LSD is a mind-altering drug. This means it acts on your brain (central nervous system) and changes your mood, behavior, and the way you relate to the world around you. LSD affects the action of a brain chemical called serotonin. Serotonin helps control behavior, mood, the senses, and thinking.

LSD is in a class of drugs called hallucinogens. These are substances that cause hallucinations. These are things that you see, hear, or feel while awake that appear to be real, but instead of being real, they have been created by the mind. LSD is a very strong hallucinogen. Only a tiny amount is needed to cause hallucinations.

LSD users call their hallucinogenic experiences "trips." Depending on how much you take and how your brain responds, a trip may be "good" or "bad."

A good trip may be stimulating and pleasurable. A bad trip can be very unpleasant and frightening.

The danger of LSD is that its effects are unpredictable. This means when you use it, you do not know if you will have a good trip or a bad trip. There is no way to know how it will affect you:

• You may feel as if you are floating and disconnected from reality.
• You may feel joy (euphoria, or "rush") and less inhibition, similar to being drunk from alcohol use.
• You may feel as if your thinking is extremely clear and that you have superhuman strength and are not afraid of anything.
• Your senses may become distorted. Shapes and sizes of objects may be altered. Or your senses may "cross over." You may feel or hear colors or see sounds.
• You may have many emotions at once, or move quickly from feeling one emotion to feeling another.
• You may have terrifying thoughts.
• Fears that you normally can control may become out of control. For example, you may have doom and gloom thoughts, such as thoughts that you will soon die, or that you want to harm yourself or others.

How fast you feel the effects of LSD depends on how you use it:

• Taken by mouth: Effects usually start in 20 to 30 minutes. The effects peak in about 2 to 4 hours and last up to 12 hours.
• Shooting up: If given through a vein, LSD's effects start within 10 minutes.

LSD can harm the body in different ways and lead to health problems such as:

• Increased heart rate, blood pressure, breathing rate, and body temperature
• Sleeplessness, loss of appetite, tremors, sweating
• Mental problems, including anxiety, depression, schizophrenia

Some LSD users have flashbacks. This is when parts of the drug experience, or trip, return, even without using the drug again. Flashbacks occur during times of increased stress. Flashbacks tend to occur less often and less intensely after stopping use of LSD. Some users who have frequent flashbacks have a hard time living their daily life.

LSD is not addictive and does not cause compulsive use. But LSD can quickly lead to tolerance even after using it for just a few days. Tolerance means you need more and more LSD to get the same high.

Treatment begins with recognizing there is a problem. Once you decide you want to do something about your LSD use, the next step is getting help and support.

Treatment programs use behavior change techniques through counseling (talk therapy). The goal is to help you understand your behaviors and why you use LSD. Involving family and friends during counseling can help support you and keep you from going back to using (relapsing).

Because LSD use may cause mental problems, medicines may be also prescribed to help treat symptoms of anxiety, depression, or psychosis.

As you recover, focus on the following to help prevent relapse:

• Keep going to your treatment sessions.
• Find new activities and goals to replace ones that involved your LSD use.
• Spend more time with family and friends you lost touch with while you were using LSD. Consider not seeing friends who are still using LSD.
• Exercise and eat healthy foods. Taking care of your body helps it heal from the harmful effects of LSD. You will feel better, too.
• Avoid triggers. These can be people you used LSD with. They can also be places, things, or emotions that can make you want to use it again.

Resources that may help you on your road to recovery include:

• Partnership for Drug-Free Kids -- drugfree.org/
• LifeRing -- www.lifering.org/
• SMART Recovery -- www.smartrecovery.org/

Your workplace employee assistance program (EAP) is also a good resource.

Contact your health care provider if you or someone you know is using LSD and needs help stopping.

Substance abuse - LSD; Drug abuse - LSD; Drug use - LSD; Lysergic acid diethylamide; Hallucinogen - LSD

Kowalchuk A, Reed BC. Substance use disorders. In: Rakel RE, Rakel DP, eds. Textbook of Family Medicine. 9th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 50.

National Institute on Drug Abuse website. Psychedelic and dissociative drugs. nida.nih.gov/research-topics/psychedelic-dissociative-drugs. April 2023. Accessed May 22, 2024.

Weiss RD, Liebschutz JM. Drug use disorders. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 365.

Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.