hallucinogenic drug. Traditionally it has been favored by middle-to upper-middle-class white, educated people in high school or college. It is also popular among artists and musicians because it is believed that LSD experiences can enhance the creative process. It is integrated into the lifestyle of people who follow certain rock groups, such as the Grateful Dead. Historically, LSD has also been a common drug of abuse among mental health professionals. In general, LSD has enjoyed far more popularity in the United States than in any other country.

Patterns of LSD use can best be explained through the drug's history. In the 1940s and 1950s, the drug was tested for various therapeutic uses. At this time, LSD became popular among mental health professionals.

In the 1960s, LSD research was undertaken on college campuses to examine the drug's ability to help change undesirable outlook and behavior patterns as well as elicit profound spiritual experiences. Psychologist Timothy Leary, Ph.D., spearheaded this research. At Harvard University, Leary gave the hallucinogen psilocybin, a drug very similar to LSD, and later, actual LSD, to college professors, graduate students, and other intellectuals in controlled, positive environments to study the experience and its later impact on behavior and outlook. Although Leary was fired from Harvard in 1963, he used his position as a scholar to educate other researchers, and interested individuals about what he believed were the important positive effects of LSD. He was instrumental in promoting the use of LSD across college campuses in the United States, although he never advocated taking the drug for purely recreational purposes.

By 1962, LSD was widely available on the streets of America, and the American Medical Association published a public warning in its journal regarding the increasingly widespread use of LSD for recreational purposes. The drug was most popular in New York and California.

In 1965, street use of LSD in the United States surged, and it peaked from 1967 to 1969. By one estimate, 40% or more of students at Stanford University were using hallucinogenic drugs in 1967. LSD use was high on many other American college campuses as well. Leary himself estimated approximately one million Americans had used LSD at least once by 1967.

The popularity of LSD in the 1960s was at least partially spurred by the political situation at the time. Increasing numbers of young people were seeking higher education, and there was heightened interest in social issues and the workings of the mind. As young people became disenchanted with government decisions, such as the American participation in the Vietnam War, the rebellious "turn on, tune in, and drop out" mentality took hold. LSD was an integral part of that development.

LSD has also experienced some popularity in Britain and other European countries, starting a few years after its use began in the United States. However, LSD has never been used as much in Europe as in America.

As LSD's popularity soared, stories started appearing in the media about crazy things people did while on the drug, such as staring into the sun until they went blind, committing suicide, or committing murder. These stories tended to be wildly exaggerated and, in some cases, simply untrue. However, this negative publicity, combined with stiffer and stiffer legal penalties for manufacture or possession of the drug, eventually helped decrease its popularity. LSD use dropped off in the 1970s and 1980s, while other drugs, particularly crack, cocaine, and heroin, became more common. LSD was still used during these decades, however, mainly by white, middle-class high school and college students.

In the early 1990s, there was a resurgence of LSD popularity. Experts disagree somewhat on why the resurgence occurred, but it seems to be at least partially related to emergence of the rave and club culture. Ravers and clubbers enjoy dancing all night under the influence of drugs that give them more energy (e.g., amphetamines or "speed") as well as hallucinogenic drugs, including LSD and ecstasy (MDMA).

In the 1990s and since the early twenty-first century, LSD has rarely been bought "on the street" from strangers. Most often, it is sold at concerts and raves, and people usually buy it through friends and acquaintances. The typical LSD user is a white, middle-class high school or college student who tends to be a risk taker. Men are slightly more likely to take LSD than are women. In the United States, most illegal LSD is produced in Northern California and distributed through San Francisco to the rest of the country.

Scope and severity

The Monitoring the Future Study (MTF) is a survey performed every year since 1975 by the University of Michigan Institute for Social Research on nearly 17,000 American high school students about their drug use. The survey is funded by the National Institute on Drug Abuse (NIDA). According to this survey, recent LSD use has remained below 10% among high school seniors since1975. The lowest use of LSD was in 1986, when 7.2% reported using LSD at least once, and 4.4% reporting use in the last year. By 1997, 13.6% of seniors said they had used LSD at least once, and 8.4% reported using it in the previous year. From 1996 to 2000, LSD use dropped off slightly among high school students.

