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Amphetamineshairqlscn

Published: August 9, 2026Updated: August 16, 2026

A hair follicle test that detects the presence of amphetamine drugs in your hair, providing a long-term history of drug use.

Quick summary

{"This test uses a hair sample to check for amphetamine use over the past 90 days or longer","Hair testing can detect drug use that occurred weeks to months before the test","The test is commonly used for workplace drug screening, legal proceedings, or medical monitoring","A positive result indicates amphetamine exposure but does not indicate impairment","Hair color, ethnicity, and hair treatments may affect test results"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
40798-1
Short code
Amphetamines Hair Ql Scn
Synonyms
Amphetamines Hair Ql Scn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
screen
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

The Amphetamine Hair Test is a screening test that detects the presence of amphetamines (including methamphetamine, MDMA, and related stimulant drugs) in a hair sample. Unlike blood or urine tests that only show recent drug use, hair testing can reveal drug exposure over an extended period, typically the past 90 days or longer, depending on the hair length analyzed.

How does it work?

When a person uses drugs, traces of the substance enter the bloodstream and are incorporated into the hair follicles as the hair grows. A small sample of hair (usually about 100-120 strands) is cut from the scalp area and sent to a laboratory for analysis. The laboratory uses specialized equipment to detect and measure amphetamine compounds in the hair shaft.

How is the sample collected?

Sample collection is simple, quick, and non-invasive. A small amount of hair is cut from the back of the head, close to the scalp. The sample is typically about the width of a pencil and 1.5 inches long. If head hair is not available, body hair (such as from the arm or chest) may be used as an alternative.

What do the results mean?

A negative result means no amphetamines were detected at or above the cutoff level. A positive result indicates that amphetamines were detected in the hair sample. It's important to note that a positive test does not indicate when the drug was used, the amount used, or whether the person was impaired at the time of testing. Second-hand exposure to drugs may sometimes produce low-level positive results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings2

Frequently asked questions

How long does amphetamine stay in hair?
Hair testing can detect drug use for up to 90 days or longer, depending on the length of hair sampled. Each inch of hair approximately represents one month of history. For example, a 3-inch hair sample can reveal drug use from the past 3 months.
Can hair treatments affect the test results?
Yes, certain hair treatments can potentially affect test results. Chemical treatments such as bleaching, dyeing, or perming may degrade drug residues in the hair, potentially leading to false-negative results. However, modern testing methods are often able to detect drugs even after some hair treatments.
Can I test positive from second-hand exposure?
It is possible but rare. Significant second-hand exposure (such as being in a room where methamphetamine is being smoked) may potentially cause a low-level positive result. However, laboratory confirmation testing can often distinguish between actual use and environmental exposure.
Will shaving my head help me pass the test?
No, this will not work. Even if head hair is shaved, body hair can still be tested. Additionally, hair regrows quickly, and new hair will still contain any drug use that occurred before the shaving.
What happens if my test is positive?
If the initial screening test is positive, the laboratory typically performs confirmation testing using a more specific method (such as mass spectrometry) to verify the result. If confirmed positive, the result is reported to the requesting party (employer, physician, or legal entity) according to the testing protocol.
Can prescription medications cause a positive result?
Certain prescription medications containing amphetamines (such as Adderall, Dexedrine, or medications for ADHD) may cause a positive result. It is important to disclose all prescription medications to the testing facility before the test. The confirmation test can often differentiate between illicit amphetamines and prescription medications.
  1. 1
    Mayo Clinic Laboratories - Hair Drug TestingSource
  2. 2
    Substance Abuse and Mental Health Services Administration (SAMHSA) - Hair Testing GuidelinesSource
  3. 3
    American Association for Clinical Chemistry - Hair Testing for Drugs of AbuseSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy