Hair Follicle Test Positive for Meth: What the Result Means and What Happens Next

Updated 21 Oct 2026 · By the DrugTestAnswers Editorial Team

A hair follicle test that comes back positive for meth can feel like the end of the road, especially if a job offer or a family situation depends on it. Before you panic, it helps to know exactly what that word "positive" means on a hair report, what had to happen in the lab for it to get there, and which steps are still open to you. Some people really did use and need a plan for what's next. Others are dealing with a prescription, a contaminated home or a report they don't understand. This page walks through all of it in plain language, from the numbers on the report to the phone call from the medical review officer, retesting, and how long it takes for hair to grow out clean. We may earn a commission if you buy through links on this page.

The short answer

A positive meth result on a hair test means the lab found methamphetamine in the hair above a set cutoff, after washing the sample, and confirmed it with a second, more exact method. In most workplace programs it also means the amphetamine metabolite was found at a meaningful level, which points to the drug having passed through your body rather than just landing on your hair. It does not say how much you used, on which day, or whether you were impaired. A confirmed positive is hard to overturn unless there's a valid medical explanation or a real problem with the sample or paperwork.

What "positive" actually means on a hair report

Hair labs work in two stages. First comes a screening test, usually an immunoassay, which is fast and cheap and looks for the amphetamines family as a group. If the sample screens below the screening cutoff, it's reported negative and the process stops. If it screens above, the lab moves on to confirmation using mass spectrometry, which identifies each compound by its molecular fingerprint and measures how much is there.

Only the confirmed number decides the final result. On many reports you'll see methamphetamine and amphetamine listed separately with a value in picograms per milligram of hair (pg/mg), alongside the cutoff the lab used. A result above the confirmation cutoff for methamphetamine, with amphetamine also present where the program requires it, is what turns into a reported positive. Our page on whether a hair follicle test can detect meth covers typical cutoff ranges, and our hair strand test results guide explains each line of a report.

Why the amphetamine number matters so much

When your body breaks down methamphetamine, part of it turns into amphetamine. That conversion only happens inside the body, so finding amphetamine alongside methamphetamine supports actual use. Many programs require the amphetamine level to reach its own threshold before they'll call the sample positive for meth. If your report shows methamphetamine with little or no amphetamine, that pattern can be worth raising, because it's one of the ways reviewers think about outside exposure. It isn't proof of anything on its own, but it's a question worth asking.

What a positive result can't tell anyone

• When you used. A standard sample, the 1.5 inches closest to the scalp, covers roughly the last three months as a block. Unless the lab cut the hair into segments, there's no date attached.
• How often or how much. Higher numbers loosely go with heavier use, but hair color, cosmetic treatments and individual biology shift the figure a lot. No honest chart turns a pg/mg value into a number of uses.
• Whether you were impaired at work. Hair reflects past exposure, not your state on any given shift.
• Use in the last week or so. Hair takes about seven to ten days to grow far enough out of the scalp to be cut, so the most recent days usually aren't in the sample at all.

How a meth positive gets from the lab to an employer

In most regulated or well-run workplace programs, the lab doesn't send a positive straight to the employer. It goes first to a medical review officer, usually shortened to MRO, who is a licensed doctor trained to review drug test results. The MRO's job is to check the paperwork and give you a chance to explain the result before it's reported. Here's the usual order of events:

1. The lab confirms the result and reports it to the MRO, not to HR.
2. The MRO or their staff try to reach you, usually by phone, often within a day or two. Answer, or call back quickly. If they can't reach you after reasonable attempts, the result may be reported anyway.
3. During the interview, the MRO asks whether you take any medicines that could explain the result and may ask for proof, such as a pharmacy record or a call to your prescriber.
4. If there's a valid medical reason, the MRO reports the test as negative to the employer, and the details stay between you and the MRO.
5. If there isn't, the MRO reports it to the employer as a verified positive. What happens next depends on the employer's policy.

