Everything You Need to Know About Hair Follicle Drug Tests

If you have ever worked for a rehabilitation centers, or faced a court-ordered screening, chances are you have heard about drug testing. Among all testing methods available today, one of the most accurate and tamper-resistant is the hair follicle drug test.

Unlike urine or saliva tests that only show recent use, hair tests can reveal a 90-day history of substance use. This makes them popular among employers, law enforcement, and even parents seeking peace of mind.

In this guide, we will break down everything you need to know from how the test works to what it can detect, plus tips to prepare and common myths debunked.

What is a hair follicle drug test?

A hair follicle drug test (also called a hair drug test) analyzes a person’s hair sample to detect traces of drugs or their metabolites. Drug metabolites are the chemical by products left behind after your body processes a substance. These metabolites travel through your bloodstream and get trapped inside the growing hair shaft.

Because hair grows slowly (about half an inch per month), the test can identify drug use over an extended period up to three months or longer.

Why it’s so popular

Employers, courts, and rehabilitation centers prefer hair testing because:

• It’s extremely difficult to cheat or tamper with.
• It has a long detection window compared to urine or saliva tests.
• It offers scientifically verified accuracy.

In short, it is the gold standard for detecting long-term or repeated drug use.

How does a hair follicle drug test work?

Hair follicle drug testing follows a step-by-step process designed to maintain integrity and precision.

1. Collection

A trained technician cuts about 100–120 strands of hair from the crown of your head. The sample must be close to the scalp and about 1.5 inches long, representing roughly 90 days of growth.

If you don’t have enough head hair, body hair (from the arm, leg, or chest) may be used instead.

2. Laboratory analysis

Once collected, the hair sample is sent to a certified laboratory. There, it goes through:

• Decontamination: The hair is washed to remove surface impurities (like shampoo, sweat, or smoke).
• Initial Screening (ELISA): Detects potential drug presence.
• Confirmatory Testing (GC-MS or LC-MS/MS): Confirms any positive results with near-perfect accuracy.

This process can detect a wide range of substances, including illegal drugs and prescription drugs, making it crucial to disclose any legitimate medications beforehand.

3. Reporting

Within 1 to 3 business days, results are sent to the requesting organization or Medical Review Officer (MRO). The MRO may contact you if your results show positive traces, to verify any legitimate prescriptions.

What drugs can be detected?

Hair follicle drug tests can identify a wide range of substances. The most common include:

• Benzodiazepines (Xanax, Valium)
• Barbiturates
• Methadone
• Synthetic opioids (Oxycodone, Fentanyl)
• Synthetic cannabinoids (K2, Spice)

Pro Tips: Ask which type of drug panel (e.g., 5-panel, 10-panel) will be used for your test—this determines which substances are screened.

Detection window: How long does it go back?

Hair follicle testing provides one of the longest look back periods of any drug test.

• Typical detection period: Up to 90 days (based on 1.5 inches of hair).
• For body hair: Can show use for up to 12 months, as body hair grows more slowly.
• For recent use: Drugs need about 5–10 days after ingestion to become detectable in new hair growth.

Why 90 Days?

Because hair grows at an average rate of 0.5 inches per month, labs test only the first 1.5 inches of the strand. This represents the most recent three months of growth.

So, if you used a drug yesterday, it likely won’t show up right away but it will appear once that hair grows out a little.

How accurate is a hair follicle drug test?

Hair tests are extremely accurate often considered the most reliable form of drug testing available.

• Confirmatory testing (GC-MS or LC-MS/MS) ensures false positives are rare.
• External contaminants (like second hand smoke) are removed during lab washing.
• Metabolites are embedded inside the hair shaft, not just on the surface.

Even if you have dyed or bleached your hair, labs can often still detect metabolites unless the treatment severely damages the hair structure.

They are uncommon but can occur if:

• The sample was contaminated before washing.
• Certain medications or medical conditions interfere with analysis.

