According to the National Institute on Drug Abuse, around one out of every ten people in the U.S. have taken LSD at least once during their lifetime.

When using LSD, people often report visual effects and altered sensory experiences referred to as a “trip.” Intensified colors, distortion of shapes and sounds, movement of stationary objects, and altered perceptions are all part of the LSD experience.

At one time, it was widely believed that LSD remained trapped in the spinal cord indefinitely when ingested. However, after testing this theory, researchers found the drug leaves the system completely once it clears the bloodstream.

But how long does this take, and how long does an LSD trip last? Let’s delve deeper into this psychoactive phenomenon and see exactly what LSD does to the body, how long it lasts, and more.

How Long Does LSD Take to Kick In?

How long it takes to begin feeling the effects of LSD can vary for a number of reasons, such as weight, age, and tolerance. However, according to research, the most common factors include the amount taken and the way in which the drug is ingested.

Here are some examples:

  • 100-250 micrograms via oral ingestion – When taken orally, 100-250 micrograms of LSD or “acid” can begin being felt within 30 minutes. The peak effects begin being felt in one to two hours.
  • 100-250 micrograms via intramuscular injection – While most people ingest LSD orally on paper tabs when injected into the muscle, the effects begin being felt more quickly in only 15 minutes. The peak effects occur within one hour.
  • 40-180 micrograms via intravenous injection – Taking LSD intravenously is less common, and the effects are felt almost instantly. Similar to intramuscular injection, the peak effects begin being felt in about one hour.

How Long Does LSD Last?

When taking LSD, the effects typically last 6-12 hours, depending on how much was ingested, how it was ingested, and the person’s age, weight, tolerance, metabolism, and liver health.

However, residual effects, known as “afterglow” effects, can be experienced for another six hours after the trip is over. From the initial trip to the comedown, the body may not return to its normal state for up to 24 hours.

Residual traces of LSD can be detected in urine for up to five days and in hair follicles for up to 90 days after ingestion.

What Factors Determine How Long LSD Stays in the System?

As we discussed above, there are several factors that determine how long LSD remains in a person’s system. Different people can take the same amount of LSD the exact same way at the same time and have completely different trip lengths and experiences. This is primarily due to the differences in peoples’ bodies.

Body Composition

The makeup of a person’s body is a key factor in determining when LSD will leave their system. Factors such as weight, height, muscle mass, and body fat play a major role. Since LSD attaches to fat molecules, the more body fat someone has, the longer LSD will stay in their system.

Liver Health

The liver is primarily responsible for metabolizing alcohol and other drugs, including LSD. If a liver isn’t working at its best, it may take longer to metabolize LSD and remove it from the body. Certain medications that affect the liver can also play a role.


As a person ages, their metabolism slows down, which affects their liver function. Since metabolism and liver function each play an important role in removing acid from the body, the older someone is, the longer it remains in their system.


When properly hydrated and drinking plenty of water, a person’s system is able to flush impurities from the body, including LSD, much more quickly. On the other hand, when someone is dehydrated, LSD and metabolites will stay in their system longer.

What is LSD, and Why Does It Last So Long?

LSD is short for lysergic acid diethylamide. It is a powerful, long-lasting psychoactive drug derived from a fungus commonly grown on grains, such as rye.

The chemical structure of the synthetic drug is similar to serotonin, which is a naturally occurring chemical in the brain responsible for making people “feel good.” When LSD molecules land on the brain’s serotonin receptors, the physical and visual psychedelic effects of LSD begin to occur.

LSD molecules are able to bind strongly to serotonin receptors and settle into the receptor pockets, causing the amino acids of the receptors to form a “lid” over the acid molecules. This locks the molecules in place.

The effects of LSD don’t begin to wane until the molecules become loosened and unbound from the serotonin receptors. As mentioned earlier, this process can take anywhere from six hours to 12 hours to complete, depending on the dosage, method of ingestion, and the person’s body composition.

What are the Dosage Guidelines?

For most people, a dose of 1 to 3 micrograms per kilogram of body weight is enough to produce a moderate trip.

If you haven’t used acid before, starting with a smaller dose may be a safer way to determine how your body handles the drug. Heavy doses of LSD can create intense highs that make you uncomfortable or nauseous.

Without chemical testing, it’s impossible to know how much LSD is in any product you choose to take. However, a quarter-inch tab from a blotter paper typically contains 30 to 100 micrograms.

An LSD gelatin, or “windowpane,” may contain slightly more acid per piece. They usually contain anywhere from 50 to 150 micrograms.

Liquid LSD is very potent. You should avoid taking it directly unless you know how diluted it is.

What are the Effects of an LSD trip?

LSD is a psychoactive drug. The effects of the drug often alter your perception of your environment, your body, your mood, and your thoughts. What’s real and what’s imagined become less clear during an acid trip.

The effects of an acid trip can be felt in two ways:

  • how acid affects your body
  • how acid affects your brain

Effects on the Brain/Perception

LSD creates powerful hallucinogenic effects. Your senses are heightened during a trip. Everything in your environment may feel amplified.

During an acid trip, you may see:

  •  brighter colors
  •  changing shapes
  •  trails behind objects
  •  unusual patterns
  •  “noisy” colors

LSD can also amplify your mood. If you take acid when you’re feeling good, you may feel more relaxed, happy, or content. You may also become unusually excited and joyful.

If you take acid while you’re upset or angry about something or someone, you may grow more upset or frustrated during the trip. Take your current mood and surroundings into account before you decide to trip.

Effects on the Body

During an acid trip, you may experience:

  • increased blood pressure
  • faster heart rate
  • higher body temperature
  • nausea
  • dry mouth
  • shakiness
  • insomnia

These symptoms should subside completely within 24 hours.

Are there any negative side effects or risks?

Little research about the long-term effects or risks of LSD is available, but LSD is generally considered safe and well-tolerated. The risk of death and severe consequences is low.

However, negative side effects are possible.

The use of LSD does carry risks:

  • Bad trip – During a bad acid trip, you may feel scared and confused. You may experience hallucinations that leave you terrified and distraught. Bad trips can last as long as good ones, and there’s no way to stop the trip once it begins. You can expect the effects to linger for up to 24 hours after the bad trip begins.
  • Tolerance – Tolerance to acid develops quickly. Repeated acid use may require larger doses in order to reach the same effect. However, this tolerance is short-lived. If you stop using acid for a period of time, you’ll lower your threshold for what’s necessary to trip.
  • Flashbacks – Hallucinogen persisting perception disorder is rare. It causes sensory disturbances similar to what you experience during a trip. These “flashbacks” can occur days, weeks, or even months after your last acid trip.
  • Psychotic issues – LSD use may trigger schizophrenia in people who are predisposed to the condition. However, this connection remains unclear.
  • Legal troubles – In the 1960s, U.S., state, and federal governments declared LSD an illegal, controlled substance. It remains such today. That means if you are caught with the drug, you may face fines, probation, or prison time.

Bottom Line

If you’re interested in trying LSD, be sure to know your risks — both physical and legal —before you seek out the drug. Although many people tolerate acid trips well, bad trips and other negative side effects can happen.

If you decide to try acid, ask a friend to stay with you during your trip. They should stay sober until you fully come down from the drug. If you begin to experience any negative effects, they can help keep you safe and reassured of your reality.

You should also let your doctor know if you’ve taken or will continue to take LSD. Acid can interfere with some prescription drugs, including antidepressants, so it’s important, to be honest about your recreational activity.