Can you still do a hair drug test if I am bald?

By John Hawes | Last updated: August 23, 2018

Yes, a hair drug test may be conducted using head or body hair.

Most testing facilities require a hair sample of approximately 100 milligrams and 1.5 inches in length to conduct hair drug testing.

Approximately 120 strands of hair are needed to satisfy this minimum requirement for testing. If placed flat, this would equal about 1 cm in width of hair. If gathered together, the swatch of hair would be about the circumference of a pencil. For individuals with very curly hair, the amount collected for sampling would be about the size of a regular cotton ball.

If you are bald or have limited hair on your head, a sample may be collected from your chest, underarm, leg, or face. Collection preference is given to body hair that meets the preferred 1.5-inch length. However, hair from several head or body locations can be combined to obtain a sufficient amount of hair for testing.

Free Download: An In-Depth Look at Drug Hair Testing

The hair on your head grows at a predictable rate. A sample of hair that begins at the scalp and extends for 1.5 inches is generally considered to indicate a 90-day window of drug usage, or 30 days for each 1/2 inch of hair. However, the rate of growth of body hair is variable. Thus, if body hair is used for a hair drug test, the results may only be used to indicate a positive or negative result without reference to a specific time frame.

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Written by John Hawes

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John Hawes is the CCO and co-founder at SureHire Occupational Health Testing. John graduated in 2001 from the University of Alberta with a Bachelor of Science degree in physical therapy. As a former physical therapist, John uses his knowledge of physical therapy and interest in ergonomics and biomechanics to devise fit for work testing.

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