Testing Positive for Alcohol Despite Sobriety?

Stopping drinking is hard-won, and a positive hair alcohol result afterwards can feel like it undoes the work. It usually does not. There are several well-understood reasons an EtG result can stay positive after the drinking has stopped, and most of them are about timing rather than truth.

1. EtG left over from before you stopped

Ethyl glucuronide is a metabolite of alcohol, and hair holds a historical record rather than a current one. Hair grows at roughly 0.7 to 1.5 cm per month, so a sample taken a few months after your last drink can still be made up largely of hair that grew while you were drinking.

The test is not describing today. It is describing the period during which that hair was formed.

2. Slow growth and dormant hair

Hair grows in cycles. Some follicles are actively growing, the anagen phase, while others are resting in the telogen phase, where the hair stays in the scalp without growing before it eventually sheds.

EtG from earlier drinking stays locked in those dormant hairs. If your growth rate is slow, or a higher-than-usual proportion of your hair is resting, older hair carrying EtG is still there to be sampled long after you would expect it to have gone.

3. Alcohol in everyday products you swallow

The Society of Hair Testing defines abstinence as no alcoholic drinks and no other alcohol-containing products taken in. Some liquid medicines, herbal tinctures and tonics contain alcohol, and so does mouthwash, which counts if it is swallowed rather than rinsed and spat out.

What you put on your hair is a different matter. EtG is made in the body from alcohol you have taken in, and the Society’s Consensus on Alcohol Markers records that EtG concentrations appear not to be influenced by hairspray, gel, wax, oil or alcohol-containing hair care products.

If you are being tested for abstinence, check the label of anything you swallow, and mention any products you use regularly when you attend for collection.

4. Contamination from hats and headwear

Hats, caps and other head coverings worn during your drinking period can hold residues that transfer back onto clean hair over time. Replacing or thoroughly washing that headwear removes the problem.

5. Individual differences

Two people can stop drinking on the same day and get different results three months later. Three things drive that.

How much, and how recently. Heavier or more frequent consumption leaves more EtG in the hair, and it takes longer to grow out.

Growth rate. Faster-growing hair produces clean, EtG-free hair sooner, so the sample taken is more likely to be new hair.

The proportion of dormant hair. More telogen-phase hair means more old hair still in place, and a slower fall in measured EtG.

None of that is within your control, which is exactly why a result close to the threshold deserves interpretation rather than a straight reading.

What to do about it

If you are testing for abstinence and the result does not match your experience, the useful steps are practical ones: switch to alcohol-free hair and oral products, replace headwear from your drinking period, and where the timeline matters, talk to us about the sample length before collection. Alcohol results are read against reference ranges set for 3–6 cm of hair, so unlike a drug test, the sample can’t be split into 1 cm, month-by-month segments.

Where a result carries consequences, a court matter, a treatment program, an employment condition, have it reviewed by an independent forensic toxicologist who can address these factors specifically and put the assessment in writing. The SoHT interpretive bands are the starting point for that conversation, not the end of it.

A positive result in the early months of sobriety does not diminish what you have done. Often it means the hair being tested is older than the decision you made.

Book a hair alcohol test online, or call (03) 9380 5434 to book by phone. Calls are answered by our reception staff, who look after bookings and can’t give legal advice.