Another study, the National Household Survey on Drug Abuse (NHSDA), tracks drug, alcohol, and tobacco use in a sample of 13,000 Americans aged 12 and over. According to this survey, 6% of respondents had used LSD in 1988. The number increased to 7.7% in 1996, and most users were in the 18-to-25 age group.

According to a special analysis of NHSDA and MTF data, the United States experienced a hallucinogen use epidemic in the '90s that peaked in 1996 among predominantly white youths aged 14 to 24. Use remained approximately stable until 1999, then dropped off slightly in 2000 and 2001. This renewal of interest in LSD spurred reports on the drug in major newspapers such as the New York Times and Washington Post, as well as on TV news programs.

According to the Drug Abuse Warning Network, LSD-related emergency room admissions have shown an up-and-down pattern since 1993. In 2000, 4,106 LSD-related admissions were reported.

NIDA reports that 13 million to 17 million Americans have used a hallucinogen at least once. In 1999,8.1% of high school seniors had used LSD in the previous year. One study identified LSD as the third most common drug of abuse among college students, after alcohol and marijuana.

In Britain, LSD usage patterns are similar to those in the United States. The drug became popular in Britain in the mid-1960s, use declined in 1970s and 1980s but picked up again in the 1990s with the rave and club scene. A 1998 study in England and Wales revealed that 11% of respondents aged 16 to 29 said they had tried LSD at least once, and 2% said they had tried it in the previous year.

Patterns of LSD use have changed since the 1960s. According to the United States Drug Enforcement Administration (DEA), typical doses of LSD obtained from illegal sources in the 1990s ranged from 20 to 80 micrograms (mcg), which produces a high that can last 12 hours or longer. In the 1960s and 1970s, a typical dose was closer to 100 to 200 mcg. The LSD available today is produced by about 10 laboratories, all located in or near San Francisco. At the doses used today, 1 gram of crystal LSD produces about 20,000 individual doses.

In the 1960s LSD was often used as a mind-opening or consciousness-expanding experience that encouraged deep understanding or empathy between people. In the 1990s and early twenty-first century, the appeal of LSD appears to be the enjoyment of the intense experience, as users claim it makes everyday life more exciting, unpredictable, and interesting. LSD use is closely tied to attending raves, clubs, and concerts and is often combined with ecstasy by ravers in a practice called "candy flipping."

People who take LSD most often schedule the experience for a special occasion, such as a rave or concert. Even those termed "acid heads" by their friends because of their high use of LSD rarely take the drug more than once or twice a week. Use of LSD is limited by the fact that tolerance to the drug develops very quickly. After someone takes three or four doses close together, a few days must pass without taking the drug for it to be effective again. Also, LSD separates the user so much from reality that he or she cannot function normally while taking it. It is virtually impossible to effectively work, attend classes, drive a car, or even have a normal conversation while on LSD. As a result, people generally don't take the drug if they need to be doing something else.

A few people, usually high school-aged individuals, take LSD on a regular basis to the point that it interferes with their everyday lives, dramatically disrupting sleep, eating, and personal hygiene habits. These heavy users usually notice that their lives are affected by heavy LSD use, but they first attribute this feeling to the effects of the drug itself. In other words, they think the LSD is making them believe that their lives are affected, when, in fact, everything is fine. Fortunately, even these users eventually realize the effect LSD is having on their lives and stop taking the drug. The vast majority of people who use LSD in their youth stop of their own accord as they get older.


LSD is very similar in its chemical composition to serotonin, a chemical found in the brain. Serotonin is a neurotransmitter, which means it is responsible for some of the communication that goes on between brain cells. Serotonin is known to be responsible for behavioral, perceptual, and regulatory systems in the brain, including mood, hunger, body temperature, sex drive, muscle control, and sensory perception. It also helps control mood, thinking, and the identification of new experiences.