Smaller employers and some private testing setups skip the MRO step and send results directly. If you're not sure how your program works, ask who reviews positive results before they're released.

Prescriptions that can lead to a meth result

A few legitimate medicines can produce methamphetamine or a related compound in hair. The most direct one is Desoxyn, a prescription methamphetamine used for ADHD and, rarely, weight management. Selegiline, a medicine used for Parkinson's disease and in a skin patch for depression, breaks down into the levo form of methamphetamine and amphetamine. Over-the-counter nasal inhalers that contain levmetamfetamine also produce the levo form, though normal use rarely reaches hair cutoffs.

Labs can run a chiral test, which separates the levo form from the dextro form found in illegal meth. If you take one of these medicines, tell the MRO right away and have your prescription details ready. Adderall, Vyvanse and Dexedrine are different: they produce amphetamine, not methamphetamine, so they shouldn't by themselves cause a meth positive. If you take them, still mention them, because they explain an amphetamine result.

Contamination: when you didn't use but the hair says otherwise

Meth smoke leaves residue on walls, carpets, furniture and anything else in the room, and that residue can stay for a long time. People who live with someone who smokes meth, or who moved into a home where it was used or made, sometimes worry their hair could pick it up. Labs know about this, which is why they wash samples before testing and lean on the metabolite requirement and cutoffs. Those safeguards work well for light contact. They're less certain with heavy, long-term exposure, and research on children removed from homes where meth was made has found the drug in their hair.

If you believe contamination explains your result, say so to the MRO, explain the living situation, and ask about the wash results and the amphetamine level. Be realistic, though: reviewers hear this explanation often, and without supporting facts it's unlikely to change a verified positive. Our page on secondhand smoke and hair tests covers how labs handle outside exposure.

Can you challenge or retest a positive hair result?

Often, yes. When the collector cuts your hair, they usually take enough for the lab to keep a portion in storage. In many programs you can ask for that retained or split portion to be sent to a different certified lab for a second test. Some things to know:

• Ask fast. The window to request a retest is usually short, often a matter of days after the MRO tells you the result.
• Expect to pay. The person requesting the retest generally covers the cost, though some employers reimburse it if the second lab can't confirm.
• The second lab only checks presence. A retest usually looks for the drug at or above its detection limit, not the original cutoff. It confirms that the drug is there; it doesn't start the whole process from scratch.
• A fresh sample is a different question. Employers aren't usually required to accept a new hair sample you collect yourself, and a new cut a few weeks later covers almost the same months anyway.

You can also ask for copies of the chain-of-custody form and the lab report. Mistakes in labeling, missing signatures or a broken seal are rare, but they're the kind of thing that can matter.

What employers usually do after a verified positive

There's no single rule, but most outcomes fall into a few groups:

Many employers that hair test also have a waiting period, often six months to a year, before a candidate with a positive result can apply again. If you're told no today, it's worth asking politely what that period is.

How long until a hair test is clean again

Head hair grows roughly half an inch a month on average. The standard sample is the first inch and a half from the scalp, so after you stop using, it takes roughly three months for the clean hair to fill that whole length, plus the week or so it takes new hair to grow out of the scalp. Some people grow faster or slower, and a few strands are always in a resting phase, so many labs and counselors suggest allowing a bit longer than 90 days to be safe.

Body hair is less predictable. It grows more slowly and spends longer in its resting stage, so a body hair sample can reach back well past three months. If your head hair is very short or shaved, a collector may take body hair instead, and that can delay how soon you'd test clean. Our page on how far back a hair drug test goes explains the timing in more detail.

Things that make a meth positive worse, not better

• Shaving your head before a retest or new test. Collectors will simply take body hair, which can hold an even longer history.
• Bleaching or relaxing your hair in a panic. Harsh chemicals can lower some readings, but not predictably, and badly damaged hair stands out at collection. You can also burn your scalp.
• Mixing household chemicals. Never combine bleach with vinegar, acids or other cleaners. That can release toxic chlorine gas.
• Bringing an altered sample or someone else's hair. Collectors cut hair from your head in front of you, and tampering is treated as a refusal, which is usually worse than a positive.
• Ignoring the MRO. Not answering usually means the result is reported without your side of the story.

