Hair: Substance abuse can be detected in hair months after substance ingestion date. Trend in drug use or abstinence may also be provided with month-to-month analysis of hair sections.

Nail: Fingernail specimens are obtained by the donor in front of a trained collection staff. When drug and alcohol are ingested, markers can be found in nails 1 to 2 weeks after and may be detected 3 to 6 months after drug or alcohol abuse.