LSD facts

LSD (lysergic acid diethylamide) is a powerful hallucinogenic drug that’s usually found on blotter paper, in liquid form, or on sugar cubes.

Often called “acid”, LSD is illegal in Ireland and is a Schedule 1 drug under the Misuse of Drugs Acts. People use it for its mind-altering effects, including visual distortions, changes in mood, and altered sense of reality.

Here, we break down everything you need to know about LSD and its effects.

What is LSD?

LSD is a synthetic psychedelic drug made from ergot, a fungus that grows on rye and other grains. It is active in very small doses and is one of the most potent hallucinogens known.

What does LSD stand for?

LSD stands for lysergic acid diethylamide. It was first synthesised in 1938 by Swiss chemist Albert Hofmann.

What are the street names for LSD?

Common street names for LSD – which usually refer to LSD placed on blotter paper – include:

• Acid
• Blotter
• Lucy
• Dots
• Mellow Yellow
• Tabs

How is LSD taken?

LSD is usually taken orally. The most common method is by swallowing blotter paper squares that have been soaked in LSD solution. It can also be found as:

• A clear liquid dropped on food or directly into the mouth
• Sugar cubes soaked in LSD
• Thin gelatine squares (sometimes called “window panes”)
• Pills or capsules

What does LSD look like?

Pure LSD is a colourless, odourless liquid. Because it is used in such small amounts, it’s usually absorbed onto a carrier such as blotter paper decorated with colourful designs. LSD can also be found in pill or capsule form, gelatine squares, or as liquid drops.

What is LSD blotter paper?

Blotter paper is the most common way LSD is sold. Sheets of absorbent paper are soaked with LSD solution and then cut into small squares known as “tabs”. Each square usually contains one dose.

How long do the effects of LSD last?

The effects of LSD usually begin within 30-60 minutes of taking it.

A “trip” can last between 7 and 12 hours, depending on the dose, the user’s metabolism, and other factors.

How long does LSD stay in your system?

LSD itself leaves the bloodstream within a few hours, but its metabolites (breakdown products) can be detected for much longer.

Detection times for LSD drug testing vary depending on the test type:

• Hair – up to 12 months (depending on the length of hair available)
• Nails – up to 12 months (up to 6 months for fingernails and up to 12 months for toenails)

Learn more: How long does LSD stay in your system?

What are the short-term effects of LSD?

LSD alters perception, mood and thought. While the effects can vary from person to person, some common short-term effects include:

• Visual distortions (patterns, colours, shapes)
• Altered sense of time
• Intense emotions (euphoria, anxiety, confusion)
• Synaesthesia (mixing of senses, e.g. “hearing colours”)
• Increased energy or restlessness

Learn more: The effects of substance misuse

What are the psychological effects of LSD?

The psychological effects of LSD can include:

• Heightened creativity and introspection
• Spiritual or mystical experiences
• Anxiety, paranoia, or panic (especially during a “bad trip”)
• Disorganised thoughts or difficulty concentrating

In some cases, LSD can trigger persistent effects such as flashbacks or hallucinogen persisting perception disorder (HPPD).

What are the physical effects of LSD?

Although LSD mainly affects the brain, it can also cause physical side effects, including:

• Dilated pupils
• Increased heart rate and blood pressure
• Sweating or chills
• Tremors and muscle weakness
• Nausea or dizziness

What does an LSD trip feel like?

According to people who have used LSD, an LSD trip can feel dreamlike and surreal. Users may see bright colours, shifting shapes or patterns on surfaces.

Some people also report feeling euphoric and connected to their surroundings, while others may feel anxious or overwhelmed.

What is a “bad trip”?

A “bad trip” is a distressing LSD experience that can last many hours and can sometimes have lingering psychological effects.

It may include:

• Intense fear or panic
• Disturbing hallucinations
• Paranoia or a sense of losing control
• Feelings of doom or despair

What are flashbacks and HPPD?

Flashbacks are spontaneous recurrences of parts of an LSD trip, often weeks or months later.

Some people also develop hallucinogen persisting perception disorder (HPPD), where visual disturbances continue long after LSD use. HPPD is rare but can be distressing.

What does LSD do to the brain?

LSD acts mainly on serotonin receptors in the brain, especially 5-HT2A receptors. This disrupts normal brain network activity, leading to altered perception, mood, and thought processes.

Is LSD addictive?

LSD is not considered physically addictive and does not cause cravings or withdrawal symptoms.

However, people can develop a tolerance if they use it repeatedly, meaning larger doses are needed to feel the same effects.

Can you overdose on LSD?

While a fatal overdose on pure LSD is extremely rare, taking very high doses of LSD can cause dangerous psychological effects, including:

• Severe anxiety or paranoia
• Psychosis-like episodes
• Dangerous behaviour or accidents while under the influence

The bigger risk while taking LSD comes from substances that are mis-sold as LSD. This includes NBOMe compounds which are sometimes sold as LSD and can be toxic.

What are NBOMe compounds?

