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How Long Does LSD Stay In Your System?

LSD (Lysergic acid diethylamide) is a psychedelic drug initially synthesized in 1938 by Albert Hofmann from ergotamine, a chemical derivative of ergot (a grain fungus).  In the United States, the drug is considered a Schedule I controlled-substance, meaning it has no accepted medical use and there is a lack of safety associated with its administration.  That said, LSD is among the least addictive drugs, and is currently under investigation as a therapeutic agent for alcoholism, cluster headaches, end-of-life anxiety associated with terminal cancer, and pain management.

A majority of people that use LSD take it recreationally with the intention of having a psychedelic or spiritual experience; hence its classification as an “entheogen.”  The effects or “trip” stemming from LSD’s psychoactive properties are subject to significant individual variation among users.  Certain individuals may report having a powerful spiritual experience, while others may report sheer terror (i.e. “a bad trip”); factors like setting, mindset, and preparation is thought to influence some of the variability in experiences.

In the brain, the drug is thought to alter the neurotransmission of serotonin, dopamine, glutamate, norepinephrine, and epinephrine; it’s psychoactive effects are primarily a result of D2 receptor agonism.  This D2 receptor agonism tends to provoke drug-induced psychosis (leading some to believe that LSD could cause schizophrenia over a long-term).  If you had a bad experience with LSD, you may want to know how long the drug will remain in your system before it is metabolized and cleared.

How long does LSD stay in your system? (Lysergic acid diethylamide)

Assuming you’ve discontinued psychedelics and have worked your way through the nearly non-existent LSD withdrawal symptoms, you should start feeling better within a matter of several days.  The duration of an LSD trip typically falls within the range of 6 to 12 hours, but is subject to individual variation based on numerous factors including: age, body weight, dosage, and tolerance.

Thought there are myths about traces LSD lingering in the spinal cord forever and/or effects of LSD lasting longer than the 6 to 12 hour trip, most evidence suggests that effects subside once the drug has been cleared from the blood.  Early research suggested that the half life of LSD was an estimated 175 minutes (2 hours, 45 minutes), but later research indicated that it could have a half-life of nearly 5.1 hours.

This means that among most users, 50% of the LSD will have been eliminated from the body within just 5 hours of ingestion.  Taking into account both the 2 hour 45 minute and 5.1 hour half-life estimates, this means that for 100% of LSD to clear from your system, it could take between 15.13 and 28.05 hours.  Although LSD is eliminated quickly from a person’s system, it is important to keep in mind that various metabolites may linger for a longer duration.

  • Source: https://www.ncbi.nlm.nih.gov/pubmed/2374410
  • Source: http://www.ncbi.nlm.nih.gov/pubmed/5007719
  • Source: http://www.ncbi.nlm.nih.gov/pubmed/14209776
  • Source: http://www.nhtsa.gov/People/injury/research/job185drugs/lysergic.htm
  • Source: http://www.ncbi.nlm.nih.gov/pubmed/19040555

Factors that may influence how long LSD stays in your system

There are a variety of factors that could have a slight influence over how long LSD stays in your system.  For most people, the effects of LSD will span from 6 to 12 hours, and the drug will be cleared from the body within 24 hours.  However, some people are able to metabolize and excrete LSD (and its metabolites) at a quicker rate than others.  Factors that influence rates of clearance include: age, genetics, other drugs, and dosage of LSD ingested.

  1. Individual Factors

There is usually some variation among LSD users in regards to elimination time.  If two people are given the same dosage of the drug, how can one person metabolize and excrete LSD faster than the other?  Individual factors to consider include: age, body mass index, food intake, genetics, overall health (specifically liver function), and metabolism.

