LSD—sometimes called acid—is a powerful psychedelic compound with possible therapeutic benefits.

LSD was a popular recreational drug during the 1960s, until the U.S. government made it illegal in 1968. Since then, LSD use has declined. Now, however, LSD is attracting attention in the medical world, where researchers are studying it as a way to make mental health treatments more effective.

Here’s a look at how LSD works, as well as its effects, possible benefits, risks, dosage, and more.

What is LSD?

Lysergic acid diethylamide (LSD) is a potent hallucinogen and one of the “classical psychedelics”—compounds that shift your perception of reality and cause an altered sense of self.

In its pure state, LSD is a white, odorless, flavorless crystal or powder.

LSD street names

LSD is also called:

  • Acid
  • Lucy
  • Sheets
  • Dots
  • Tabs
  • Sunshine

The History of LSD

LSD was first discovered by Albert Hofmann, a Swiss chemist.

Hofmann synthesized LSD for the first time in 1938. He was performing experiments on ergot rot, a type of fungus that grows on rye grains, in an attempt to synthesize new pharmaceutical drugs.

Hofmann didn’t immediately test the LSD after synthesizing it. He made note of its chemical structure, then set it aside for five years.

In 1943, Hofmann returned to LSD, resynthesizing it with the intent of exploring its chemical properties in depth. During this second round of synthesis, Hofmann absorbed a few drops of liquid LSD through his fingertips.

In Hofmann’s own words:

“I was affected by a remarkable restlessness, combined with a slight dizziness. At home I lay down and sank into a not unpleasant intoxicated-like condition, characterized by an extremely stimulated imagination. In a dreamlike state, with eyes closed (I found the daylight to be unpleasantly glaring), I perceived an uninterrupted stream of fantastic pictures, extraordinary shapes with intense, kaleidoscopic play of colors.”

Word of Hofmann’s discovery spread across the world, and by the 1950s, LSD was a popular drug. It was also being used in clinical trials, where researchers were trying to discover whether it could benefit people. Popularity and research continued throughout the 1960s.

However, LSD was eventually made illegal by many of the world’s major governments, starting in the early 1970s (the United Nations required all participating nations to prohibit it in 1971). Research into LSD gradually tapered off, although illegal recreational use continued.

In the last couple decades, LSD has seen a shift in use and legal status. It has been either decriminalized or legalized for personal use in several countries, including Mexico, Ecuador, and the Czech Republic, and researchers in Western countries have taken a renewed interest in studying LSD’s benefits.

What to Expect While on LSD

LSD trips vary from person to person. Keep in mind that your personal experience with LSD will depend on your mindset, your surroundings while you’re on LSD, how much you take, and a variety of other factors.

That said, there are some fairly consistent effects of LSD. Here’s a general idea of what you can expect from an LSD trip.

What Does Taking LSD Feel Like?

LSD’s effects are typically called a “trip.” They last about 10 hours and may include:1,2

  • Visual hallucinations
  • Altered perception of sounds, colors, and objects
  • Euphoria
  • Feelings of happiness and connection
  • Distorted sense of time
  • Ego death (a feeling of oneness with the world around you, or loss of your sense of self)
  • Intensified thoughts and emotions
  • Anxiety
  • Dilated pupils
  • Increased heart rate

It’s worth noting that LSD’s effects vary with your mental state. How the experience goes depends on your mindset, surroundings, who you’re with and how they make you feel, and your mood.

If you’re in a bad mood or are feeling anxious, scared, depressed, or otherwise negative, you may have an unpleasant time taking LSD.

Mechanism of action

LSD works by stimulating your brain’s serotonin 2A (5-HT2A) receptors, which influence your perception, consciousness, and sense of self-identity.1 It also binds to dopamine receptors, causing euphoria and making you feel stimulated and alert.3

Coming down from LSD

LSD doesn’t have any notable biological comedown or hangover effect.

However, taking LSD can be emotionally and mentally intense, and because LSD is also physically stimulating, you may feel exhausted after the experience. It’s a good idea to take LSD on a day when you can get a good night’s sleep afterward.

