Nail specimens, unlike urine samples, yield information about drug exposure time frames measured in months, rather than days. Drugs can be identified in nail clippings two weeks to four weeks following ingestion. A 3 millimeter specimen of fingernail represents up to eight months of collective history of drug exposure. Urine, on the other hand, for a drug like cocaine, can only yield about three days of prior drug exposure history. Nail testing is available as a 5 or 10 panel.