  • Age: Younger individuals that ingest LSD usually absorb and metabolize the drug more efficiently than the elderly (ages 65+). In part this is due to the fact that elderly individuals tend to have less blood flow to their liver, slower metabolisms, and their bodies are no longer operating with peak efficiency.  On the other hand, younger people are usually in good health, fast metabolisms, and optimal liver function.
  • Height / Weight: A person’s height and weight has a significant impact on absorption, metabolism, and excretion of LSD. If administered the same dose of LSD, individuals who are taller and heavier may process it quicker than individuals who are shorter and lighter.  This is usually based upon the fact that the bigger the person, the more of an exogenous substance they can handle (compared to smaller individuals).  Other attributes that could influence the length over which LSD stays in your system include: body fat percentage and amount of lean muscle.
  • Food intake: It is known that if taken with food, LSD may be subject to poorer absorption than if taken on an empty stomach. The size of a meal ingested along with LSD will influence how efficiently a person absorbs the drug.  The more food a person ingests prior to taking LSD, the worse the absorption.  On the other hand, if a person takes LSD on an empty stomach, they’re more likely to absorb more of the drug.  Differences in absorption as a result of food intake can have an impact on metabolism and clearance.
  • Genetics: It is well-documented that genetics can influence drug metabolism and enzymatic function of CYP450 (cytochrome P450). Some people are known to be “fast metabolizers” of drugs whereas others are “slow metabolizers.”  Genetics could influence how rapidly an individual metabolizes LSD, and ultimately influence the rate by which it is cleared from a person’s system.
  • Liver function: Suboptimal liver function is associated with poor clearance of various drugs. A person with impaired liver function may struggle to metabolize and excrete even small amounts of LSD – which could result in toxicity.  Those with healthy liver functioning are capable of metabolizing and excreting LSD at an efficient rate.  Therefore, if you have any abnormalities in liver functioning, it is necessary to consider that these could influence the duration LSD stays in your body.
  • Metabolic rate: An individual’s basal metabolic rate (BMR) could also influence the duration over which LSD remains in the body. A person with a slower-than-average metabolic rate may process LSD at a delayed rate compared to someone with a faster-than-average metabolic rate.  While genetics influencing liver function (CYP450) tend to have a big impact on a person’s ability to metabolize LSD, metabolic rate may also be influential.
  • Stomach pH: The pH level of your stomach will have an impact on the absorption of LSD. Your pH is also thought to influence the pace at which your body is capable of excreting drugs (and metabolites).  Individuals with acidic urine (for example) tend to excrete drugs quicker than those with highly alkaline urine (which facilitates reabsorption).
  1. Dosage (40 mcg to 500 mcg)

LSD is commonly administered at dosages between 40 mcg and 500 mcg (micrograms / millionths of a gram).  To put this in perspective, most users are taking an amount of LSD that is approximately 10% the size of a grain of sand.  A majority of infrequent LSD users typically ingest between 20 mcg and 80 mcg, whereas frequent users typically administer between 100 mcg and 200 mcg per “trip.”

It is important to realize that the dosage of LSD that you ingest may influence how quickly your system is able to process and excrete it.  Studies have shown that administration of 100 mcg LSD can be detected using a radioimmunoassay (RIA) test at around 30 hours.  However, if the dose is doubled, it is thought that the detection time can be extended by approximately 5 hours for each doubling.

In other words, if 100 mcg was detected via a radioimmunoassay 30 hours post-ingestion, the drug could be detected for 35 hours if administered at 200 mcg, and 40 hours at 400 mcg.  Knowing that the detection time is extended for LSD when the dosage increases, it is logical to assume that the greater the dose a person ingests, the longer the drug will stay in their system.  Detection time for urinary metabolites is also though to increase with greater dosages; typically spanning between 34 hours and 120 hours.

  1. Ingestion of other drugs / substances

Simultaneous ingestion of other drugs along with LSD can alter its absorption, effects, and how long it stays in your system prior to excretion.  Regardless of whether the drugs a person has ingested with LSD are illicit, pharmaceutical, or over-the-counter – there’s a chance that they could alter metabolism.  Some drugs are known to inhibit the liver’s ability to metabolize drugs, possibly causing LSD to stay in your body longer than it otherwise would.

Other drugs are known to induce metabolism within the liver and may expedite the metabolism and clearance of LSD from your body.  Individuals who deliberately ingest another drug with LSD could alter its absorption and could modify neurotransmission as to trigger conditions such as “serotonin syndrome.”  In theory, a substance like grapefruit juice inhibits CYP450 and may have subtle effects in prolonging metabolism of LSD (as a CYP450 inhibitor), whereas tobacco may have the opposite effect (as a CYP450 inducer).

  1. Frequency of usage

Though LSD isn’t considered addictive, users can quickly build up a tolerance to normative dosages.  Therefore it can be assumed that the more frequently a person ingests LSD, the greater their tolerance.  As a result of increased tolerance, frequent users of LSD also tend to ingest greater dosages and/or mix their LSD experience with other drugs.

A higher dose of LSD takes longer to get cleared from the body compared to a lower dose.  Furthermore, heavy/frequent use of LSD may result in a greater degree of metabolite accumulation within the body.  Frequent users can expect LSD to clear from their system at a slightly prolonged rate compared to infrequent users.

  1. LSD specifics

The specific source of LSD is thought to dictate potency and purity of the product.  Much of the purity is dictated by how the LSD is stored.  If it is contained within a vial, fully sealed, and without cracks – it will have a different purity than if contained within an improperly sealed vial with a slight crack.  It is known that air-tight brown glass seems to be the most effective way to store LSD for a long-term (i.e. decades) to retain full potency.

The storage and sourcing of your LSD can determine whether you’re taking a highly-pure product, or something of lesser purity.  The purity can have an impact on how well the drug is absorbed and metabolized, as well as how quickly it is excreted.  It is also important to consider whether LSD has been used to lace another drug and/or vice versa.