LSD-assisted therapy

LSD trips are intense and potentially life-changing experiences, and researchers are currently studying the therapeutic benefits of giving people LSD, either combined with talk therapy or under the guidance of a therapist.

Possible benefits of LSD therapy include:

  • A sense of meaning. In a 2018 study, people took a single dose of LSD in a safe, comfortable environment. A year later, 70% of participants described taking LSD as one of the 10 most meaningful experiences in their lives. 4
  • Personal insight. In a survey of more than 1250 people who took LSD, 73% said that they derived a sense of purpose or insight from the experience that improved their life long-term, and 77% said that the LSD trip was among the five most meaningful experiences in their lives. 5
  • Addiction. A growing body of research suggests that combining LSD with talk therapy is an effective way to help alcoholics stop drinking. 6
  • End-of-life anxiety. Several studies have also found that LSD-assisted therapy can relieve anxiety in people with terminal illnesses by helping them accept death. 7,8

While LSD therapy is a promising and fast-growing area of research, it’s still fairly new.  Psychologists are still figuring out LSD’s benefits and how to best use it in a therapeutic setting.

How to prepare for an LSD trip

The two most important ways to prepare for LSD are set and setting.

Set refers to your mindset—your thoughts, mood, and expectations heading into an LSD trip. Stress and fear, resistance, or a controlling mentality may lead to an unpleasant experience (colloquially called a “bad trip”).

Conversely, a relaxed, curious mindset and a willingness to go along with any thoughts and feelings that come up will likely lead to a positive LSD experience.

Setting refers to the environment in which you take LSD. Most people recommend taking LSD in a comfortable, welcoming place with some kind of social support, whether it’s a therapist, close friend, partner, or someone else you trust. It’s best to avoid settings that are inhospitable or demand something of you.

You may also want to avoid obligations, as there’s a good chance you won’t be able to fulfill them while under the influence of LSD, which could be stressful. Close out your work email, arrange for childcare, and put aside everything that might demand your attention until your session is over.

It’s best to take LSD with an open mind and an open schedule.

How do people take LSD?

Pure LSD is a white, odorless, flavorless crystal that can be ground into a powder. However, its raw state is incredibly potent and difficult to distribute in accurate doses. It’s more common to find LSD in one of the following forms:

  • Paper
  • Liquid
  • Micro-dot
  • Gelatin


Small squares of paper, each of which has absorbed a single dose of liquid LSD. You put the paper under your tongue until it starts to dissolve, then swallow it. This is the most common form of LSD.


You can find LSD suspended in liquid. In liquid form, you typically put liquid LSD on the tongue with a dropper. Because a dose of LSD is so small (usually one or two drops from a dropper), liquid LSD can be difficult to dispense accurately. Most knowledgeable users will wear gloves when working with liquid LSD. If you spill liquid LSD on yourself, it will absorb through your skin, and you will have given yourself a much higher dose, and a much more intense effect, than you intended.


A microdot is a tiny dot, about half the size of a grain of rice, that contains a full dose of LSD. You put it under your tongue and let it dissolve.


LSD also comes as a liquid suspended in gelatin.It’s usually cut into pre-portioned cubes, with a single cube being one dose. You let the cube dissolve under your tongue.

While the delivery system for LSD varies, the molecule itself does not. That means you’ll get the same effects, regardless of whether you take LSD via paper, liquid, dot, or any other form.

LSD dosage

A standard LSD dose is about 100 micrograms (100 ?g). 1

It’s worth noting that LSD is incredibly potent. Most drugs work in the milligram range, while LSD works in micrograms (?g), which are 1000 times smaller than milligrams. A miniscule amount of LSD—a tiny square of paper or a dot half the size of a grain of rice—can contain a full 100 ?g dose, capable of making you feel LSD’s full psychedelic effects.

LSD’s potency means it’s important to be careful when dosing. A single drop of liquid LSD, for example, may be one full dose, and you’ll have a much more intense experience if you accidentally take two or three drops.

