When does meth kick in?

The time it takes for meth to kick in varies by HOW you take it. However, once methamphetamine is absorbed, the biological effects are the same regardless of the route of exposure. More on meth onset here.

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There are a number of factors which affect the onset of meth and its effects on the body. One important factor which influences drug onset is mode of administration. Methamphetamine hydrochloride can be inhaled (smoked), snorted, injected, or ingested, with injection and inhalation producing the most rapid onset and ingestion resulting in delayed onset.

In general, once methamphetamine is absorbed, the biological effects are the same regardless of the route of exposure. Peak blood methamphetamine concentrations occur shortly after injection, a few minutes after smoking, and around 3 hours after oral dosing. More here on how d-methamphetamine works, with a section for your questions about why people use meth or problems with meth at the end.

Meth active ingredients

The main ingredient in meth is methamphetamine hydrochloride. This chemical is present as wither a yellow or white crystalline powder or as “ice,” a large, usually clear crystal of high purity. What are the components of these forms of meth?

Free base (“methamphetamine base”), is the initial product of meth and is a liquid at room temperature. The hydrochloride salt is produced from the free base by bubbling hydrogen chloride gas through it. However, methamphetamine also contains one optically active carbon atom. Consequently, there are two isomeric forms of methamphetamine, called d-methamphetamine and l-methamphetamine. The d-isomer is more potent than the l- isomer; most all of the methamphetamine produced by illegal labs is the d-isomer. d-methamphetamine is a controlled substance in the United States and is only available by prescription for legitimate medical uses in the treatment of ADHD or short term treatment of obesity.

Factors that influence meth onset

For a drug to work, it must enter the body, dissolve into a solution, be absorbed by the body and the distributed to sites of action. And in the process, a number of different factors can affect the rate at which drug onset begins. These include:

  1. Drug bioavailability – Intranasal and smoked methamphetamine are well absorbed. Although intranasal or smoked routes may decrease the risk of transmission of blood-borne diseases, exposure to methamphetamine and the possibility of drug-related complications remain substantial.
  2. Drug form – Meth comes in several forms, including powder, crystal, rocks, and tablets. When it comes in the crystal form it is called “crystal meth.” The type of meth you take will influence onset of effects.
  3. Mode of administrationHow meth is abused affects onset of effects. Routes of methamphetamine administration are varied, with prior reports of exposure via nasal insufflation, IV administration, ingestion of liquid formulations, and a single case report of intravaginal exposure. Each of these effect onset of effect. Also, the producers of meth change the way that drugs dissolve in order to modify solubility characteristics, and therefore slow or quicken drug onset. Here is a general list of fastest to slowest drug delivery forms:


  • Liquids, elixirs, syrups
  • Suspension solutions
  • Powders
  • Capsules
  • Tablets
  • Coated tablets
  • Enteric-coated tablets 


When does meth start working?

Methamphetamine is readily absorbed from the GI tract and absorption is usually complete by 4-6 hours.  How long can meth last? Effects persist for 6 to 12 hours and may persist up to 24 hours after large doses. Peak plasma levels of meth occur within 1 to 3 hours, varying with the degree of physical activity and the amount of food in the stomach.

When does meth peak?

Peak blood methamphetamine concentrations occur shortly after injection, a few minutes after smoking, and around 3 hours after oral dosing. Following oral administration, peak methamphetamine concentrations are seen in 2.6-3.6 hours and the mean elimination half-life is 10.1 hours (range 6.4-15 hours). Following intravenous injection, the mean elimination half-life is slightly longer (12.2 hours).

When does meth wear off?

The effects of methamphetamine on humans are profound. The stimulant effects from methamphetamine can last for hours. Often the methamphetamine user remains awake for days. As the high begins to wear off, the methamphetamine user enters a stage called “tweaking,” in which he or she is prone to violence, delusions, and paranoia.

Risks of meth addiction

Meth use can quickly lead to addiction. For one thing, its long half life and duration of effects are attractive for their euphoric effect. However, you can quickly become physically dependent on meth and it causes tolerance. People who abuse meth start needing to take more of it to get the same initial high. People who usually eat or snort meth might start to smoke or inject it to get a stronger, quicker high. Additionally, the psychological need for meth can compel continued use, especially when underlying psych-emotional issues go unresolved.

People trying to quit taking meth can experience any of these common effects:

  • Be unable to feel happy
  • Feel a very strong need to take meth
  • Feel angry or nervous
  • Get really tired but have trouble sleeping

When does meth kick in questions

We hope to have answered questions about the onset of meth’s effects in this article. But if you still have questions about meth effects and risk of using it, please write them in the section below. We will do our best to answer them promptly.

Reference Sources: OEHHA: Methamphetamine
TOXNET: d-methamphtamine
PublicSafety: Methamphetamine – How It’s Made
NIDA: DrugFacts – Methamphetamine
NIDA for teens: Methamphetamine (Meth)
NHTSA: Methamphetamine (and Amphetamine)
NCJRS: Methamphetamine: A Dangerous Drug, A Spreading Threat
Justice: Meth Awareness
NCJRS: The National Methamphetamine Drug Conference
NCBI: Bottoms Up: Methamphetamine Toxicity from an Unusual Route
About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.


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    1. Hi Rozanne. How long does methamphetamine stay in the body depends on a number of factors, such as urine pH levels, amount taken, how frequently the drug is used, body mass, rate of metabolism. Urinalysis can turn up a positive result for meth within 1-4 days, but heavy and/or chronic use can extend this time frame.