Furthermore, it is necessary to understand whether someone has ingested legitimate LSD or an LSD analogue (a drug similar to LSD).  Various analogues may be cleared from the body more or less quickly depending on their specific pharmacokinetics.

Note: The modality of administration (oral ingestion or injection) may have subtle influences on absorption and clearance times of LSD, but these are not usually considered significant.

LSD: Absorption, Metabolism, Excretion (Details)

Following oral ingestion of LSD, the drug is absorbed through mucous membranes (or skin) and is completely absorbed by the gastrointestinal tract.  Concentrations of the drug within the bloodstream and various organs peak within 10 to 15 minutes after ingestion, followed by a sharp decrease.  It is estimated that up to 80% of the orally ingested LSD is processed and excreted via the liver, biliary tract, and intestinal tract.

When LSD reaches the liver, it is quickly metabolized by cytochrome P450 enzymes (CYP450) into structurally similar, yet inactive metabolites including: O-H-LSD (2-Oxo-3-hydroxy-LSD), LAE (Lysergic acid ethylamide), Nor-LSD (N-demethylated LSD), LEO (Lysergic acid ethyl-2-hydroxyethylamide), 2-Oxo-LSD, 13-hydroxy-LSD, and 14-hydroxy-LSD.  Of all metabolites, the most prominent to be excreted via urine is 2-oxy-3-hydroxy-LSD; this metabolite remains undetectable within the bloodstream.

In humans, it is thought that only 8% of the total oral LSD dose will appear via urinary excretion.  After 2 hours post-ingestion, only 1% to 10% of LSD will have remained unchanged in urine, the rest will consist of inactive, water-soluble metabolites (e.g. 2-oxo-3-hydroxy LSD).  Though LSD is rapidly metabolized and processed, it is thought to remain in the blood, brain, and other organs in varying amounts for up to 8 hours.

After 24 hours post-ingestion, nearly all LSD will have been metabolized by the liver and excreted from the body.  This also holds true for LSD users who prefer to inject the drug as opposed to take it orally.  Injection is associated with rapid absorption and bloodstream clearance, followed by liver metabolism, and elimination.  Like orally ingested LSD, only 1% to 10% of the drug will remain unchanged in urine.

Usually within 24 hours, most of LSD and its various metabolites will have been eliminated from your body.  In rare cases among those ingesting high dosages and/or other substances could the elimination be prolonged.  Even among heavy LSD users, the drug can be expected to be fully eliminated (100%) from your system within 72 hours (3 days).

  • Source: http://jat.oxfordjournals.org/content/24/7/550.full.pdf

Types of LSD Drug Tests

There are various types of tests that could be utilized to detect the presence of LSD.  Standard drug tests will not test for the presence of LSD, and in most cases, neither will extensive drug tests.  In the past, LSD was tested for among those in the military, but it has since been removed from their testing protocol due to the fact that testing for LSD is expensive.  That said, if you want to test yourself to determine whether LSD is out of your system, it is a possibility.

Urine tests: The most common way to determine whether someone has used LSD is to test their urine for LSD and LSD metabolites.  Not only is urine-based testing fairly expensive, but it is not common.  Furthermore, LSD is not similar in chemical structure to other drugs being tested for on standard urine tests – and therefore will not trigger false-positive for another drug.

Since the metabolite 2-oxo-3-hydroxy LSD has a longer half life than LSD, and is only detectable in urine, this is the substance that will be assessed in urine samples.  LSD and 2-oxo-3-hydroxy LSD are detectable in urine as soon as 3 hours after ingestion, and can remain detectable for up to 3 days post-ingestion.  It would be highly unlikely that the 2-oxo-3-hydroxy LSD metabolite would remain in your system for over 3 days post-ingestion; this would require an extremely large (toxic) dosage.

Blood tests: Another way to determine whether someone has ingested LSD is to collect a blood sample.  It is thought that LSD could be detected in a blood sample as soon as 3 hours and up to 12 hours post-ingestion.  A test known as a radioimmunoassay (RIA) can be used to pinpoint the contents of LSD down to a level of 0.5 ng/ml.

Additionally, another test called an enzyme-linked immunosorbent assay (ELISA) could be used for more advanced detection, pinpointing levels down to 1 pg per 25 microliters of blood. In other words, if you wanted to pinpoint whether someone had likely used LSD and how much was likely in their system, an ELISA would provide the most accurate results.

Other ways to determine whether LSD is still in your system include: HPTLC (high-performance thin layer chromatography) and gas chromatography/mass spectrometry (GC/MS).  Detection limits are thought to be set at 0.1 ng/ml and 0.25 ng/ml for its metabolites.