Fortunately, most LSD on the market is sold in paper form, with the doses already pre-portioned. Typically, one square of paper is a single 100 ?g dose, although you’ll want to confirm this with your provider.

There is no known lethal dose of LSD, making overdose unlikely. However, very high doses can intensify LSD’s effects and make them last longer, which can cause psychological distress or trauma.

Microdosing LSD

Some people microdose LSD—taking 10-20 ?g at a time instead of a full 100 ?g dose, then going about their days normally.

A 2020 survey found that people microdose for three main reasons: mental health (40% of people), personal development (31%), and mental focus (18%). 9

Microdosing may improve your mental state, although it could also cause anxiety. One 2021 study found that microdoses of LSD (either 13 ?g or 26 ?g) increased positive mood, elation, anxiety, and blood pressure in healthy adults, compared to a placebo pill.10 The microdoses also caused measurable changes in electrical activity in participants’ brains.

However, in another study, people saw the same mental improvements with both a microdose of LSD and placebo, suggesting that the benefits of microdosing LSD may just be placebo effect. 11

In other words, it’s not yet clear how microdosing LSD works. Research is still in its early stages.

The Timeline of LSD

How long does LSD take to kick in?

You start to feel LSD about 45 minutes after you take it, and its effects peak at between 1-3 hours after ingestion. 1

How long does LSD last?

An LSD trip lasts for around 9-12 hours, making it one of the longer-lasting psychedelics.

Food affects how LSD’s potency and how long it lasts. Eating a large meal before taking LSD could reduce the amount you absorb by up to 50%, compared to taking LSD on an empty stomach. 12

How long does it stay in your system?

Although its effects only last for about 12 hours, LSD takes about 72 hours to leave your system completely. As a result, LSD is detectable in a urine sample for 1-3 days after you take it.

Potential Risks of LSD

Physical Risks

There are no known physical risks to taking LSD and no evidence that it can cause long-term physical damage. From a physical standpoint, it’s a very safe drug with low potential for abuse.13

Psychological Risks

A bad LSD trip can cause you to feel overwhelmed, scared, depressed, or anxious, and you may feel trapped in that headspace and unable to get out. A bad trip can range from unpleasant to traumatic.

With that in mind, you may want to avoid LSD if you are currently anxious, scared, or in an otherwise negative mental space.

LSD Flashbacks

In some cases, people also experience “flashbacks”—a spontaneous feeling of being on LSD, weeks or months after taking it.

A 2022 study found that about 8% of people who took LSD experienced flashbacks.14 They usually lasted under a minute and happened within a week of taking the drug. The flashbacks caused no lasting problems, and the researchers concluded that they weren’t a serious issue when considering LSD therapy.

Is LSD Addictive?

LSD is not known to be addictive and its risk of abuse is low. 15

Drug Interactions

LSD can interact with certain medications. You should avoid it if you’re taking:

  • Monoamine oxidase inhibitors (MAOIs). MAOIs are a class of antidepressants that work on the same serotonin system that LSD affects. MAOIs may make LSD more effective, causing a more intense experience.
  • Selective serotonin reuptake inhibitors (SSRIs). Another class of antidepressants that influence your serotonin system. In some people, but not everyone, SSRIs may reduce LSD’s effects. 16

You may also want to avoid tobacco and alcohol during an LSD trip. They act as mild MAOIs and can intensify LSD’s effects.

LSD may also interact with other medications in a way that doctors don’t yet understand.

How to Source LSD

Is LSD Legal?

LSD is currently illegal in all 50 states in the U.S., which makes safe sourcing difficult.

Clinical Trials for LSD

One legal way to source LSD is to sign up for a clinical trial. LSD research is a growing field and scientists are looking for people to participate in LSD-related studies. You can search for active clinical trials on the U.S. government’s clinical trial website. This is the safest way to take LSD and will happen under the guidance of a licensed medical professional.

