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Family Physician
Family Physician, Doctor
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Experience:  Emergency Medicine and Family Practice for over 26 years
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Can a hair follicle test determine exactly how often a drug

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Can a hair follicle test determine exactly how often a drug was used and exactly what the drug was ie codeine not morphine.

Or does it just come back that an opiate was used in the last 3 months?

A hair drug test will not be able to determine how often a drug was used. It can tell that a drug was taken and the relative amount, but it cannot tell if there were a few episodes of higher drug use or more frequent use of lower amounts. It is possible to segment the hair into smaller time periods, such as each of the last three months instead of the three months together, but this is not routinely done, and even if done, does not say how often the drug was used within that month.

Like urine drug tests, the initial test is a screening test that does not differentiate the various opiates. When there is a positive screen, a confirmatory test is typically done, such as gas chromatography/mass spectrometry (GC/MS). If it is expected that an opiate is present, the doctor may choose to not perform the confirmatory test. But if the confirmatory test is done, it will differentiate between the various opiates.

Dr. D. Love, Doctor
Category: Medical
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Experience: Family Physician for 10 years; Hospital Medical Director for 10 years.
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Thank you for your question:

The other expert's answer regarding hair testing missed a few important details. Hair testing does not use the 2 step method of screening and confirmation testing commonly used with urine testing. The hair tests are done directly with GC/MS or similar testing that CAN differentiate between the various opiates.

Specifically for codeine and morphine, these two opiates are related and since codeine does metabolize to morphine, it is not always possible to be certain which drug was the cause of a positive morphine test.
Customer: replied 3 years ago.

Does the follicle test state how much of a substance was used,leading perhaps to further investigation??

You accepted the other expert's answer - do you want me to continue to assist you?
Customer: replied 3 years ago.

yes please

Customer: replied 3 years ago.

yes please,I will rate you when I get a response.

Customer: replied 3 years ago.

It seems that once I rate someone I can't ask them more questions....

I'm sorry for the delay - I was offline for a few minutes

No - there is really no way to determine with any certainty the amount of a drug that someone used. While the report will likely contain an actual concentration - this would be more important in following repeated tests to see that the concentration was declining over time as someone stopped using the drug. You can't directly determine the dose or frequency of use by the concentration.
Family Physician, Doctor
Category: Medical
Satisfied Customers: 12816
Experience: Emergency Medicine and Family Practice for over 26 years
Family Physician and 3 other Medical Specialists are ready to help you
Customer: replied 3 years ago.

This is the reply I got back from a hair testing lab to which I posed the same questions:

We can estimate when, by making the assumptions for head hair samples:

1. Hair grows at 1cm/month

2. It take 2weeks for the hair to become available for sampling.

3. Only 10-15% of the hair is not growing

Can you determine how many times a drug was used and what that exact drug codeine as opposed to morphine?

We can determine which drug is used as the parent drug and metabolites are ‘locked’ in the hair as the hair grows. The drugs and metabolites are released in the extraction process and measured by LC-MS/MS and GC-MS/MS both highly sensitive and selective techniques, which allow us to determine and quantify which opiate i.e. codeine or morphine.


They can ESTIMATE the approximate time (in the range of several weeks) IF they do segmental hair analysis. This is more expensive and involved than traditional testing since the specimen is cut into segments and each segment is then tested separately. This is typically used to confirm that someone who had a positive, and is within the 3-4 months since stopping, that their newest hair is "clean" while they still could have positives on traditional testing.

As for the issue of how many times - this is NOT possible.