NBOMe (pronounced “N-bomb”) refers to a family of synthetic hallucinogens, such as 25I-NBOMe, 25C-NBOMe, and 25B-NBOMe. These drugs are chemically unrelated to LSD but can be placed on blotter paper and sold as “acid”.

NBOMes are much more dangerous than LSD:

• Active at microgram doses, making them easy to overdose on by accident
• Associated with seizures, heart problems, and organ failure
• Documented cases of hospitalisations and deaths worldwide

Unlike LSD, NBOMe compounds do carry a significant risk of fatal overdose.

What happens if you take too much LSD?

High doses of LSD can cause:

• Intense hallucinations
• Severe confusion
• Agitation or aggression
• Psychosis-like symptoms
• Risk of accidental injury

Is LSD dangerous?

The main danger from LSD is that its side effects can be unpredictable, varying widely from person to person.

Risks of taking LSD include:

• Psychological distress or trauma from bad trips
• Accidents or injuries while hallucinating
• Triggering underlying mental health conditions
• Legal consequences (Schedule 1 drug)

Can LSD be mixed with other drugs?

Mixing substances – also known as poly drug use – always comes with risks.

For example:

• Drinking alcohol while taking LSD can increase nausea and confusion.
• Taking stimulants (e.g. cocaine or MDMA) with LSD can raise heart rate and blood pressure.
• Mixing antidepressants (especially SSRIs or lithium) with LSD can cause unpredictable and sometimes dangerous interactions.

How does LSD work in the brain?

LSD mainly affects the serotonin system in the brain, especially the 5-HT2A receptor.

By binding to these receptors, LSD disrupts normal communication between brain regions. This leads to changes in perception, mood, and thought.

Brain imaging studies show LSD reduces activity in the “default mode network” – the part of the brain linked with self-awareness – which may explain feelings of ego loss or altered consciousness during a “trip”.

How long does it take for LSD to kick in?

When taken orally, LSD typically begins to take effect within 30 to 60 minutes.

Some people feel subtle changes earlier, while others may not notice anything for over an hour. The peak effects generally occur 2 to 4 hours after taking a dose.

What is the legal status of LSD in Ireland?

LSD is a Schedule 1 controlled drug under the Misuse of Drugs Acts 1977–2016. This means it has no recognised medical use and is strictly illegal in Ireland.

• Possession of LSD can result in a fine, up to 12 months in prison on summary conviction, or both. More severe penalties may apply if the case goes to a higher court.
• Supplying, producing, or trafficking LSD is treated as a very serious offence. Conviction on indictment can lead to life imprisonment, an unlimited fine, or both, depending on the scale of the offence.

You can read the legislation in full on the Irish Statute Book.

Has LSD ever been used in medicine?

Yes. In the 1950s and 1960s, LSD was studied as a potential treatment for mental health conditions, including depression, anxiety, and alcohol dependence.

Research was halted after LSD was made illegal, but interest has recently returned. New clinical studies are investigating whether LSD and similar psychedelics could help treat mental health disorders under controlled medical conditions.

Is it true that LSD stays in your spine forever?

No. This is a myth. LSD does not stay in the spinal fluid or the spine. Reports of LSD “hiding in the spine” are urban legends with no scientific basis.

Can LSD cause genetic damage or mutations?

There is no evidence that LSD causes genetic damage or mutations. Early studies in the 1960s suggested possible links, but later research showed these results were flawed.

Today, scientists agree that LSD does not cause chromosome damage or birth defects.

Which drugs are similar to LSD?

Several substances produce psychedelic effects similar to LSD, including:

• Psilocybin (found in magic mushrooms)
• Mescaline (from peyote and San Pedro cacti)
• DMT (dimethyltryptamine, found in ayahuasca)
• Other synthetic lysergamides, such as AL-LAD and 1P-LSD

All these drugs alter perception, mood, and thought, but differ in duration, intensity, and use.

Is PCP similar to LSD?

No. Although phencyclidine (PCP) is sometimes mistaken for LSD, they are very different drugs.

• LSD is a hallucinogen that mainly affects serotonin receptors and alters perception.
• PCP is a dissociative anaesthetic that works on NMDA receptors, causing detachment, confusion, and sometimes aggression.

PCP is not chemically or pharmacologically related to LSD and has a much higher risk profile.

What should you do if someone is having a bad trip?

If someone is experiencing a bad trip, it’s important to:

• Stay calm and reassure them that the effects will pass.
• Keep them safe by removing anything they could use to harm themselves.
• Move them to a quiet, comfortable space away from crowds or loud noises.
• Avoid confrontation and speak gently.
• Seek medical help if they are extremely distressed, aggressive, or showing signs of physical danger (e.g. seizures, high temperature).

Where can I buy a drug test?

At AlphaBiolabs, we offer a variety of drug tests to detect a wide range of substances, including LSD and other hallucinogens.

Our ISO 17025-accredited laboratory provides drug testing for peace of mind, the legal profession, and businesses.

For guidance on the most suitable drug test for your circumstances, call us on 01 402 9466 or email info@alphabiolabs.ie, and our team will be happy to assist you.