It is believed that LSD works by stimulating the effects of serotonin in the brain. This would help explain why all of the senses are usually enhanced or distorted (synesthesia) in people taking LSD and why the drug has a profound effect on mood, thinking, and some basic bodily functions such as temperature control and muscle movement.

Early mental effects

LSD produces profound mental effects that increase with higher doses. Starting about 30 to 90 minutes after taking LSD, depending on the dose, a user will start to notice the following mental effects:

  • Distortion and intensification of all the senses, especially vision. The shapes of objects may appear to blend together or melt, and colors may appear brighter or changed. Depth perception might also become distorted, and objects might have halos or leave trails when they move.
  • Distortions in time and space, in which time seems to flow more slowly and the sense of the shape or position of the body is altered.
  • Synesthesia, or the blending or crossing over of senses, so that people might feel they can see sounds or hear colors.
  • A feeling that everything is very real and familiar.
  • A strong sense of connection with other people (empathy) or connectedness to the universe.
  • A sense of heightened understanding.
  • Impaired judgment, which can make everyday tasks like driving a car dangerous.
  • A feeling of being rooted to the spot, even when moving.
  • Intensification of and rapid changes in mood.
  • The turning inward of attention, often with the sense of being a passive observer of oneself.
  • Uncontrolled laughing or a sense of inner tension relieved by laughing or crying.
  • Euphoria, a feeling of well-being or elation.
  • A sense of being out of the body.

Late mental effects

Starting about one to two hours after taking the drug and usually continuing for eight to 12 hours (depending on the dose) LSD produces the following effects:

  • Vivid hallucinations, or the sensing of things that are not there. Hallucinations produced by LSD are usually visual and are often related to what is really there. So, a person on LSD might see the furniture moving around the room or see people appear unrecognizably different.
  • Extreme emotional instability, to the point of feeling intense fear and panic one second, despair another, and pure joy the next. Some people who have taken LSD say they feel like they are experiencing several intense emotions at once.
  • Difficulty communicating, especially with people who are not also on LSD.
  • Difficulty concentrating.
  • Difficulty distinguishing reality from illusion.
  • A heightened sense of clarity combined with a reduced ability to control what is being experienced.

As the effects of LSD start to wear off, a period called "coming down," occurs. Many people experience some anxiety, depression, and/or fatigue during this time. Unlike what occurs after use of many other drugs, including marijuana and alcohol, people tend to remember their LSD experience.

Negative mental effects

Many people find LSD to be a positive experience, one that makes them feel more connected to the people they get high with as well as with the universe as a whole. When an LSD trip goes badly, however, it can be a very distressing experience. In fact, a bad trip can be so traumatic for some people that they never fully recover. Someone experiencing a bad trip on LSD often feels:

  • extreme anxiety or panic
  • fear of losing control, going insane, or dying
  • fear that their sense of self is fragmenting or disintegrating
  • vivid and sudden thoughts and memories of previous traumatic experiences
  • despair
  • perception of rapid aging in oneself or in others
  • desire to commit suicide (which, in a few rare cases, has actually been successfully carried out)
  • extreme confusion
  • paranoia
  • aggression

Factors affecting mental effects

It is impossible to predict who will have a positive experience with LSD and who will have a negative one. The same person might enjoy an LSD experience one day and have a devastatingly bad trip another day. Early studies with LSD revealed, however, that a number of factors play a crucial role in how an LSD trip is experienced. These include:

  • The setting in which the drug is taken. A comfortable, safe setting in which the user is surrounded by supportive, trusted people increases the chances that an LSD trip will be positive.
  • Dose. The higher the dose, the more intense the experience and the greater the risk that it will be too much for the drug taker to handle.
  • Personality of the drug taker. People who can easily relax and let go are more likely to experience LSD positively than are people who are uncomfortable when they lose control of a situation.
  • Mood of drug taker. LSD tends to intensify the mood a person was in before taking the drug.
  • Expectations of drug taker. To a certain degree, the LSD experience will mimic what the drug taker expects it to be.
  • Reason for taking the drug. People who take the drug of their own accord are more likely to have a positive experience than those who take it for self-therapy or because of peer pressure.
  • Mental health of the drug taker. People with a history of mental health problems are more likely to have bad trips, although negative experiences also occur in people with no such history.

