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Key Points

  • LSD (lysergic acid diethylamide) is a hallucinogenic drug that, when abused, leads to tolerance and a potential behavioral addiction.
  • This drug comes in various forms and is abused orally, often via blotter paper.
  • Short-term side effects range from elevated body temperature and increased heart rate to sleeplessness and confusion. While under the influence, you can start to experience changes to your perception, including altered depth and sense of time.
  • Overdosing on LSD is believed to be rare, as injuries and fatalities are often linked to the combined use of other illicit drugs and substances of abuse. Other cases involve accidents while under the influence — not necessarily due to the drug itself. Despite that, there are safety concerns, especially when you take high doses of LSD or when there is an underlying mental health condition.
  • When considering long-term adverse effects, flashbacks are a key area of research, as are the potential lasting effects for those living with a preexisting mental illness.

What Is LSD?

LSD (lysergic acid diethylamide) is a powerful, semisynthetic hallucinogenic drug that produces strong psychological effects. Other common names include acid, microdots, window pane, mellow yellow, and dots. The DEA states that it has no accepted medical use in treatment within the United States, and abuse can quickly lead to tolerance. While it is not considered to be physically addictive, heavy recreational use can result in a behavioral addiction. [1]

How Is LSD Administered and Abused?

LSD is abused orally, most commonly taken via a saturated absorbent paper, known as blotter paper. This paper is divided into little squares, often with artwork on them. One square is one dose, although the strength of that dose can vary from batch to batch. This drug can also be taken in tablet or liquid form. [1]

What Is the Immediate Effect of LSD on the Body and Mind?

When you first take LSD, you can experience the following short-term effects: [1]
  • Dilated pupils
  • Elevated body temperature
  • Increased heart rate and blood pressure
  • Loss of appetite
  • Nausea
  • Headaches
  • Confusion
  • Euphoria
  • Sweating
  • Dry mouth
  • Sleeplessness
  • Tremors
While under the influence, you can also experience:
  • Impaired depth and time perception
  • Distorted perception of shapes and sizes of objects, sounds, colors, movements, etc.
  • Visual hallucinations that can vary from trip to trip and person to person

Can You Overdose on LSD?

It may be possible to experience an overdose, which would occur after ingesting enough of the drug to cause toxicity or death; it is incredibly rare. LSD is not typically viewed as a life-threatening drug when taken on its own. That said, it’s not safe to ingest large doses, as a “bad trip” could cause symptoms of drug-induced psychosis, anxiety, depression, and depersonalization, which could cause you to do things you wouldn’t normally do. In most cases, when injuries and subsequent deaths occur, LSD is mixed with other substances, or there is a chain reaction of events that leads to an accident, which causes harm, not typically the substance itself. No deaths have been attributed to LSD use alone, but there are always risks involved when taken in an unsafe setting, with other substances, or if one has an underlying mental illness that could lead to dangerous behaviors, including those that involve self-harm. [2]

What About the Long-Term Effects of LSD?

If you or someone you know takes LSD frequently or has been using LSD for extended periods, you may be concerned about any potential long-lasting effects. As a serotonergic hallucinogen, LSD can induce profound alterations of consciousness. For some, there may be some long-term effects. This classic hallucinogen, which is grouped with psilocybin and other psychedelic drugs, produces effects on your brain’s serotonin receptors. [3]

A Closer Look at Flashbacks

Although there are several concerns, especially among those who live with mood and anxiety disorders, one of the most commonly discussed long-term effects is flashbacks. These potential lingering effects are when a user experiences a recurring flashback, often in the form of a visual distortion. There are reports of these lingering effects happening weeks, months, or even years after the drug was last taken. [4] When studied among researchers and health care professionals, this phenomenon, which is often called hallucinogen-persisting perception disorder (HPPD), does occur following the use of LSD and psilocybin. Ongoing psychosis is also a key area of interest among researchers. While recurrent drug effects following the use of LSD were first reported in the 1950s, there is still little consensus on their cause. Incidences of those affected also vary widely, with estimates ranging between 15% and 75% of LSD drug users. However, a more recent review considered data from 142 health subjects across six double-blind studies. It was found that flashbacks are relatively common among healthy subjects after the administration of LSD, affecting up to 9% of users. [5]

