Can a Hair Follicle Test Detect Opiate Use? Which Opioids Show Up, How Far Back, and What Labs Look For

Updated 17 Oct 2026 · By the DrugTestAnswers editorial team

Yes. Opiates are one of the five drug classes on almost every hair follicle panel, so a standard hair test can detect opiate use from roughly the last three months. What it actually finds depends on which opioids the lab includes: the basic panel looks for codeine, morphine and a marker that's specific to heroin, while many employers add synthetic and semi-synthetic painkillers such as oxycodone, hydrocodone or fentanyl. This guide walks through what's covered, how the test separates one opioid from another, how one-time and prescription use are handled, and where hair-cleansing shampoos fit in. We may earn a commission if you buy through our links.

The short answer

A hair follicle test can detect opiate use, and it's usually better at showing a pattern of use than a urine test is. Urine shows a few days. A standard 1.5 inch section of head hair, cut close to the scalp, reflects roughly 90 days, because head hair grows about half an inch a month. Whether a particular drug shows up comes down to three things: whether it's on the panel, how much and how often it was used, and whether the amount in the hair clears the lab's cutoff.

"Opiates" vs "opioids" on a lab report

Labs use the two words differently, and the difference decides what gets tested:

• Opiates are the natural compounds from the opium poppy and the drugs closest to them: morphine, codeine and heroin (which the body turns into morphine).
• Semi-synthetic opioids are made from those natural compounds: oxycodone, oxymorphone, hydrocodone and hydromorphone.
• Synthetic opioids are built from scratch in a lab: fentanyl, methadone, tramadol and meperidine. Buprenorphine is usually grouped with these for testing purposes.

A basic "opiates" line on a 5-panel test is aimed at the first group. The other groups are only reported if the panel lists them, which is why two people can take "an opioid hair test" and be screened for very different things.

Which opioids each common hair panel covers

Panel contents vary by lab and by employer. If you're curious what yours covers, the collection paperwork or the employer's policy normally lists the drug classes. Our guide to 12-panel hair tests goes through an expanded menu line by line.

How the lab tells heroin from codeine from a painkiller

Hair testing runs in two stages. First the lab washes the sample to remove surface residue, then grinds or dissolves it to release the drugs locked inside the hair shaft. An immunoassay screen looks for the opiate class in general. Any sample above the screening cutoff goes to confirmation by mass spectrometry, which identifies each compound by its exact mass, so the final report names specific drugs instead of a whole class.

The heroin marker is the important one. When heroin enters the body it breaks down into 6-acetylmorphine (6-AM or 6-MAM) and then morphine. 6-AM isn't produced by codeine, by prescription morphine or by poppy seeds, so finding it in hair points to heroin specifically. In urine 6-AM only lasts hours, but in hair it's locked in and much more stable, which is one reason hair is considered a strong test for heroin use over time. Our page on screen vs confirm results explains the two-step process in more detail.

Fentanyl and hair tests

Fentanyl is now the opioid many programs worry about most, and it isn't part of the classic opiate screen because its structure is completely different from morphine's. Labs that test for it look for fentanyl itself and its breakdown product norfentanyl, and the amounts involved are tiny, so cutoffs are set much lower than for morphine. If fentanyl matters for your situation, the only way to know if it's covered is to check whether it's named on the panel. A lot of street drugs are now contaminated with fentanyl, which means someone who believes they only used one substance can still test positive for it.

Can one use of an opiate show up in hair?

Sometimes, but it's much less certain than regular use. Hair cutoffs are set to catch repeated use, and a single dose of a short-acting opioid may leave too little in the hair to cross the line. Several factors push the odds up or down:

• Dose and potency. A large dose leaves more behind than a small one.
• The drug itself. Heroin's 6-AM marker is relatively easy to confirm when present. Very low-dose drugs like fentanyl need sensitive methods.
• Hair color. Opioids are basic drugs that bind to melanin, the pigment in hair. Studies have found higher concentrations in dark hair than in light hair after similar use.
• Timing. Hair needs about a week to grow up past the scalp, so use in the last several days usually isn't in a scalp-cut sample yet.
• Cosmetic treatment. Bleaching and perms can damage the hair and lower drug levels, but labs can often see the damage. See our page on perms and hair tests.

