Understanding the Street Name: Which Drug is Lucy?

October 6, 2025 •

2 min read

With a potency so high that noticeable effects can occur with doses as low as 20 micrograms, LSD is one of the most powerful hallucinogens known. Colloquially, it is known by many street names, including 'Lucy,' often referencing the Beatles' song, "Lucy in the Sky with Diamonds". This guide addresses the question: which drug is Lucy? and provides essential information on LSD.

Quick Summary

The street name 'Lucy' is slang for lysergic acid diethylamide (LSD), a potent and unpredictable hallucinogen. The drug alters mood, perception, and thought processes by binding to serotonin receptors in the brain. It is associated with visual distortions and profound sensory experiences known as 'trips.'

Key Points

LSD is 'Lucy': The drug referred to as 'Lucy' is lysergic acid diethylamide (LSD), a potent hallucinogen.
Affects Serotonin: LSD primarily exerts its effects by activating serotonin receptors, particularly the 5-HT2A subtype, causing profound alterations in perception, mood, and thought.
Unpredictable 'Trips': The effects of LSD, often called a 'trip,' are unpredictable and can vary greatly depending on dosage, setting, and the user's mindset.
Psychological Risks: While not physically addictive, LSD use carries risks of psychological distress, 'bad trips,' and potentially long-term conditions like HPPD.
Renewed Therapeutic Interest: Current research is exploring LSD's therapeutic potential for mental health conditions like depression, anxiety, and alcoholism in strictly controlled clinical settings.
Illegal Status: LSD remains a Schedule I controlled substance in the US, indicating a high potential for abuse and no accepted medical use outside of approved research.

What is Lucy? The Drug Behind the Name

When people ask, "which drug is Lucy?" they are referring to Lysergic acid diethylamide, commonly known as LSD. This synthetic substance is odorless and colorless. Its powerful hallucinogenic effects were prominent in the counterculture movement of the 1960s. The experience, or "trip," can be unpredictable.

The Discovery and Rise of LSD

LSD was first synthesized in 1938 by Albert Hofmann, with its psychoactive effects discovered in 1943. Its widespread recreational use in the 1960s led to its federal criminalization in the United States in 1968. The CIA also experimented with LSD.

Pharmacology and Mechanism of Action

LSD primarily works by binding to serotonin receptors in the brain, particularly the 5-HT2A receptor. This affects mood, perception, and cognition by altering neural pathways. This disruption can lead to increased communication between different brain regions and effects like synesthesia.

Common Effects of an LSD 'Trip'

LSD's effects typically start within 30 to 90 minutes and peak 2 to 4 hours after ingestion. A trip can last 8 to 12 hours or more. The experience depends on dosage, mindset, and environment.

Mental and Psychological Effects:

Intense sensory experiences.
Distorted sense of time and space.
Shifts in mood.
Feelings of depersonalization.
Deep self-reflection.

Physical Effects:

Dilated pupils.
Increased heart rate and blood pressure.
Higher body temperature and sweating.
Loss of appetite.
Insomnia, dry mouth, and tremors.

Risks and Potential Adverse Effects

LSD is not considered physically addictive but has psychological risks. A "bad trip" can be terrifying. Long-term effects can include Hallucinogen Persisting Perception Disorder (HPPD) and potentially triggering mental health conditions.

Comparison of LSD vs. Other Psychedelics


Feature	LSD	Psilocybin (Mushrooms)	Mescaline (Peyote)
Potency	Extremely high; effects from micrograms	High; needs milligrams for effects	Lower; requires much higher doses
Duration	8 to 12+ hours	4 to 6 hours	12+ hours; can last longer than LSD
Onset	30–90 minutes	20–60 minutes	1–2 hours; slower onset
Source	Synthetic chemical derived from ergot fungus	Natural fungi, specifically certain mushroom species	Naturally occurring in the peyote cactus
Mechanism	Serotonin (5-HT2A) receptor agonist	Primarily a serotonin (5-HT2A) receptor agonist	Primarily a serotonin (5-HT2A) receptor agonist

Current Therapeutic Research

Despite its illegal status, there is renewed scientific interest in LSD for potential therapeutic uses. Research suggests LSD-assisted psychotherapy may benefit conditions by promoting neuroplasticity.

Key research areas for LSD include:

Depression and Anxiety: Some studies show promise for treating depression and anxiety.
Alcohol Use Disorder: Analysis of older studies suggests a single dose may help reduce alcohol misuse.
Cognitive Flexibility: Research indicates LSD may enhance cognitive flexibility.

This research is conducted in controlled, clinical settings. Recreational use is dangerous. Understanding risks is paramount. For questions about substance use, consult reliable sources like the Alcohol and Drug Foundation.

Alcohol and Drug Foundation: LSD

Frequently Asked Questions

LSD is commonly referred to as 'Lucy' in drug slang, a nickname often associated with the 1967 Beatles song "Lucy in the Sky with Diamonds".

The primary effect of LSD is to cause hallucinations and significantly alter a person's thinking, mood, and perception.

The psychoactive effects of LSD typically last between 8 and 12 hours, though the duration can vary depending on the dosage.

LSD is not considered an addictive drug in the same way as substances like heroin or cocaine, meaning it doesn't cause compulsive drug-seeking behavior.

Yes, some LSD users may experience flashbacks, which are recurrences of aspects of the drug experience that can happen days, weeks, or even years after use.

LSD is classified as a Schedule I controlled substance in the United States, making its possession, manufacture, and distribution illegal under federal law.

While LSD has shown promise in clinical research for treating conditions like anxiety, depression, and alcoholism, it has no currently accepted medical use outside of approved studies.