When in doubt, always request a confirmatory retest or consult with a Medical Review Officer.

How to Prepare for a Hair Follicle Drug Test

The truth is: you can’t easily “beat” a hair follicle test. However, preparation can make the process smoother.

• Disclose prescriptions: Provide documentation for any legitimate medications.
• Avoid harsh chemical treatments: Bleaching, coloring, or perming can affect the test but not guarantee a negative result.
• Maintain normal hygiene: Regular shampooing and cleanliness are enough. No need for “detox shampoos,” which don’t work scientifically.

• The technician will cut hair from a discreet area.
• The process is painless and takes less than 10 minutes.
• Avoid wearing wigs or extensions that might complicate collection.

Hair Follicle vs. Other Drug Tests

If an employer wants to know if someone has been using drugs consistently, hair testing provides the clearest picture.

Legal and Employment Implications

Hair follicle testing is widely used in:

• Pre-employment screenings (especially in transportation, healthcare, and safety-sensitive roles)
• Random or periodic workplace tests
• Court-ordered programs, such as probation or child custody disputes
• Substance abuse recovery programs

You generally have the right to:

• Know which drugs are being tested
• Request a re-test if you dispute results
• Provide proof of legitimate prescriptions

Common Myths About Hair Follicle Drug Tests

Let’s bust a few popular misconceptions:

#1: Shaving Your Head Helps You Avoid the Test

Wrong. Labs can use body hair samples, which often reveal an even longer history of drug use.

#2: Detox Shampoos Work

Most “detox shampoos” only clean the hair surface. Drug metabolites live inside the hair strand, beyond the reach of any shampoo.

#3: Second hand Smoke Causes Positive Results

Not true. Labs distinguish between metabolized drug residues and external contamination.

#4: Colored or Dyed Hair Always Fails

Hair treatments might slightly affect metabolite concentration, but confirmatory testing ensures accurate detection regardless of color or style.

Interpreting Test Results

Hair follicle test results come in one of three categories:

• Negative: No drugs detected above the cut off level.
• Positive: Drugs found at or above the threshold limit.
• Inconclusive: Sample was insufficient or contaminated may require retesting.

Employers or legal authorities usually receive official lab certified results, and you may also receive a copy for your records.

Final Thoughts: Understanding Hair Follicle Drug Tests

Hair follicle drug tests are among the most reliable methods for detecting long-term drug use. They provide a comprehensive view of a person’s substance use over the past 90 days, making them particularly valuable for employers, legal authorities, and rehabilitation programs.

While hair tests cannot detect very recent drug consumption, their accuracy, resistance to tampering, and extended detection window make them a trusted choice for organizations requiring objective results.

If you are scheduled for a hair follicle drug test, it’s important to:

• Understand the process and what to expect during sample collection.
• Be transparent about any prescribed medications or medical conditions.
• Maintain healthy habits, as there is no quick way to “beat” the test.

By staying informed and prepared, you can approach the test confidently and ensure your results are interpreted accurately.

Reach Out to Find Luxury Rehab

Hair follicle drug tests are a reliable method for detecting long-term substance use, often used by employers and legal authorities. If you’re preparing for a test or concerned about your results, it’s essential to approach the situation with clarity and support.

At Find Luxury Rehab, we understand the challenges associated with substance use and the importance of privacy and comfort during recovery. Our curated network of luxury rehabilitation centers offers:

• Personalized Treatment Plans: Tailored programs addressing individual needs, including medical detox, therapy, and aftercare.
• Confidentiality and Privacy: Discreet settings ensuring your journey remains private and secure.
• Holistic Healing Approaches: Integrating traditional therapies with wellness practices like yoga, meditation, and nutrition counseling.

Whether you’re seeking assistance for yourself or a loved one, taking the first step toward recovery is crucial. Explore our platform to discover top-rated luxury rehab centers that align with your needs and values.