So, your boss asked you to get a hair drug test. Or maybe your ex. Or your parent. Or your future employer. And you have heard all kinds of rumors about what this test can detect, and for how long. So, let’s take a few moments to dispel the rumors and explain the truths.
How far does a hair test go back?
Hair drug testing goes back much, much longer than urine drug testing. In fact, when you ingest drugs, it goes into the hair follicle, and then into the strands themselves, where they stay, pretty much forever. Hair grows at a rate of approximately .5 inches per month. So, in theory, if your hair was 18 inches long, and you tested the ends of the strands, then you could find drugs consumed more than 3 years ago!
But, don’t panic. Nobody tests the ends of the hair (except the police, who can do whatever they wish). There is only one standard for this test – 1.5 inches of hair, cut from the root. The non-root end is discarded. In fact, we recommend that you watch the technician perform the test and ask them to cut off and discard the length beyond the first 1.5 inches. This ensures that the 1.5 inches equates to approximately 3 months (give or take) of history.
What drugs can be detected in the hair?
There are 5 types of hair tests available:
- 5 Panel Hair Follicle Drug Test $175.00
- 5 Panel Hair Follicle Drug Test plus Expanded Opiates $200.00
- 9 Panel Hair Follicle Drug Test $50.00
- 12 Panel Hair Follicle Drug Test $475.00
- Hair Alcohol Test $600.00
Does body hair show a longer period of drug use?
Now, what if you don’t have hair on your head that is at least an inch and a half? Well, in that case, we can test underarm, leg, or chest hair. Occasionally, we test beards. And, uh, no, we cannot get the specimen from any other place on your body other than those I already mentioned!
There is a lot of debate about the pace of growth of body hair. Many people are concerned that an inch and a half of body hair will retain drug residue for a much longer period of time, if in fact the body hair grows much slower than the head hair.
The reality is that body hair and head hair grow at the same rate. The difference is that body hair tends to stop growing at a shorter maximum length. In both head and body, new hair replaces dormant strands and pushes them out. You know how you shed some hair all the time? This is because a new hair pushed out the old one, which stopped growing and became dormant. When a hair is dormant (i.e., not growing), no new drug deposits can get into it. It can stay there 1 to 4 months, so in theory, head OR body hair can reveal drugs that go back further than 90 days, depending on the person. However, only 10 to 15 percent of your strands are in this dormant phase, so the risk is minor.
On the other hand, there are many anecdotes (and a few labs) that report that body hair can pick up drugs for up to 12 months. Although there are no scientific studies that have shown this conclusively, you’d be wise to consider it when thinking about how to interpret the results. The bottom line is: the 90 day mark is an educated estimate, but there is no calendar in your hair. Accordingly, a positive result doesn’t indicate the dates that the drugs were used. In conclusion, your hair retains your drug use history, but not in the same way that, say, a browser retains your search history.
A hair test for a bald man. Really?
Finally, sometimes Health Street gets calls from people who want a hair test, but they have no head or body hair. A guy recently told us, “I shave from head to toe.” Well, how did he think we were going to perform the test? We are still trying to figure that one out!
No hair means you can’t get a hair drug test.