Long-Term Effects of LSD and Mental Disorders

When reviewing the potential long-term effects of LSD, you must consider the drug’s potential impact on mental health conditions, including mood disorders, anxiety, schizophrenia, and psychosis. There has been a lot of research presented in recent years, focusing on the potential positive effects of psychedelic drugs. However, many researchers are concerned that these study designs and reporting styles bias positive results over negative effects. [6] Research continues to determine whether drugs like LSD induce psychosis for at-risk groups, such as those with schizophrenia, as they appear to face a higher risk of developing long-lasting psychotic symptoms. [7]

Tolerance and Dependence

Users who frequently take LSD will often rapidly develop a tolerance. After the third or fourth consecutive day, the drug will no longer produce the desired effect. However, tolerance can reset rather quickly following multiple days of abstinence. It’s also possible to develop a cross-tolerance to other psychedelics, including psilocybin. [5]

Are You Struggling With Substance Use Disorder?

Whether you or a loved one is abusing LSD or a combination of other substances, Southeast Addiction Center in Nashville, TN, can help. Learn more about what we treat and the services we offer to take the next step today.

FAQs

What is LSD made from?

LSD is a semisynthetic chemical derived from a substance found in ergot, a fungus that infects rye grain. However, there are reports of drugs being sold as LSD that are actually chemicals, such as NBOMe or the 2C family of drugs. Quality is inconsistent, as is dosing, which can be dangerous. [4]

How long do the effects of LSD last?

When you first take a tab of LSD, effects often begin in 30 to 90 minutes. However, these initial effects are typically strongest between 3-5 hours after taking the drug, and can last up to 12 hours. [8]

What are the most concerning possible long-term effects of LSD?

Flashbacks may become problematic for some users, and there are ongoing concerns about potential dose-dependent effects leading to long-term psychiatric symptoms. If LSD use is part of a more complex substance abuse pattern, this can also be problematic in terms of ongoing addiction and polydrug use, which can quickly cause health problems and become a safety concern.

Sources
[1] LSD. DEA. Retrieved on October 20, 2025: https://www.dea.gov/factsheets/lsd

[2] Can You Really Overdose on LSD? Healthline. Updated on September 2, 2025. Retrieved on October 20, 2025: https://www.healthline.com/health/substance-use/can-you-overdose-on-lsd

[3] Schmid Y, Liechti ME. Long-lasting subjective effects of LSD in normal subjects. Psychopharmacology (Berl). 2018 Feb;235(2):535-545. doi: 10.1007/s00213-017-4733-3

[4] What is LSD? Alcohol and Drug Foundation. Updated on June 6, 2025. Retrieved on  October 20, 2025, from: https://adf.org.au/drug-facts/lsd/

[5] Müller F, Kraus E, Holze F, Becker A, Ley L, Schmid Y, Vizeli P, Liechti ME, Borgwardt S. Flashback phenomena after administration of LSD and psilocybin in controlled studies with healthy participants. Psychopharmacology (Berl). 2022 Jun;239(6):1933-1943. doi: 10.1007/s00213-022-06066-z

[6] Bremler, R., Katati, N., Shergill, P. et al. Case analysis of long-term negative psychological responses to psychedelics. Sci Rep 13, 15998 (2023). https://doi.org/10.1038/s41598-023-41145-x

[7] Sabé, M., Sulstarova, A., Glangetas, A. et al. Reconsidering evidence for psychedelic-induced psychosis: an overview of reviews, a systematic review, and meta-analysis of human studies. Mol Psychiatry 30, 1223–1255 (2025). https://doi.org/10.1038/s41380-024-02800-5

[8] University of Rochester Medical Center. All About LSD. Retrieved on October 20, 2025, from https://www.urmc.rochester.edu/encyclopedia/content?contenttypeid=1&contentid=2604