Hair analysis

Hair analysis is the testing of hair taken from the scalp for levels of different minerals. It purports that this information will show the diseases the subject has or will get. It is widely and aggressively marketed. These analyses are paid for out-of-pocket. Chelation therapy, colonic hydrotherapy, or other costly "detoxifying" treatments are often offered as a follow-up to "cure" the problems found in the hair. Like most pseudosciences, evidence for hair analysis relies on "testimonials" of individuals rather than correctly done scientific studies.

Quackwatch reported that one sample they sent in to be tested was returned with a list of 23 "possible or probable conditions", and 56 supplement doses were recommended. Most studies indicate that there is no reliability in hair analysis.

Why hair analysis does not work

 * Levels of minerals in the hair do not correlate with levels in the body.
 * Laboratory techniques are inconsistent &mdash; the same hair analyzed in different labs shows different readings.
 * There are no known "normal" ranges for minerals in hair, so the numbers given by the lab are nonsensical.
 * Hair analysis is affected by color, texture, age, environmental exposure, and other factors, rendering results invalid.
 * Most importantly, hair analysis has never been proven to help diagnose or treat any disease.

Hair analysis that works
Hair analysis actually does help detect arsenic levels… usually in dead bodies.

Hair analysis drug testing
Analysis of the hair does provide forensic evidence of drug use. Trace amounts of the target drug or drug metabolite are deposited in hair follicles and entrapped in hair shaft's core as it grows out from the hair follicle. As hair grows at a rate of about half an inch per month, if the hair is long enough, it can provide an accurate historical record of when drug use took place and approximately how often the drug is taken (once or twice a week, daily or constantly). Since target drug or drug metabolite residues are chemically and structurally stable for a while, they cannot be easily washed, bleached, or flushed out of the hair structure. Gas chromatography/mass spectrometry laboratory analysis of the hair shaft from an individual can achieve highly accurate drug test results and provide a historical use record. Generally, it takes approximately 5 days for drugs to show up in a person's hair and will continue to be detectable in new hair growth for several months. Fingernails can also be analyzed to indicate drug use 4 or 5 months previously.