Hair tests: The testing of hair for the presence of LSD and its metabolites is extremely uncommon.  If you are subject to a hair test, follicles are typically extracted from the top of your head between 3 cm and 6 cm.  Assuming the hair is properly extracted and analyzed with gas chromatography/mass spectrometry (GC/MS) or HPLC (high-performance liquid chromatography), the presence of LSD can be detected.

Since most drugs can be detected up to 90 days (3 months) after ingestion on a hair test, it should be thought that LSD has a similar window of detection.  Hair tests are advantageous in that they can determine whether an individual has ingested LSD over a longer-term than urine or blood tests.  That said, the techniques utilized for a hair test are often time consuming, costly, and require advanced medical equipment – rendering them unfeasible outside of scientific research.

  • Source: http://www.ncbi.nlm.nih.gov/pubmed/8872243

Are people still tested for LSD these days?

Despite the fact that it is possible to test people for the presence of LSD, most drug tests do not seek to determine whether an individual had ingested LSD.  Primarily this is due to the fact that LSD tests are expensive (requiring advanced equipment) and based on the finding that there are relatively few LSD users.  As a result, the costs associated with testing for LSD outweigh the benefits.

  • Businesses / Schools: It is thought that certain businesses and/or schools may test current and prospective employees/students for the presence of LSD.  In addition, some schools may require that athletes receive advanced drug testing (such as for LSD).  That said, testing for LSD by businesses and schools is usually uncommon.
  • Military: In the 2000s, the military initially tested for LSD.  However, as of 2008, testing for LSD was thought to be discontinued as of 2011 based on the finding that a negligible number of personnel tested positive after 3 years.  It is thought that the military still may conduct intermittent/random LSD tests, but these tests aren’t usually a part of standard drug screenings.
  • Rehabilitation clinics: Some rehabilitation facilities may test clients for the presence of all illicit drugs, including LSD.  These clinics may mandate an advanced drug testing panel to ensure that their clients have remained sober from all substances during the rehab process.
  • Self-testing: If you want to know (out of curiosity) whether LSD (and its metabolites) are likely cleared from your system, you could test yourself.  These days LSD test kits can be purchased on Amazon to determine how much of the drug (and its metabolites) remain in your system.

Tips to get LSD out of your system quickly

If you are looking to enhance your body’s ability to clear exogenous substances like LSD, you may want to consider some of the tips listed below.  Understand that these tips may be more effective for certain individuals than others.

  1. Stop using: Assuming you want your body fully clear of LSD and its metabolites, you’ll need to stop using the drug for at least 5 days. After 5 days, you can be pretty sure that it has been completely eliminated from your system. Realize that if you continue ingesting LSD (even at low doses), it will take longer for the drug to be fully cleared from your body.
  2. Diet / hydration: Eating food along with LSD may help your body process the drug and excrete it at a quicker rate. In addition, maintaining proper hydration is necessary if you want to ensure the fastest possible metabolism of LSD and elimination of its metabolites. Metabolites of LSD are eliminated via urinary excretion; drinking enough water can help flush it out.
  3. Manipulate pH: It is known that individuals with a highly alkaline pH may retain drugs (and metabolites) for longer than those with a highly acidic pH. If you want to ensure that LSD is being eliminated quickly and isn’t getting reabsorbed into your system, consider taking steps to increase the acidity of your pH.
  4. Drugs / supplements: Taking certain drugs and/or supplements may act as “inducers” within the liver, speeding up the metabolism (and ultimately elimination) of LSD. Obviously you’ll want to make sure that none of these substances have contraindications with LSD prior to ingestion. That said, they could make a subtle difference if you are concerned about speeding up clearance.
  5. Exercise: Getting daily exercise helps improve blood flow throughout the body and improves health. Daily exercise also helps speed up metabolism and the functioning of organs such as your liver – which is responsible for metabolizing LSD. While the thought of going for a jog may not be too appealing after a “trip,” it could help ensure that the drug clears from your system as soon as possible.

How long do you believe LSD stays in your system?

If you’ve taken LSD, how long do you believe it stayed in your system?  To help others get a better idea of your experience, mention the dosage you took, whether you simultaneously ingested other drugs, whether it was taken on an empty stomach, etc.  Furthermore, if you were drug-tested for LSD, discuss the results of the test below.

Understand that a majority of LSD users will have fully excreted the drug and metabolites within a 24 to 48 hour window.  There’s no reason to think that the drug stays in your system for a longer period of time.  Additionally, there’s no significant evidence to support the myth that LSD remains permanently stored within a person’s spine.

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{ 1 comment… add one }
  • AIMEE PIERSON August 8, 2016, 5:35 am

    I have a positive test for LSD and gave never used it… a gc/ms test confirmation was negative. What would contribute to a positive urine test for LSD?

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