How Long Do Amphetamines Stay in Your System?

amphetamine pills overlaying image of clock and calendar

Amphetamines refer to a small group of central nervous system (CNS) stimulants drugs. Commonly used amphetamines include:

Amphetamines stay in the body anywhere from one to several days based on the type of amphetamine used.

When people talk about amphetamines they may be referring to an illicit amphetamine-like methamphetamine or they may also be referring to prescription stimulants like Adderall, Vyvanse, or Dexedrine. Knowing the difference can help you better understand how long amphetamines stay in your system.

Duration of Effects of Amphetamines

The effects of amphetamines can last different lengths of time depending on the drug used. The effects of amphetamines typically last for about 4–6 hours. Some prescription formulations last much longer, however. For example, Adderall XR (extended-release) contains beads that slowly release the active ingredient over 8–12 hours.

Vyvanse works for about 8–12 hours, but has a unique pharmacology. The molecule is dextroamphetamine attached to the amino acid, lysine. When Vyvanse enters the body, proteins in the blood cleave off the lysine molecule and leave active dextroamphetamine.

Methamphetamine causes peak effects within a few hours after use, and can last between 8–12 hours for most people regardless of method of administration.

Amphetamines Half-Life

The half-life of a drug is how long it takes the body to break half of it down. For example, someone who takes 10 mg of dextroamphetamine will have 5 mg still in their body 12 hours later, 2.5 mg 24 hours later, and so on.

Half-lives for common amphetamines are:

  • Amphetamine Salts: 10–13 hours
  • Dextroamphetamine: 12 hours
  • Vyvanse (Lisdexamphetamine): 1 hour, then 12 hours once converted to dextroamphetamine in the body
  • Methamphetamine: 10 hours

Vyvanse has two half-lives because it must be converted to its active ingredient, dextroamphetamine, in the body. When someone takes Vyvanse, it takes five hours to fully convert to dextroamphetamine, and the body begins metabolism of dextroamphetamine before all Vyvanse is converted to dextroamphetamine.

Methamphetamine has a half life of about 10 hours, so it stays in the blood for 50 hours. However, it may remain in some tissues of the body far longer, not being completely eliminated for 120 hours.

The half-life of a drug is almost always longer than the duration of its effects. Drugs tend to stay in the body long after their effects have worn off.

How Long Will Amphetamines Show in Drug Test?

Amphetamine salts leave the body in 60 hours, but traces of it can be detected in other ways. Amphetamine drug tests are designed to detect drug use long after the drug is gone from the system.

Urine

Amphetamine salts can be detected in the urine for three days after a single use. People who take amphetamines every day will typically test positive for nine days after the last dose. Methamphetamine is detectable for up to seven days after just one dose.

Blood

  • Amphetamine salts and dextroamphetamine stay in the blood for about 60 hours.
  • Vyvanse stays in the blood for 5 hours but is quickly converted to dextroamphetamine, so it has an effective time in the body of 65 hours. Drug tests will detect it once it converts to dextroamphetamine.
  • Methamphetamine is detectable in the blood for about 25 hours.

Saliva

Amphetamine is measurable in the saliva for the same amount of time it is in the blood, roughly 60 hours. Methamphetamine is measurable for 55 hours in the saliva.

Hair

When drugs are present in the bloodstream, they deposit into hair follicles. As the hair grows, the drug remains locked into the hair until the hair is cut. Amphetamines and other drugs can be detected in hair for roughly 90 days.

Factors Affecting How Long Amphetamines Stay in Your System

In general, using amphetamines every day will make them stay in the body for longer than a single use.

Genetics plays a role as well, but the effects are not predictable. Some modifiable factors that affect how long amphetamines are in the body include:

  • Amount used: The more a person uses, the longer it is detectable in a drug test.
  • Frequency of use: Taking amphetamines every day will cause the dose to accumulate and stay in the body longer.
  • Method of use: The method by which a person uses amphetamines does not play a big role in how long they stay in the system, but it could have a slight impact.
  • Age: In general, an older person will metabolize drugs more slowly because their liver and kidneys lose function over time. Amphetamines may last a little longer in older patients.
  • Overall health: Amphetamines are mostly metabolized by the liver, so people with liver problems will metabolize it more slowly.

False Positives for Amphetamines

Urine drug screens are prone to error, especially when looking for amphetamines. False positives happen because amphetamines have simple chemical structures and many other drugs have a similar shape. Urine drug screens can accidentally report false positives for these drugs by mistake:

  • Antidepressants (selegiline, bupropion, trazodone, fluoxetine, tricyclics antidepressants)
  • Antihistamines (chlorpheniramine, brompheniramine, pheniramine)
  • Antipsychotics (chlorpromazine, thioridazine)
  • Labetalol
  • Phentermine
  • Phenylephrine
  • Promethazine
  • Pseudoephedrine
  • Ranitidine

A positive result will be sent to another lab for confirmation. The confirmation test is called liquid chromatography-mass spectrometry (LC-MS) and is very sensitive and specific. In other words, LC-MS tests are not prone to false-positives like normal urine drug screens.

How Amphetamines Are Broken Down in the Body

Amphetamines are broken down by the liver, but some of the drug is filtered into the urine by the kidneys. There is no way to flush amphetamines or other drugs out of the body quickly. It takes time to break down amphetamines

Key Points: How Long Do Amphetamines Stay in Your System?

  • Amphetamines are a class of stimulant drugs that include both prescription and illicit substances
  • The effects of amphetamines last between 4–12 hours, depending on the type used
  • Amphetamines take at least 60 hours to leave the body, but some take up to 120 hours
  • Amount and frequency of use are the most important factors that affect metabolism

If you or someone you know abuses amphetamines, consider taking steps toward addiction treatment and recovery. The only guaranteed way to pass a drug test is not to have the drug in the body. Call The Recovery Village Ridgefield to talk about treatment options.

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Drug Aware. “Amphetamines.” Drug Aware, 2019. Accessed Aug 19, 2019.

Moeller, Karen E.; et al. “Urine Drug Screening: Practical Guide for Clinicians.” Mayo Clinic Proceedings, January 2008.  Accessed July 30, 2019.

U.S. National Library of Medicine. “Amphetamine Sulfate.” 2019. Accessed July 30, 2019.