LSD Therapy and Healing Sessions

You may want to avoid self-described “guides” or “healers” who offer to administer LSD therapy. In many cases, they’re unqualified and could end up doing more harm than good. We do not encourage you to break the law, but for comparison purposes, you’d likely be better off taking LSD with a trusted friend or loved one in a familiar, comfortable environment, than with a questionable guide.

Sourcing LSD on Your Own

We do not encourage you to break the law or put yourself in harm’s way. If you’re going to buy LSD outside of a clinical setting, do your due diligence to reduce harm. Avoid purchasing from strangers, and keep in mind that purchasing and possessing any illegal drug could get you into legal trouble. Additionally, there’s always a chance that you’re not getting what you think you’re getting.

You can use an LSD test kit to ensure that what you’re getting contains LSD. Test kits are inexpensive, come with instructions, work on all forms of LSD (paper, liquid, gelatin, etc.), and take a few seconds to administer.

LSD Personal Stories

Here are a few people describing their personal experiences with LSD:

“I was affected by a remarkable restlessness, combined with a slight dizziness. At home I lay down and sank into a not unpleasant intoxicated-like condition, characterized by an extremely stimulated imagination. In a dreamlike state, with eyes closed (I found the daylight to be unpleasantly glaring), I perceived an uninterrupted stream of fantastic pictures, extraordinary shapes with intense, kaleidoscopic play of colors. After about two hours this condition faded away.”

Albert Hofmann, the chemist who discovered LSD in 1943, after synthesizing it in a lab and accidentally spilling some on his skin. Here, Hofmann describes how he felt that day.

“LSD was an incredible experience. Not that I’m recommending it for anybody else; but for me it kind of – it hammered home to me that reality was not a fixed thing. That the reality that we saw about us every day was one reality, and a valid one – but that there were others, different perspectives where different things have meaning that were just as valid. That had a profound effect on me.”

Alan Moore, writer

“I remember being nineteen years old, twelve hours into an LSD trip. I was sitting under a tree and I just started to weep, and I saw what my upbringing had done to me. I saw the resentment of my parents and my callowness and my immaturity and my… And I sat there for about an hour and cried this stuff out. And got up a better person. And to this day I’ve never had to go back and revisit those things…it was just like ten years of psychotherapy in an hour. And it was real.”

Terence McKenna, notable ethnobotanist

LSD Frequently Asked Questions

Is LSD addictive?

LSD is not known to be addictive. It isn’t rewarding the way most drugs of addiction are and studies have found that its risk of abuse is low. In fact, emerging research suggests that taking LSD in combination with psychotherapy may actually help people overcome alcohol addiction.

Can I overdose on LSD?

There have been no known cases of people overdosing or dying from LSD. 13  Physiologically, research suggests that LSD is quite safe. However, high doses of LSD may cause intense disconnection from reality and strong hallucinations, which can be psychologically distressing.

Can I mix LSD with alcohol?

It’s generally not a good idea to mix LSD or other psychedelics with alcohol. While the risk of a drug interaction is low, LSD is an intensely mind-altering drug, and pairing it with alcohol makes its effects more unpredictable than they already are.

Can I mix LSD with other drugs?

Some people mix LSD with MDMA (called “candy flipping”), a practice that’s common at music festivals and raves. However, combining the two can cause excessive serotonin to build up in your brain, which can lead to seizures, irregular heartbeat, and other serious medical complications. It’s safer to take LSD alone.

Can I drive while on LSD?

Do not drive or operate other heavy machinery while on LSD. It’s a strong mind-altering drug that alters your visual and auditory perception. It can also distort your sense of physical space and the passing of time, which can be particularly dangerous if you’re behind the wheel of a car.

Final Thoughts

LSD is a powerful psychedelic with potential benefits, as well as potential risks.

If you choose to take LSD, do so with appropriate preparation, and understand that the potential psychological and legal repercussions could be life-altering. Know your dosage, find a good source, and make sure you’re in a positive headspace and a comfortable, welcoming environment, ideally with people you like and trust.




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