February 2005 Page 1 of 3

LSD (lysergic acid diethylamide) is one of

the major drugs making up the hallucinogen class. LSD was discovered in 1938

and is one of the most potent moodchanging chemicals. It is manufactured

from lysergic acid, which is found in

ergot, a fungus that grows on rye and

other grains.

LSD, commonly referred to as “acid,” is

sold on the street in tablets, capsules,

and, occasionally, liquid form. It is odorless, colorless, and has a slightly bitter

taste and is usually taken by mouth. Often

LSD is added to absorbent paper, such as

blotter paper, and divided into small decorated squares, with each square representing one dose.

The Drug Enforcement Administration

reports that the strength of LSD samples

obtained currently from illicit sources

ranges from 20 to 80 micrograms of LSD

per dose. This is considerably less than

the levels reported during the 1960s and

early 1970s, when the dosage ranged

from 100 to 200 micrograms, or higher,

per unit.

Health Hazards ———

The effects of LSD are unpredictable. They

depend on the amount taken; the user’s

personality, mood, and expectations; and

the surroundings in which the drug is

used. Usually, the user feels the first effects

of the drug 30 to 90 minutes after taking

it. The physical effects include dilated

pupils, higher body temperature, increased heart rate and blood pressure,

sweating, loss of appetite, sleeplessness,

dry mouth, and tremors.

Sensations and feelings change much

more dramatically than the physical signs.

The user may feel several different emotions at once or swing rapidly from one

emotion to another. If taken in a large

enough dose, the drug produces delusions

and visual hallucinations. The user’s sense

of time and self changes. Sensations may

seem to “cross over,” giving the user the

feeling of hearing colors and seeing

sounds. These changes can be frightening

and can cause panic.

Users refer to their experience with LSD as

a “trip” and to acute adverse reactions as

a “bad trip.” These experiences are long;

typically they begin to clear after about

12 hours.

Some LSD users experience severe, terrifying thoughts and feelings, fear of losing

control, fear of insanity and death, and

despair while using LSD. Some fatal

LSD
accidents have occurred during states of

LSD intoxication.

Many LSD users experience flashbacks,

recurrence of certain aspects of a person’s

experience, without the user having taken

the drug again. A flashback occurs suddenly, often without warning, and may

occur within a few days or more than a

year after LSD use. Flashbacks usually

occur in people who use hallucinogens

chronically or have an underlying personality problem; however, otherwise healthy

people who use LSD occasionally may

also have flashbacks. Bad trips and flashbacks are only part of the risks of LSD

use. LSD users may manifest relatively

long-lasting psychoses, such as schizophrenia or severe depression. It is difficult

to determine the extent and mechanism of

the LSD involvement in these illnesses.

Most users of LSD voluntarily decrease or

stop its use over time. LSD is not considered an addictive drug since it does not

produce compulsive drug-seeking behavior, as do cocaine, amphetamine, heroin,

alcohol, and nicotine. However, like many

of the addictive drugs, LSD produces tolerance, so 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 Use ———

Monitoring the Future (MTF)

Survey* 

MTF assesses the extent and perceptions

of drug use among 8th, 10th, and 12th

grade students nationwide. Lifetime**

use dropped significantly among 12thgraders from 2003 to 2004, while annual

and 30-day use remained stable. (Also

see the InfoFacts on High School and

Youth Trends.) Disapproval of taking LSD

on a regular basis dropped significantly

among 8th-graders in 2004. However,

12th-graders who disapprove of trying

LSD once or twice rose significantly.

Perceived availability of the drug fell

among 8th-graders for this same period.

National Survey on Drug Use and

Health (NSDUH)***

NSDUH data show decreases in annual

use of LSD from 2002 to 2003. In 2003,

10.3 percent of Americans aged 12 and

older reported using LSD at least once in

their lifetimes, 0.2 percent had used it in

February 2005 Page 2 of 3

LSD Use by Students, 2004:

Monitoring the Future Survey

8thGraders10thGraders12thGraders

Lifetime 1.8% 2.8% 4.6%

Annual 1.1 1.6 2.2

30-day 0.5 0.6 0.7
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the past year, down significantly from

almost 0.4 percent in 2002. The majority

of lifetime users were over 18; however,

0.6 percent of 12- to 17-year-olds used

LSD in the past year. Among 14- and

15-year-olds, 0.7 percent used LSD in

the past year.

* These data are from the 2004 Monitoring the Future survey, funded by the National Institute on Drug Abuse, National

Institutes of Health, DHHS, and conducted by the University of Michigan’s Institute for Social Research. The survey has

tracked 12th-graders’ illicit drug use and related attitudes since 1975; in 1991, 8th- and 10th-graders were added to

the study. The latest data are online at www.drugabuse.gov.

** “Lifetime” refers to use at least once during a respondent’s lifetime. “Annual” refers to an individual’s drug use at

least once during the year preceding their response to the survey. “30-day” refers to an individual’s drug use at least

once during the month preceding their response to the survey.

*** NSDUH (formerly known as the National Household Survey on Drug Abuse) is an annual survey of Americans

age 12 and older conducted by the Substance Abuse and Mental Health Services Administration. Copies of the latest

survey are available at www.samhsa.gov and from the National Clearinghouse for Alcohol and Drug Information at

1-800-729-6686.

National Institutes of Health – U.S. Department of Health and Human Services

This material may be used or reproduced without permission from NIDA. Citation of the source is appreciated.