How Long Does LSD Last And Are LSD Flashbacks Real?

How Long Does LSD Last And Are LSD Flashbacks Real?

If you’ve heard of LSD, often called Acid, you’ve probably heard about visual hallucinations, a feeling of euphoria, or the dreaded flashback trip on the drug. But people are less likely to talk about how long LSD can last in your body or the ongoing side effects of LSD use.

The problem is, you need that information if you want to be safe using LSD, and you deserve to understand how the drug works and how long it’s likely to last before you ever consider taking it.

It’s also important for people who don’t take LSD and who aren’t looking to take LSD to understand how this drug works and how long it will last because that can make you a better advocate, better able to spot LSD use in action, and better able to help friends and family members who might have started using this drug.

Like most drugs, there’s a lot more to consider than just saying no, and the better informed we all are, the easier it will be to stay safe and deal with the issues of LSD and other drug use head on, instead of hiding them behind closed doors and not getting the help we need and deserve.

If you want to know more about how long LSD lasts, what it does, and the long-term side effects of use, you’re in the right place. Let’s get started.

How Long Does LSD Last After You Take It?

How Long Does LSD Last After You Take It?

LSD is considered a long-lasting drug, lasting up to 12 hours and sometimes even longer, depending on your metabolism and dose.

This drug is so long-lasting that it’s been the subject of study since most drugs with similar effects, including other hallucinogens, don’t last nearly that long. The result of those studies was that LSD stays in your serotonin receptors instead of being cleared normally, which can help explain both the long duration and some of the intensity of the drug’s effects.

For most people, LSD takes effect within half an hour to an hour. LSD molecules are similar in size and shape to serotonin, which is why the drug can interact with your serotonin receptors.

Once LSD makes its way to your serotonin receptors, it bonds with them. That means that it won’t just go away on its own. Instead, LSD molecules must be displaced by something else in the synapse, or come disconnected, which can take between 6-15 hours on average.

Most people won’t experience symptoms for more than 12 hours. However, if your liver isn’t functioning normally, you have other metabolic differences, or you are taking certain medications, you may have symptoms for longer than that.

Normally, once LSD leaves the serotonin receptor, it’s quickly filtered out of your bloodstream by your liver, which means that it doesn’t last very long in your body after symptoms begin to fade.

That said, when the drug reaches its peak intensity and how long the most intense symptoms last is highly variable from person to person and time to time. Your experience with LSD once is no guarantee of having a similar duration or experience the second time.

It’s also common for people to gradually increase their dose of LSD with further use because you can develop a tolerance to this drug.

How Long Is LSD Detectible?

LSD doesn’t appear in typical tests because it’s removed from your body quickly after the symptoms wear off. It might be caught in a normal test if you take the test while the drug is still active, but not usually otherwise.

However, LSD is highly detectable using other tests, including a specific LSD drug test, blood tests within a day or two of taking the drug, and hair follicle tests for a couple of months after taking the drug.

Supposedly, LSD is also detectible in spinal fluid long after you stop taking the drug, possibly permanently. However, because this is an illegal drug and spinal fluid testing is very rare and usually only done when looking for certain chronic diseases, there isn’t a lot of data on this possibility.

The quickest and easiest way to not have detectible levels of LSD in your system when taking a drug test is not to take the drug at all.

It’s also important to remember that a failed drug test isn’t always disqualifying for your job, especially if you’re upfront about the issue and willing to talk about your use and potentially get into a treatment program to avoid LSD or other drug use becoming an issue in the future. This isn’t always true with all jobs, but it’s better to be upfront about the problem and deal with it head-on if you suspect there might be an issue.

Are There Side Effects After You Take LSD?

Yes, there can be.

The most common long-term side effect of LSD use is what’s called a flashback. These are different from the kind of flashback you would get if you had PTSD or other mental health conditions, and they don’t refer to a flashback to previous events or sudden intense memories. Instead, an LSD flashback is a sudden return of the symptoms of LSD use, including an altered sense of time and senses, euphoria, difficulty sleeping, and other symptoms.

LSD flashbacks are relatively rare but unpredictable and can happen to anyone who has used LSD. While flashbacks are supposed to get less frequent in the people who get them, they can happen even years after you stop taking LSD.

Some people never get flashbacks, but it’s impossible to know if you will until you do.

