Understanding the Detection Window for Hair Strand Testing

Why Hair Strand Testing Outperforms Blood and Urine Tests for Drug and Alcohol Detection

During a recent webinar on October 23rd, hosted by Dr. Salah Breidi (Toxicologist & Court Expert Witness) and Simon Dean (Chief Marketing Officer for AttoGroup), experts discussed the growing preference for hair strand testing over traditional blood and urine tests for detecting drug and alcohol use.

While urine and blood tests are still widely used in some settings, such as cases of drunk driving and workplace drug and alcohol testing, hair testing is proving to be a more reliable and comprehensive method for family law cases, including child custody and care proceedings. Learn more about our drug and alcohol testing services here.

With advancements in drug and alcohol testing, the accuracy and precision of hair testing continues to improve. Here’s why hair testing stands out:

1. Extended Detection Period

One of the main advantages of hair testing is its ability to detect substance use over an extended period—several months. In contrast, urine tests only detect recent use from the last 1–3 days, while blood tests provide an even shorter detection window. This makes hair testing the preferred option for long-term assessments, such as legal investigations, civil investigations, workplace testing, or addiction monitoring.

Hair drug and alcohol testing with segmental analysis offers the unique advantage of identifying patterns of substance use over specific time periods, enabling a month-by-month assessment that provides greater insight into consumption history than other testing methods.

For alcohol detection, hair testing offers a longer detection window, showing consumption patterns over several months, while urine tests detect only recent use within a few days. Similarly, hair drug testing allows for identifying drug use over months, whereas urine drug testing only captures recent use.

2. Non-Invasive and Easy to Administer

Unlike blood tests, which require needles, or urine tests, which can be invasive, hair testing is a simple and painless procedure. A small sample of hair is cut, making the process straightforward and comfortable for the individual being tested.

3. Tamper-Resistant

Urine testing can be easily tampered with, as individuals can substitute clean samples or use adulterants. Hair strand testing, however, is much harder to manipulate because the substances are embedded in the hair itself. 

Even if some individuals shave their head, body hair from the armpits and chest can still be used to explore drug use over several months.

4. Comprehensive Substance Detection 

Hair testing can detect a wide range of substances, including both drugs and alcohol. 

For drug testing, hair samples can be analysed for methamphetamines (including MDMA/Ecstasy), opiates (including heroin, morphine, and codeine), cannabis, cocaine, amphetamines, and benzodiazepines (like Valium and Xanax), also known as MOCCAB or the 6-panel test. Recent advancements in hair testing can detect an even broader range of substances, including steroids, synthetic cannabis (often called spice or legal highs), and new psychoactive substances (NPS) like psilocybin (magic mushrooms).

For alcohol testing, two markers are commonly investigated: Ethyl Glucuronide (EtG) and Ethyl Palmitate (EtPa). Both EtG and EtPa identify alcohol consumption over an extended period, which urine testing often misses.

5. Avoids Short-Term Abstinence Evasion

A key limitation of urine and blood tests is that individuals can evade detection by abstaining for a short period before testing. Hair testing reveals substance use over a much longer period, preventing short-term abstinence from affecting the results. 

Understanding Discrepancies Between Urine and Hair Testing Results

Dr. Salah explained a common question: “Why does hair drug and alcohol testing show positive results when urine testing shows negative?” This discrepancy occurs due to the different detection windows of each method. Urine tests typically identify substance use within the last 1–3 days, while hair testing provides a longer history, which is particularly important in cases like care proceedings where individuals may be tested weekly or biweekly.

For instance, if someone consumes cocaine and alcohol on a Sunday and is tested the following Wednesday, the urine test is likely to show negative results for drugs and alcohol due to its limited timeframe. However, hair testing can detect past substance use that urine tests miss, offering a more comprehensive view of an individual’s drug and alcohol history. Learn more about our testing methods here.

Why the Legal System Prefers Hair Strand Testing 

In summary, hair strand testing (HST) offers numerous advantages over blood and urine testing. It provides a longer detection window, is less prone to tampering, less invasive and detects a broad range of substances.

For those who missed the webinar and want to learn more about the benefits of hair testing and its role in modern drug and alcohol detection, you can watch the full webinar here. 

If you would like to request a quote for our hair drug test, please visit this link.

For more information on upcoming CPD webinars, head here to sign up or watch on demand.

AttoLife remains committed to supporting legal professionals with accurate, reliable, and court-admissible drug and alcohol testing services, ensuring that every case is as robust and well-informed as possible. 

Please get in touch with our team for any inquiries about, hair strand drug and alcohol testing, nail drug and alcohol testing or blood drug and alcohol testing. 

Watch The Hair Drug Testing Webinar