Tolerance to LSD builds up very quickly. After three or four doses are taken over a short period of time, the drug stops having an effect. It only takes a few days off the drug for it to start working again, however. Interestingly, tolerance to LSD also leads to tolerance of other hallucinogenic drugs, even ones that are not chemically related to LSD.


LSD has such powerful mental effects that people do not always notice its physical effects. However, the drug is a powerful stimulant and, as such, has a dramatic effect on the body. Physiological effects people experience with LSD, starting very soon after taking the drug, include:

  • dilated pupils
  • changes in body temperature
  • nausea
  • vomiting
  • headache
  • goose bumps
  • hair standing on end
  • profuse sweating
  • increased blood sugar
  • rapid heart rate
  • increased blood pressure
  • loss of appetite
  • inability to sleep
  • dry mouth
  • tremors
  • dizziness
  • numbness
  • weakness
  • seizures (rare, and only with very high doses)

Harmful side effects

Despite frightening rumors that circulated in the 1960s and 1970s, there is no evidence that taking LSD, even regularly and in high doses, causes damage to the brain, genes, or developing fetuses. Massive overdoses of the drug can, in rare cases, lead to coma, respiratory arrest, overheating of the body, and problems with blood clotting.

Pregnant women should not take LSD because it is known to cause contractions of the uterus. This can bring on a miscarriage.

An LSD trip, especially a bad trip, can make people lose touch with reality to the point that they are a danger to themselves and others. People have been known to have fatal accidents while on LSD because they lost touch with their surroundings. Some people have even purposely harmed themselves or committed suicide during LSD-induced despair. A bad trip can also bring on paranoid thoughts and aggressive tendencies that have led people to harm or even murder others. While these extreme reactions to LSD are rare, they do occur.

Long-term health effects

There are two major long-term risks of taking LSD—flash backs and LSD psychosis.

Flashbacks are known as hallucinogen persisting perception disorder, or HPPD. This is a spontaneous re-experiencing of the effects of LSD that occur without taking the drug. Usually, a flashback does not produce the full effects of an LSD trip. The most common experience is visual hallucinations or disturbances, such as seeing motion at the edges of one's field of vision when nothing has actually moved, or seeing halos around objects or trails behind moving objects. They can occur in people who have been heavy users of LSD or in someone who has taken the drug only once, and they may happen weeks, months, or even years after taking LSD. Most people find flashbacks to be unpleasant and often frightening, particularly because they can mimic the symptoms of serious neurological disorders or brain tumors.

It is not known how common flashbacks are. Estimates of the proportion of LSD users who later experience flashbacks range from 15% to 77%. Flashbacks are more likely to occur in people who regularly took LSD for a long time and in those with other mental health problems. They can also be brought on by taking SSRI (selective serotonin reuptake inhibitor) antidepressant drugs, alcohol, marijuana, or phenothiazines, which are drugs used to treat psychosis. Other flashback triggers are movement in a darkened area, fatigue, hunger, and anxiety.

A very small number of people who take LSD never seem to fully recover from the experience, especially if they had a bad trip. LSD psychosis causes an individual to continue experiencing symptoms related to LSD use including dramatic mood swings, hallucinations, visual disturbances, or severe depression and anxiety. This disorder is most likely to occur in people who had an unstable mental state before taking the drug, who took the drug for the wrong reasons (e.g., to try to treat themselves or because of peer pressure), or who took the drug in a stressful setting. However, well-adjusted people who took LSD in a safe setting also have been known to develop LSD psychosis after only one dose.