For the time it takes for use to grow out, see how long it takes to pass a hair follicle test.

Poppy seeds and codeine medicines

Poppy seeds are a well-known cause of morphine and codeine positives in urine. Hair is generally much less affected because the amounts from food are small and don't build up in hair the way regular drug use does, and hair cutoffs for opiates are set with that in mind. It isn't impossible, especially with very large amounts eaten often, but a single bagel isn't a realistic explanation for a confirmed hair positive. Codeine cough syrups and acetaminophen-with-codeine tablets are different: they're real codeine and will show as codeine (and some morphine) in a hair test. That's normal and is handled through the medical review process below.

If you take an opioid with a prescription

A confirmed positive doesn't go straight to an employer. It goes to a medical review officer (MRO), a doctor who calls you and asks about medicines. If you have a valid prescription that explains the result, the MRO typically reports it to the employer as negative. Keep your pharmacy name, prescriber and fill dates handy. The MRO may still flag a safety concern for certain jobs, and a prescription won't explain a drug you weren't prescribed, such as heroin's 6-AM marker. Don't stop a prescribed painkiller suddenly because of a test, since stopping abruptly can cause withdrawal. Talk to your prescriber first.

What a hair test can't tell

• It can't say whether you're impaired now. It reflects use over weeks and months.
• It can't pin down an exact date. Labs avoid dating a single use from hair.
• It can't measure a dose. Levels give a rough sense of heavier versus lighter use, but hair varies too much between people for an exact figure.

Lab cutoffs for opiates are reported in picograms per milligram of hair. Our cutoff levels table lists typical screening and confirmation values by drug class.

Product facts: Old Style Aloe Toxin Rid

People researching opiate hair tests often run into Old Style Aloe Toxin Rid, a shampoo sold by TestClear. Here's what is and isn't known:

• What TestClear claims: a deep-cleansing shampoo meant to strip residue and buildup from the hair and scalp.
• The maker's directions, briefly: wash first with a regular shampoo, work Aloe Toxin Rid into damp hair and scalp, leave it on for 10 to 15 minutes, rinse, and repeat over several days before the test.
• What isn't proven: no independent published study shows it removes drugs from inside the hair shaft or gets anyone past a hair test, and nothing changes the fact that opioids are measured inside the hair, not on it. It is not a fix for a heroin or fentanyl result.

You can see Old Style Aloe Toxin Rid at TestClear if you want to read the product page yourself. Our Aloe Toxin Rid review and how-to guide covers the claims and the gaps in the evidence.

Know where you stand first

If you're unsure what an upcoming test would show, a home hair test kit is the more useful first step. You send a small sample to a lab and get a report by drug class, usually including opiates. It tells you whether there's anything to worry about before a shampoo or anything else enters the picture. Our guide to the best hair follicle drug test kits compares the options.

If opioid use is getting hard to manage

Opioid dependence is a medical condition, and treatment with medicines such as buprenorphine or methadone works well for many people. These are prescribed treatments, and a properly documented prescription is handled through the MRO like any other. Carrying naloxone (Narcan) can reverse an overdose and is sold without a prescription in US pharmacies. The SAMHSA helpline below can point you to local treatment for free.

How we put this page together

Panel contents and the testing process come from published lab menus and forensic toxicology research on drugs in hair, including work on 6-acetylmorphine and melanin binding. Product directions are summarized from TestClear's own product page. We don't test products ourselves; our editorial methodology explains how we source.

Tests this doesn't apply to

Nothing on this page is for DOT-regulated testing, FAA aviation testing, federal employee programs, military testing, or court, probation and parole testing. Trying to beat those tests can count as a refusal and may be illegal.

Disclaimer and help

Informational only, not medical or legal advice. Tampering with a drug test may be illegal and can count as a refusal or a failed test. The only sure way to pass is not to use. For free, confidential help 24/7, call the SAMHSA National Helpline at 1-800-662-4357. If you're in crisis, call or text 988.