Meth is one of the easiest drugs for hair to catch

Methamphetamine binds strongly to melanin, the pigment inside hair, and it reaches hair at much higher levels than drugs like THC. That's why a meth positive is usually solid, and why stories about shampoos "beating" a meth hair test deserve extra suspicion. It's also why the best time to learn your status is before a test rather than after one.

Find out where you stand before the next test

If you've stopped using and you're wondering whether your hair has caught up, a private home hair test can answer that before an employer sees anything. You cut a small sample, send it to a lab and get a result back, usually within a few days of the lab receiving it. Our home hair follicle test kit guide explains the options, and the TestClear hair kit linked on this page is one of them. Testing yourself at the 90-day mark, and again a few weeks later if needed, takes the guessing out of when to reapply.

Product facts: Old Style Aloe Toxin Rid

Old Style Aloe Toxin Rid is a detox shampoo sold by TestClear for people facing hair drug tests. The maker's directions call for repeated washes every day over several days, building up to a set number of washes before the test, and it's also the shampoo most Macujo method versions finish with. You can see the product page and full directions on the Old Style Aloe Toxin Rid page at TestClear.

Here's what's true and what isn't. TestClear says the shampoo is designed to deep-clean the hair shaft. There's no independent, published research showing that it, or any shampoo, reliably brings methamphetamine inside the hair below a lab cutoff, and with meth's strong pull toward melanin the bar is especially high. We'd never tell you it guarantees a pass. It also does nothing to change a result that's already been reported. Our Aloe Toxin Rid review and how-to guide sets out the maker's claims, the schedule and the evidence side by side.

About Macujo and Jerry G routines

You'll see these routines mentioned constantly. The Macujo method layers vinegar and a salicylic acid face wash with a detox shampoo over several days, and the Jerry G method adds bleach and hair dye. Neither has been tested in any published study, and both carry real risk of chemical burns and hair breakage. If you look into them anyway, never mix bleach with acids or cleaners, keep everything away from your eyes, and stop if your scalp blisters or bleeds. Our Macujo method guide lays out the steps and the safety warnings honestly.

Questions to ask after a positive result

• Who reviewed the result, and did a medical review officer sign off?
• What were the methamphetamine and amphetamine levels, and what cutoffs were used?
• Was the sample head hair or body hair, and how long was it?
• Is there a retained portion, how long is it kept, and how do I request a retest?
• Can I get copies of the chain-of-custody form and the lab report?
• If the offer is withdrawn, how long before I can reapply?

If meth use is part of the picture

Sometimes a positive test is the moment someone realizes using has gotten harder to control. Meth can take a toll on sleep, heart health, teeth, mood and relationships, and stopping often brings a crash of tiredness, low mood and cravings that can last for weeks. That's normal, and it passes. Counseling approaches such as contingency management and cognitive behavioral therapy have good evidence for stimulant use, and many employers' assistance programs can connect you to them confidentially. You don't need to have it all figured out to make a call.

Tests this page doesn't apply to

Don't try to alter, avoid or tamper with a DOT, CDL, FAA, federal, military, court, probation or parole test. Those programs follow their own rules, and interfering with a sample can bring legal consequences on top of the result itself.

Where this information comes from

This page draws on published hair testing research, the federal guidelines for drug testing programs and medical review officer practice, and laboratory guidance on cutoffs and confirmation. Cutoffs and procedures vary between labs and programs, so the paperwork from your own test always wins over any general guide, including this one.

Disclaimer and support

This page is general information, not medical or legal advice. If you'd like help with substance use, the SAMHSA National Helpline is free, confidential and available 24/7 at 1-800-662-4357. If you're in crisis or thinking about harming yourself, call or text 988.