Accuracy of Hair Drug Test Questioned in High Profile Cases

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A lot of people think the hair drug test is foolproof.

Certainly, you hear this all the time from the makers of these tests. Most doctors agree, the test can’t be beat.

Oh really?

Well, a number of high-profile cases and research studies in North America, the UK and Canada have forced this question to the surface recently.

We’ll see how this play out, but it’s clear now that everyone is NOT in agreement that the hair follicle test is 99+% accurate, as test makers claim. Including the test lab at the heart of a child custody controversy in Canada.

Christine Rupert Loses Her Two Girls

Christine Rupert courtesy of TheStar
Christine Rupert courtesy of

widely publicized case involving a Toronto, Ontario woman by the name of Christine Rupert raises doubts about the accuracy of the hair drug test for cocaine.

Christine’s children, now 18 months and 6 months old, were permanently removed from her custody at birth because of her suspected cocaine use. She claims to have been drug-free since 2007, well before the birth of the first child in question.

Hair drug tests performed at Sick Kids’ Motherisk lab came back positive. Rupert is adamant that the tests were wrong and has spent years trying to get her girls back, to no avail.

According to, the hair drug test was used to outweigh the results of more than 70 other tests that Christine took:

The last time Christine Rupert saw her daughters was in a dingy church basement in Kitchener, surrounded by awkward and emotional reunions between other parents and their kids. It was September 2008. Molly, a tentative 18-month-old with fine brown hair and wide eyes, sat as if glued to her mom’s lap. Emily, 6 months, mainly snoozed in her car seat.

Both girls…were removed at birth because of their mom’s suspected cocaine use, though both newborns tested negative for drugs. They remained in foster care based, primarily, on hair tests that showed Rupert was a heavy cocaine user — a finding she fiercely denied and was going to great lengths to disprove.

Rupert acknowledged she had previously done cocaine recreationally, at parties, a few times a year. However, she was adamant she had not taken the drug since fall 2006.

During the case, Rupert had produced nearly 70 clean urine tests, cut ties with an abusive ex, and had ample money and space to care for the girls. But in April 2009, a judge made both Molly and Emily wards of the province. They were adopted by separate families, without access to their mom.

The main reason the judge gave for his decision: Positive cocaine hair test results from the Motherisk laboratory at the Hospital for Sick Children.

Christine agreed to subsequent hair tests, but they all came back positive – in trace amounts that varied widely.  She continued to claim she was completely drug-free during all of these tests.

“They kept saying, ‘Stop doing drugs.’ I kept saying, ‘I’m not on fricking drugs.  Somebody please help me,’” she recalls. “I kept going back for these stupid tests. But these stupid tests kept coming back worse. I was digging a hole.”

Apparently, Christine isn’t the first to suffer that fate.

In another high-profile case, Toronto mom Tamara Broomfield got her cocaine-related conviction overturned back after fresh evidence cast doubts over the science of the hair drug test performed by Motherisk labs, which was used to convict her.

Lab Questions The Reliability of Its Own Test

According to an earlier Star report, a British High Court, a U.S. government department and international toxicologists have all raised questions about the reliability of hair-strand tests that are routinely accepted in child welfare cases in Ontario as evidence of parental drug or alcohol abuse. These are the same tests used in the US to deny employment for drug use.

Ironically, the manager of the Motherisk laboratory that tested Christine Rupert, Joey Gareri, is one of the chief critics of the test’s reliability.

According to a 2011 research paper written by Gareri and a Motherisk lab co-worker,

The risk for false-positive results appears high when monitoring a female population.

Two other studies published in scientific journals suggested there may be a racial bias to hair tests, because drugs appear to be incorporated more readily into darker-colored hair. There is also evidence that the way substances are incorporated into the hair of a single individual may vary from strand to strand.

In the U.S., the Dept. of Health and Human Services made a decision in 2008 that more analysis was needed before adding hair tests to its mandatory guidelines for workplace drug testing.

Update: as of March, 2015, the Motherisk hair testing lab has been shut down due to its inability to product consistent and accurate test results.

To learn more about the latest proven ways to beat the hair drug test, read my summary.