How long do amphetamines stay in your system?
Half of the amount of amphetamine that you take is eliminated by your body in under 11 hours (amphetamine elimination half life). But heavy and chronic amphetamine use can be detected in your system up to one week after your last dose. Learn more about how long the effects of amphetamine last, amphetamine detection times and drug testing for amphetamines here.
How do you take amphetamines?
The most common forms of amphetamines are pills, tablets, or capsules, which are swallowed. The less frequent forms, liquid and powder, can be injected or snorted but using this routes of administration increases risk for addiction to amphetamines. This is because getting high on amphetamines increases your risk of mental dependence on them. In fact, although physical dependence on amphetamines is possible, psychological and mental dependence is more frequent and known to increase risk of amphetamine addiction.
What are amphetamines used for?
Medically, amphetamines are prescribed by doctors treating ADD and ADHD. But amphetamines have also been used to treat narcolepsy, have been prescribed as a weight loss medication, and rarely, have been prescribed to treat depression.
Peak levels and half life of amphetamines
The duration of a single dose effect of amphetamines lasts from 2 to 4 hours. Residual effects of amphetamines can last longer. Peak plasma concentrations of amphetamine occur approximately 3 hours post-dose for l-amphetamine. The amphetamine metabolite peaks at 12 hours.
The mean elimination half-life for d-amphetamine is between 9.77-11 hours. Following intravenous injection, however, the mean elimination half-life of the amphetamine metabolite is slightly longer at 12.2 hours.
Amphetamine drug testing
How long do amphetamines stay in the body? Detection periods for amphetamines vary. This is because rates of metabolism and excretion are different for each drug, each use and vary by individual. Approximations are due to variables such as drug metabolism and half-life, person’s physical condition, fluid intake and method and frequency of use. This is why detection periods for amphetamines should be viewed as estimates. Cases can always be found to contradict these approximations.
In general, amphetamines (including methamphetamine) have a drug and detection period of 1-2 days in urine testing, although some sources claim to be able to detect amphetamines up to 4 days after you take them. Initial testing cutoff concentrations are at 1,000 ng/mL with a confirmation test at 500 ng/mL. Blood concentrations are generally used to distinguish therapeutic use from abuse.
False positive tests for amphetamine
Many “over-the-counter” (OTC) and prescription medicines contain chemicals that are structurally related to amphetamine. These compounds can be identified in the standard amphetamine screening procedures or mistaken for amphetamines. In fact, the Physicians’ Desk Reference provides a list of more than 350 medications that may produce positive test results for amphetamines. If you are taking cough suppressants, antihistamines, antibiotics or other OTC or prescription medications, be sure to report these to drug testing staff. Positive test results for amphetamines can occur and you should be clear about
Amphetamines and addiction
Amphetamines can be very addictive. In fact, large doses and long term use of amphetamines can cause higher tolerance levels and dependence, which lead to addiction. Physical dependence on drugs like Adderall require detox and withdrawal periods (Adderall withdrawal how long?) So how do you know if you have problems with amphetamines or not? Well, if you think that you have a problem, you probably do. Please send us your questions, and we will help you find an answer. Feedback, comments, and experience is also welcomed in the comment section below.
Reference sources: SAMHSA/CSAT Treatment Improvement Protocols: Chapter 9, Drug Testing as a Tool
National highway Traffic Saftety Administration fact sheet on methamphetamine (and amphetamine)
FDA fact sheet on Adderall
Photo credit: Brookhaven National Laboratory