Lysergic acid diethylamide (LSD), or acid, lasts up to 12 hours in the body and is metabolized within 48 hours.

When you take it orally, it’s absorbed by your gastrointestinal system and channeled into your bloodstream. From there, it travels to your brain and other organs.

It only stays in your brain for about 20 minutes, but the effects can last considerably longer depending how much is in your blood.

Healthline does not endorse the use of any illegal substances, and we recognize abstaining from them is always the safest approach. However, we believe in providing accessible and accurate information to reduce the harm that can occur when using.

People typically begin to feel the effects of acid within 20 to 90 minutes. The effects peak after around 2 to 3 hours, but this can vary significantly from person to person.

How long acid takes to kick in and how intense the effects are depend on several factors, including:

An acid trip can last anywhere from 6 to 15 hours. Some lingering effects, referred to as “afterglow,” can last for another 6 hours after that. If you count the comedown, you could be looking at 24 hours before your body returns to its normal state.

As for the actual effects, they can include:

The same factors that influence how long acid takes to kick in also influence how long the effects linger. The intensity and duration can also be affected by over-the-counter or prescription medications.

Compared to other drugs, acid can be harder to detect because it’s quickly broken down in the liver. And since only a small amount is needed to get the desired effect, most people only ingest small amounts.

The specifics of how long it’s detectable depends on the type of drug test used:

  • Urine. Acid is quickly transformed into inactive compounds by your liver, leaving about 1 percent of unchanged LSD in your urine. Most routine drug tests are urine tests and can’t detect LSD.
  • Blood. In a 2017 study, LSD was detectable in blood samples 16 hours after participants had been given 200 micrograms of the drug. For participants given a dose half that size, LSD was detectable 8 hours after administration.
  • Hair. Hair follicle drug tests are useful for detecting past drug use and can detect a number of drugs up to 90 days after its use. But when it comes to LSD, there’s not enough data to say how reliably a hair follicle test can detect it.

There are several things that can affect how long acid is detectable in a drug test.

These include:

  • Your body composition. Your height and amount of body fat and muscle plays a role in how long acid is detectable. The more fat cells a person has, the longer drug metabolites linger in the body. Body water content also matters. The more you have, the faster the drug is diluted.
  • Your age. Your liver function and metabolism slows with age. Younger people metabolize acid faster than older adults.
  • Your liver function. Your liver plays a key role in metabolizing acid. If you have a medical condition or take a medication that impairs your liver function, LSD will be harder to eliminate.
  • Time between use and testing. Acid is eliminated from the body quickly, which makes it hard to detect. The sooner the drug test is performed after acid is taken, the more likely it is to detect it.
  • How much you take. The more you take, the longer it will be detectable. How often you take it can also affect detection time.
  • Your metabolism. The faster your metabolism, the faster acid leaves your system.

Acid is eliminated from your system quickly, but if you want to try to speed up the process, there are things you can do.

Give the following a try:

  • Hydrate. Acid and its metabolites are excreted through your urine. Staying hydrated before, during, and after taking acid can help get it out of your system faster.
  • Stop taking acid. Timing matters when it comes to testing for LSD, and the sooner you stop taking it before a drug test, the less likely it will be detectable.
  • Exercise. It’s not the quickest fix, but exercise can boost your metabolism. A combination of aerobic exercise and lifting weights has the most impact on metabolism.

Considering trying acid? There are a couple of big things to know before taking the leap.


Some people who use LSD report having bad trips and lasting emotional effects. There’s no surefire way to know whether your trip will be good or bad, but your risk of experiencing longer-lasting effects, such as flashbacks, increases when you take a high dose or use it often.

Using LSD frequently or in large amounts also increases your risk of developing a tolerance or psychological addiction to it. It can also increase your risk of a rare condition called hallucinogen persistent perception disorder.

Keep in mind that LSD can have extremely powerful effects that can alter your perception and judgement. This might make you more likely to take risks or do things you otherwise wouldn’t.

Safety tips

If you’re going to try LSD, there are a few things you can do to make it less risky:

  • Don’t do it alone. Make sure you have at least one sober person around who can intervene if things take a turn.
  • Consider your surroundings. Make sure you’re in a safe, comfortable place.
  • Don’t mix drugs. Don’t combine LSD with alcohol or other drugs.
  • Go slow. Start with a low dose, and allow plenty of time for the effects to kick in before considering another dose.
  • Pick the right time. The effects of LSD can be pretty intense. As a result, it’s best to use it when you’re already in a positive state of mind.
  • Know when to skip it. Avoid LSD or use extreme caution if you have a preexisting mental health condition, such as schizophrenia, or take any medications that might interact with LSD.

How long acid stays in your system depends on a number of variables. If you’re concerned about drug testing or the effects of acid, stop taking it right away.

If you’re worried about your LSD use, talk to your healthcare provider or contact the Substance Abuse and Mental Health Services Administration at 1-800-622-4357 (HELP).