There is considerable controversy among experts as to what causes LSD psychosis. Various theories are that the LSD itself somehow damages the brain (although there are no physical signs of brain damage in people who have taken LSD); that a bad trip (like any traumatic experience) brings out mental illness in people who were already susceptible; and/or that LSD breaks down the barriers between the conscious and unconscious mind at the same time that it blocks people's normal inhibitions, thus creating a very vulnerable state.

Regardless of the cause of LSD psychosis, people with this condition usually respond to treatments for the mental illnesses their condition resembles. So, if their symptoms resemble psychosis, they generally respond to antipsychotic drugs.


Little research has been conducted on how LSD interacts with other drugs. The most complete research is with antidepressant drugs because these commonly prescribed medications affect the same brain chemical, serotonin, that LSD does. There are three types of anti-depressants, and each interacts differently with LSD:

  1. SSRI antidepressants, which include Prozac (fluoxetine), Zoloft (sertraline), and Paxil (paroxe-tine), usually decrease the effects of LSD when they are taken together. However, taking an SSRI antidepressant can bring on disturbing flashbacks in someone who has taken LSD in the past.
  2. Tricyclic antidepressants, including Tofranil (imipramine) and Anafranil (clomipramine), usually intensify the effects of LSD.
  3. MAOI antidepressants, such as Nardil (phenelzine), usually decrease the effects of LSD.

Interactions with other drugs have been less closely studied, but anecdotal reports suggest that lithium, a drug used to stabilize mood in people with manic depression or bipolar disorder, increases the response to LSD.

Alcohol can make the visual hallucinations associated with LSD decrease, and people taking LSD often feel they can drink more without getting drunk (a sensation that may not reflect reality).

Ecstasy is another hallucinogen and, like LSD, is popular in club settings. These two drugs are often combined at raves and concerts in a practice called "candy flipping." Some people say that the good mood induced by taking ecstasy can decrease the risk of having a bad trip on LSD. On the other hand, both drugs are powerful hallucinogens and taking them together can create a very intense experience indeed. Often, the more intense the experience, the greater the risk of having a bad trip.

Marijuana can cause paranoia in many people. As a result, it is not considered a good mix with LSD because paranoia can bring on a bad trip. According to research conducted by the NIDA, the combination of LSD and marijuana may bring on psychosis in teenagers.


Fortunately, LSD is not a drug typically associated with long-term abuse. It does not cause physical dependence or addiction, and even psychological dependence appears to be short-lived in most people. Among users, the drug is usually saved for special occasions because taking it more than three or four times over a few days can lead to a tolerance that stops the drug from having any effect. Even those who take LSD regularly usually stop on their own after a few months or years. LSD is rarely taken by anyone after their high school or college years. People usually stop taking LSD because of bad trips or because they have simply had enough of the very intense experience.

Treatment for LSD is sometimes required for its negative short-and long-term effects, however. The most common reason for requiring medical attention after taking LSD is for a bad trip. People having a bad LSD trip can usually be talked down by a trusted person, who calmly explains that the drug taker is safe, that the hallucinations are not real, and that the effects are temporary.

In general, medical personnel avoid giving people on LSD any medication because they cannot be sure what the person has taken, and some of the drugs that might be helpful interact dangerously with street drugs. Left in a quiet room with as little stimulation as possible and with a trusted person to watch over them, people having a bad trip usually settle down and experience lessening of negative effects. However, people who are out of control on high doses of LSD may, in rare cases, require a tranquilizer, such as Valium (diazepam) to calm down. In very rare cases, doctors may give such a person an antipsychotic medication, which is the type of drug given to people with psychosis. Some antipsychotics block the effect of LSD on the brain.

Another reason LSD users sometimes require medical attention is because of flashbacks. There is no way to block flashbacks, so the best way to treat them is to help teach the individual how to cope with them. This involves explaining that the flashbacks are not dangerous or a sign of brain damage, and that the effects usually go away on their own quite quickly. Sometimes, people require psychotherapy to help them overcome the fear associated with flashbacks.

