Lysergic acid diethylamide (LSD), commonly known as acid, is a hallucinogenic drug that was once used in psychotherapy and to enhance the effects of antipsychotics. It’s since become popular as an illicit recreational drug and one of the most powerful mood-altering substances.[1]
LSD is detectable in urine, blood, and hair tests, but the tests may not be reliable and must be specialized. The time it takes LSD to leave your system depends on many different factors.
What Is Acid?
Acid is a hallucinogenic drug that was developed by Albert Hoffman, a chemist in Switzerland, in 1936.[2] It’s also known as LSD and was used in the 1950s for psychotherapy. In the following decades, people began to abuse LSD for its mood-altering effects. There are several street names for LSD, including blotter, dots, and yellow sunshine.
Though LSD can’t cause a physical addiction, it’s a powerful psychedelic drug that can intensify thoughts, emotions, and sensory perception. People may use LSD for mystical, spiritual, or religious experiences, though visual and auditory hallucinations and adverse psychological reactions like anxiety, paranoia, and delusions are possible.
How Long Does LSD Stay in Your System?
Oral use of LSD is absorbed by the gastrointestinal system and channeled into the bloodstream. Once in the bloodstream, LSD travels to the brain and other organs like the liver. The liver then breaks it down into other chemicals.
There are several challenges to detecting LSD in tissue samples. Typically, people take small amounts of LSD, so the detection methods must be highly sensitive. The drug is also unstable and broken down by the liver quickly, so the time it’s detectable is limited.
Urine
When you take LSD orally, the liver metabolizes it into inactive compounds. Within 24 hours, only about 1% of LSD is excreted unchanged in the urine. Specialized urine tests can detect it, but most routine urine drug tests don’t detect LSD.
Typically, LSD is detectable in urine using liquid-liquid extraction and ultra-high-performance liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS). Based on research, some inactive metabolites of LSD are present in urine at concentrations that are 16 to 43 times higher than LSD.[3] Researchers aren’t sure how these results can improve LSD detection, however.
Blood
Doctors can use liquid-liquid extraction and UHPLC-MS/MS to detect LSD in blood samples. A recent study used 13 blood samples within 24 hours of administering LSD, kept them at below-freezing temperatures, then analyzed them within 12 months. The researchers were able to detect LSD in samples taken up to 16 hours after administration in all participants who received 200 micrograms of LSD.[4] In those who received 100 micrograms of LSD, the researchers could detect the drug in samples taken up to 8 hours after administration.
The amount of LSD detectable in the samples decreased over time in both groups. In the group that had received 100 micrograms of LSD, only 9 out of 24 samples had detectable LSD after 16 hours.[5] However, these detection methods are highly sensitive and specialized.
Hair
Hair samples can be useful for detecting drugs when people have used them a while ago or if blood or urine tests are not an option. Depending on the drug, it’s possible to estimate the time and duration of ingestion by analyzing the hair’s growth rate and the drug’s evidence on the hair shaft.
A study from 2015 took three documented cases of LSD traces in human hair samples. LSD in the samples was between 1 and 17 picograms per milligram.[6] However, the researchers performed these tests on hair treated with LSD rather than from hair samples of people who had actively used LSD.
Hair samples present challenges with LSD because the drug is active at low doses. There’s limited data on LSD in hair samples, and researchers aren’t certain the drug is stable and detectable in them. Negative results from a hair sample don’t mean the person hasn’t taken LSD.
Factors That Affect LSD Detection
Many factors can affect how long LSD is detectable, including overall health, age, and how much of the drug was taken. One of the most important factors is the timing of the sample because LSD leaves the blood after about 24 hours. Current drug tests can’t detect LSD or its byproducts in urine samples after 72 hours.
In addition, drugs that are similar to LSD may interfere with the detection of LSD. Some tests also have high false-positive rates, which means they may detect LSD when it’s not present.
How Long Do LSD Effects Last?
After a dose of 1 to 3 micrograms per kilogram, most people experience some effects of acid.[7] You can expect to feel the effects about 30 to 60 minutes after taking the drug. Depending on the dose, the effects can last 8 to 12 hours or even longer. Common effects include altered awareness of objects, conditions, thoughts, and feelings.
However, after taking the same amount, people can have wildly different experiences with acids. You can have a “good” trip with bright hallucinations and pleasurable euphoria or a “bad” trip, which may include hallucinations that bring on fear, panic, depression, despair, or any combination of negative emotions.
Some people report flashbacks while taking LSD. Taking other drugs at the same time, feeling fatigued or stressed, and other factors can make flashbacks more likely. You may also experience flashbacks if you’ve used LSD in the past.
Other side effects of LSD may include:[8]
- Increased heart rate
- Increased breathing rate
- Increased blood pressure
- High or low body temperature
- Restlessness
- Loss of appetite
- Shaking
- Sweating
LSD Risks
Some people experience prolonged psychiatric reactions, such as psychosis, but it’s rare. LSD and other hallucinogens aren’t highly toxic to organs like other drugs, even at high doses.
The most significant risk of taking LSD is the dangerous behavior that can result from the effects of the drug. Altering your perception can cause you to behave in ways that may compromise your safety or the safety of those around you.
Is LSD Addictive?
LSD isn’t known to cause a physical addiction, but it can build tolerance if you use it frequently.[9] This means you must take larger doses of LSD to recreate the same high that you’ve experienced previously.
Because LSD doesn’t cause physical dependence, physical withdrawal symptoms don’t occur. If you use LSD regularly, you’re unlikely to experience cravings or strong urges to use the drug. However, it’s possible to become psychologically dependent on the drug, which may require addiction treatment to overcome.
Keep in mind that LSD can have psychological effects, so if you’re struggling to stop using LSD or experiencing adverse effects, you may need addiction treatment to get on a healthier path. Addiction treatment for LSD typically doesn’t include detox because there are no withdrawal symptoms, but inpatient or outpatient addiction treatment programs with therapies to address the psychological aspects, including individual therapy, group therapy, support groups, and behavioral therapies like cognitive behavioral therapy, may be recommended.
LSD is a powerful mood-altering chemical and street drug that can have intense psychological effects. Some tests are capable of detecting LSD and its byproducts for days or months, but these are highly specialized tests that aren’t part of routine drug screening.