  1. Wanted to ask a question about Meth and how long would it take to show up in a blood test if i had to swallow it all in a baggie cause of the situation I was in.

    1. Hi Kerry. Meth can be detected up to 3 days in blood tests, while the detection period for binge or/and chronic users might be longer.

  2. actually the release of methamphetamine does help someone with ADD. ADD is a disorder caused buy the chemical imbalance of dopamine and or serotonin and norepinephrine. So any stimulant (of which almost all do) that cause our neurons receptors to allow more of these chemicals to attach to a receiving neurons dendrites will help the symptoms of “ADD” such as lack of focus and cluttered mental state. In fact, Adderall is comprised of several amphetamine isomers

  3. I accidentally took meth yesterday morning that someone had put in a headache powder medicine. I also took 2 Aleve. I almost immediately felt funny. Even went to the Dr due to high bp and heart rate, couldn’t urinate. It has now been 36 hours and I still have dry mouth, numbness,tingling all over , heart burn, weak and just feel weak. I only drank about half the cup with goody powder in it. How much longer is this going to last. I do not smoke ,use any drugs or alcohol.

  4. When I was a user, I smoked it. All I can say about the difference between smoking and snorting is that snorting, while having a lasting affect (compared to cocaine), has an instant “Wow” effect. Smoking is, IMO, a more general come on, but a very long lasting one. I often said that it was the one drug that “euphoria” was actually an appropriate term, until it turned you in Mr. Hyde…and it will, trust me. Stay Away!

  5. I suffer from ADHD and would never ever try meth as a way to cope with it. I don’t take medicine for mine because I’m way to under weight for it, but I do take anxiety medicine and it has helped tremendously to get me through school. School is a challenge for anyone suffering with ADHD. It’s mellowed me out a lot so I can concentrate on lectures and not freak myself out. Just a thought. 🙂

  6. Andres. Im 22 about to be 23. I also suffer from ADHD. I’m no doctor but self medicating is never the best road. Not to be rude to dawn but their statements sound like highly uneducated opinions. Meth is the most addictive drug I ever had the misfortune of being hooked on. I had to move across the country from texas to west virginia to get away from it. Its been two years and i still battle the addiction daily. Smoking is the most addictive route of administration. Steer clear I beg you. I lost my family my closest friends and after 3 months of use I was homeless just scraping up enough to get high. It ruins life…

  7. Andres I also have adhd and I have tried to smoke meth as well for self medicating my adhd and it doesn’t have the same effects on us as it does the rest of the population. Because meth is a stimulant it doesn’t affect us. I’ve never drank it in coffee as you have although I have thought about it. I normally smoke mine I crush it up into a very fine powder and then smoke it off of aluminum foil with a straw. It does clear your head and you can focus a little bit more but mostly it will make you lazy. Unless you do a lot I mean it takes a whole bunch for us to get the same side effect as the rest of the world. Also I have been smoking it on and off since October 2013 and I’ve probably smoked it 20 times just to be able to get through those long boring lectures without going crazy( only someone with adhd can understand the going crazy statement) I can go weeks days even months without doing it again. I don’t think we get the same “addiction” level as everyone else. My twin sister is adhd as well and she hasn’t become addicted either. Also my best friend is adhd and she hasn’t become addicted either. I’m not saying it’s not possible for you to get addicted to meth don’t get me wrong. Every drug has the possibility of addiction I’m just saying since we treat adhd with stimulants naturally it’s just harder in my opinion to become addicted. Especially since I know 3 people who are adhd and smoke meth and do not have to use it on a daily basis. I currently do not take any adhd drugs to treat my adhd I have learned to deal with the craziness. But I also don’t want to fail college so I mainly use it when I “need” to get through a hard lecture or test without all the mental interruptions adhd causes us naturally. I would love to hear from you again since your post was 6 months ago to see what has become of your meth use.

  8. M.E.T.H. (more evil than hell) don’t even attempt trying it and stay as far away from it as you possibly can. although it can be enjoyable exciting and give a one of a kind highest high ever, this stuff will not only destroy your life but also adversely affect and potentially destroy anyone close to you. I speak from experience of losing absolutely everything and doing prison time because of this drug. not worth it!

  9. Stay as far away from it as you possibly can. Hear it’s around, run as fast as you can in the other direction. The old story is after the first time you try Heroin you are hooked. Not my experience, but most definitely my experience with meth. Don’t think what you see about it on TV, or read about it, is just some anti-drug hype. Meth is a killer, it shatters every aspect of your life, just take it from an ex-addict to meth. I don’t believe in God. I prayed to him to get me off the drug, that’s how much destruction it causes. Anything to give you strength to get off it. And I’m going to be completely honest, you’re not in for a fun ride, but the end result of kicking the habit is worse every day of torture getting off it and NOT COLD TURKEY. I meant to say also that the end result of torture is worth it when quitting.

  10. Hello Andres. You are not alone! And you have a long life ahead of you. Have you consulted with a doctor? We’d suggest this as a first step. You can also call the trusted hotline number listed on our website to talk with an addiction treatment consultant 24-7. Meth use can lead to many more problems than it solves.

  11. good afternoon, today I decided to started to take crystal meth orally to treat my severe AdHd i know tgis is a drastic meqsure but the truth is a feel i am about to go crazy. I cant concentrate on anything i am really disorganized and cant stick on a plan task or project but for short periods. my life is down the gutter Iam 22 yrs old. i used a very small amount just some powder from.the crystals that formed a weak one inch line. i disolved it and drank ot with coffee. efdect are yet to take effect. besides taking real medication any other suggestions or advice.

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