A third reason LSD users might require medical attention is when they develop LSD psychosis. As mentioned earlier, regardless of the underlying cause of psychosis, the best treatment appears to be the same as that used for people who have similar mental health problems not related to taking LSD. So, a person with psychosis following an LSD trip generally responds as well to antipsychotic therapy as a person who develops psychosis without taking LSD does.


Fortunately, most people who try LSD reserve the drug's use for special occasions. However, some heavy users take LSD long enough and frequently enough for it to interfere significantly with their lives. This kind of chronic LSD use can completely disconnect a person from everyday reality, leading to poor performance at school and work, as well as poor or chaotic sleeping, eating, and personal hygiene habits. Although LSD has been touted as a drug that improves connectedness and understanding among users, most heavy LSD users actually stop being able to communicate normally with the people in their lives, especially those who have not shared the LSD experience. They essentially withdraw into an illusory world created by regular LSD use.

Heavy LSD users often notice that their lives are falling apart, but they often initially believe that everything is really the same, and that it is the LSD itself that is making them think their lives are in chaos. This is an example of the extent to which heavy LSD use can disconnect a person from reality. Fortunately, heavy users usually do eventually realize the effect LSD is having on their lives and stop taking the drug on their own. It is rare for people beyond college age to keep taking LSD.

Taking LSD can disconnect people from reality so much that they might do crazy things while they are high, including harming themselves or others. Once a person comes down from an LSD trip, he or she must face the consequences of his or her actions while under the drug's influence. Unlike many drugs that affect memory, LSD enables people to remember everything they did while under the drug's influence.

As with all illegal drugs, taking LSD puts people at risk of getting in trouble with the law. A conviction for drug possession or manufacture can have a substantial negative impact on later efforts to get into college or find a job.

Drugs bought illegally off the street are often not what their sellers claim them to be. This is also true for LSD. Whenever people take LSD, they are risking that they might actually be taking another drug (or combination of drugs), such as mescaline or PCP (angel dust) or that they are taking a much higher dose of LSD than expected.


In the United States, there is no legal use for LSD. As a Schedule I drug, it is considered by the U. S. government to have a high abuse potential, no known medical application, and questionable safety.

Legal history

In the United States, manufacture of LSD first became illegal in 1965. Over the next few years, individual states enacted increasingly stiffer penalties for the manufacture and sale of the drug. In 1968, LSD possession was declared a misdemeanor and its sale a felony. It became a Schedule I drug in 1970. Chemicals used to make LSD, including lysergic acid, ergotamine, and ergonovine, are also controlled substances.

In the United Kingdom, LSD was made illegal in 1966, and medical research with the drug was prohibited in 1973 with passage of the Misuse of Drugs Act. This act listed LSD as a Class A drug, meaning it is not legally available for medical use, and it is illegal to possess or supply it.

Federal guidelines, regulations and penalties

The legal penalties for LSD possession in the United States are severe. Possession of 1 to 9 grams (a dollar bill weighs approximately 1 gram) can lead to a mandatory sentence of five to 40 years in jail and a fine up to $2 million. Sentences are even stiffer for possession of higher doses, for repeated offenses, or for providing LSD that leads to serious injury or death. The most severe LSD-related penalty for an individual is life in prison and up to $8 million in fines.

In the United Kingdom, maximum penalties for LSD-related violations range from seven years imprisonment and a fine for possession, to life imprisonment and a fine for supplying the drug.

See also Designer drugs; DMT (dimethyltryptamine); Ecstasy (MDMA); GHB; Mescaline; PCP (phencyclidine); Psilocybin



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National Institute on Drug Abuse (NIDA), National Institutes of Health, 6001 Executive Boulevard, Room 5213, Bethesda, MD, USA, 20892-9561, (301) 443-1124, (888) 644-6432, [email protected], <>.

Alison Farah Palkhivala, B.A.