Armpit Hair Drug Tests: When Labs Use Underarm Hair, How Far Back It Goes, and What Affects the Result

Updated 18 Oct 2026 · By the DrugTestAnswers editorial team

If your head hair is short, shaved or thinning, a hair drug test doesn't simply get cancelled. The collector usually moves to body hair, and underarm hair is one of the common backups. That changes the picture in ways most people don't expect: armpit hair grows on a different cycle than scalp hair, it can reflect a longer and fuzzier window of use, and the skin underneath is far more sensitive to harsh products. This guide covers how armpit hair testing works, what people try before one, what the evidence actually supports, and how to check your own status first. We may earn a commission if you buy through our links.

The honest bottom line

There is no product or routine with independent proof that it gets armpit hair past a drug test. Body hair holds drug metabolites the same basic way head hair does, and because it grows slowly, it may hold them for longer. The only sure way to pass any hair test is not using during the period the sample covers. What you can do is understand the process, avoid hurting yourself with harsh home remedies, and find out where you stand with a home test before the real one.

When a collector uses underarm hair

Most workplace hair tests ask for about 90 to 120 strands of head hair cut close to the scalp from the crown, enough to weigh roughly 100 milligrams. The collector only looks elsewhere when that isn't possible, for example when:

• your head is shaved or the hair is shorter than the lab's minimum length;
• you are bald or have very thin hair on the crown;
• there isn't enough head hair to make up the sample weight;
• religious or cultural reasons rule out cutting head hair.

Labs and employers set their own order of preference. A common order is head hair first, then chest or abdomen, then underarm, then arms or legs. Many programs avoid pubic hair. Armpit hair is short, so the collector may need to take hair from both underarms to reach the weight.

Why armpit hair can show a longer history

Scalp hair grows about half an inch (around 1.25 cm) a month, and most scalp follicles are in the growing phase at any moment. That is why a 1.5 inch head sample is read as roughly the last 90 days.

Underarm hair works differently:

• Slower growth. Body hair grows more slowly than scalp hair.
• Short growing phase, long resting phase. A much larger share of underarm hairs sit in the resting phase at any time, and they stay in the follicle for months before shedding.
• No date stamp. Because hairs of different ages are mixed together and the hair is short, a lab can't split body hair into monthly segments.

Lab literature and testing companies commonly describe body hair as reflecting up to about a year of history, sometimes stated more conservatively. The exact window can't be pinned down for any one person. In practice, this means stopping use 90 days before a test does not guarantee clean armpit hair the way people assume for head hair.

Does sweat or deodorant change the result?

The underarm is full of sweat glands, and drugs and metabolites appear in sweat. That's one reason some studies have reported higher drug concentrations in body hair, including underarm and pubic hair, than in scalp hair from the same person. Results vary by drug and by study.

Deodorant and antiperspirant don't change what is inside the hair shaft. The lab washes samples before analysis to remove surface residue like deodorant, sweat salts and smoke, then tests the hair itself. Skipping deodorant or scrubbing the armpits right before the appointment won't move a result.

Shaving your armpits before a test

People sometimes ask whether they should remove all body hair. Factually, here is what tends to happen:

• If there is no usable hair anywhere, many employers switch to a urine or oral fluid test instead.
• Some employers' policies treat deliberately removing all hair right before a scheduled collection as a refusal to test, with the same consequences as a failed test.
• Fresh shaving followed by harsh products can cause razor burn, folliculitis and broken skin.

Read your employer's policy. Being honest with the collector about why there isn't head hair is the safer route.

Product facts: detox shampoos on body hair

Hair test shampoos are written for scalp hair, and their directions assume you can lather and leave the product on for several minutes. Old Style Aloe Toxin Rid from TestClear is the one most guides discuss. What's known:

• Seller's claim: a deep-cleansing shampoo that removes residue, buildup and impurities from hair.
• Directions for scalp hair: wash with regular shampoo, apply Aloe Toxin Rid to damp hair, massage in, leave 10 to 15 minutes and rinse, repeated over the days before a test.
• Body hair: some buyers apply it to underarm, chest and leg hair in the shower. The label is built around head hair, and nothing independent shows it works on either.
• Proof: there is no independent published evidence that it beats a hair test. Reviews are personal stories.

You can view Old Style Aloe Toxin Rid at TestClear, and our Aloe Toxin Rid shampoo review and how-to guide covers the directions and limits in full.

Don't put Macujo or bleach routines on your underarms

The Macujo method uses vinegar, a salicylic acid face wash and detergent on the scalp. Underarm skin is thinner, often freshly shaved and prone to irritation. Acids and detergents there can burn and blister, and broken skin raises infection risk. Bleach is worse: never use it on underarm skin, and never mix bleach with vinegar, ammonia or other cleaners, since those combinations can release toxic gas. If any product stings, rinse with cool water and stop.

Armpit hair vs head hair at a glance

What an underarm collection looks like

A body hair collection is quick and a little awkward, but routine for collectors. You'll be asked for ID and to sign a custody form. The collector wears gloves, cleans the scissors or clippers, and cuts hair as close to the skin as possible, usually from both underarms. The hair goes into foil or a collection envelope, which is sealed and labeled in front of you, and you initial the seal. The form will note that the sample is body hair, and the lab and Medical Review Officer read the result with that in mind.

If you have very little underarm hair, the collector may combine it with chest, arm or leg hair from the same person to reach the weight, or ask you to come back after it grows. Ask questions if anything is unclear, and keep a copy of your paperwork.

Other body hair they might take

Chest and abdomen hair is often preferred over underarm hair because there's usually more of it and less sweat exposure. Leg and arm hair is used when other sites don't give enough. Beard hair is accepted by some labs. Pubic hair is avoided by many programs for privacy reasons. All of these share the same slow, mixed growth cycle, so all of them are read as a longer, undated window.

Test yourself first

A home hair follicle test lets you mail a sample to a lab and get a private result. Check the kit's instructions on whether it accepts body hair and how much you'll need, since underarm hair is short. A negative result means you can stop worrying. A positive one tells you to look at timing and your options rather than guess. See our picks for the best hair follicle drug test kits, and our page on how long it takes to pass a hair follicle test for the head hair timeline.

Prescriptions and honest answers

If you take a prescribed medication that can show up, such as an amphetamine for ADHD or an opioid after surgery, keep your paperwork. Positive lab results are usually reviewed by a Medical Review Officer, who can verify a valid prescription before anything goes to the employer.

Our sourcing

Collection practices reflect published guidance from hair testing laboratories and the Society of Hair Testing. Hair growth cycles come from dermatology references. Product details come from TestClear's product page. We don't test products on samples or publish testimonials; see our editorial methodology.

Tests this page doesn't apply to

Do not use anything on this page for DOT-regulated tests (CDL drivers, rail, transit, pipeline, maritime), FAA aviation testing, federal employee programs, military testing, or court, probation and parole testing. Tampering with those programs can count as a refusal and may be illegal.

Disclaimer and support

Informational only, not medical or legal advice. Tampering with a drug test may be illegal and can count as a refusal or failed test. The only guaranteed way to pass is abstinence. Free, confidential help is available 24/7 from the SAMHSA National Helpline at 1-800-662-4357. In a crisis, call or text 988.