Another possible long-term side effect of LSD is that people who use LSD are slightly more likely to develop schizophrenia, especially if they start using LSD young or in their 20s, which is when the symptoms of schizophrenia are mostly likely to develop.

Lastly, while hallucinogens like LSD are being studied for therapeutic use in some areas, long-term use of LSD, or high doses of LSD, can also come with an increased risk of developing depression or anxiety, possibly related to the overactivation of serotonin receptors.

The risk of depression or anxiety is lower and less well-studied than with other party drugs like ecstasy or cocaine, but it is still there, and you should be aware of it if you’re considering taking LSD.

What Kind of Drug Is LSD?

LSD is a hallucinogen, a class of drugs known to cause hallucinations.

Most hallucinogens are illegal and are primarily used recreationally, like LSD. LSD is of particular note, though, because it’s stronger and longer lasting than most other hallucinogenic drugs. It’s also easier to take than many alternatives, like psilocybin mushrooms or mescaline, because it doesn’t have the same nausea side effects and typically doesn’t have an unpleasant taste, unlike other naturally derived hallucinogens.

All of those factors mean that LSD is somewhat more likely to be abused compared with other hallucinogens and that people who try LSD once are more likely to come back and use it again compared with other hallucinogens.

Side effects for LSD include difficulty sleeping, reduced appetite, nausea, fevers, etc.

What Are The Common Side Effects Of LSD?

Like any drug or medication, it’s also important to understand the common side effects of LSD use. In this case, since there isn’t a verified therapeutic use for LSD yet, we’re going to list all of the effects of LSD, intended and not, as side effects because that’s really what they are, side effects of ingesting this drug.

  • Dry mouth
  • Depression
  • Anxiety
  • Paranoia
  • Euphoria
  • Hallucinations
  • Rapid mood swings
  • Intense emotions
  • Synesthesia
  • Bizarre behavior or comments
  • Difficulty sleeping
  • Intense energy
  • Reduced appetite
  • Nausea
  • Vomiting
  • Fevers
  • Flushed skin
  • Hot flashes
  • Altered sense of self
  • Altered sense of time
  • Tremors

It’s important to remember that some people may have other side effects, more side effects, or more extreme versions of common side effects, depending on their metabolism, medications, and the unique chemistry of their body and brain.

Signs Someone Is Using LSD

There are a lot of potential signs that someone is using LSD or another party drug, so we’re only going to touch on a few of them here. These are some of the best signs for telling if someone is using LSD and some of the easiest to spot:

  • Dilated pupils
  • Bizarre behavior
  • Rambling speech
  • Loss of appetite
  • Large amounts of energy at unusual times
  • Flushed skin
  • Increased body temperature
  • Disorientation
  • Not being able to track conversations or situations around them

These can also be signs that something is seriously wrong and that the person in question needs medical attention. If you suspect someone is taking LSD or similar drugs, it’s better to ask them about it than to assume that’s what they are doing.

If they seem confused by the question, are unwilling to answer, or are unable to answer, it may be a good idea to take them to get medical attention. Even if they are taking LSD and not having a medical emergency, they may be safer under the care and supervision of medical professionals.

Feeling Out Of Control? Here’s How To Get Help

While LSD on its own isn’t normally considered addictive, in the sense that it doesn’t create a chemical dependence and people are usually better able to control how and when they take the drug, that doesn’t mean you can’t lose control over your use.

If you take LSD and are starting to feel less in control, like you need to take it more and more often, or even just like you want help for your LSD habit, you’re in the right place.

It’s okay to admit that you need help if you do—even brave.

If you’re ready to stop using LSD and want professional help to get you through the process and help you learn why you were using it in the first place and how to stop and avoid feeling like you need to use it in the future, contact Epiphany Wellness. Our experts will use proven methods to help you figure out what’s happening and how you can live a happier, healthier life without needing mind-altering substances like LSD.



  1. Holland K. How Long Does Acid Last? What to Expect. Healthline. Published July 24, 2022. Accessed December 1, 2022.
  2. Nichols H. Scientists discover why LSD “acid trip” lasts so long. Published January 27, 2017. Accessed December 1, 2022.
  3. T B. What to Know About LSD Use. Verywell Mind. Published March 5, 2022. Accessed December 1, 2022.

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