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Sweat Patch

The PharmChek® Sweat Patch captures insensible perspiration, the uncontrolled loss of sweat from the skin, in an absorbent pad. Approximately 300–700 ml of insensible sweat is excreted each day, and about 2ml is absorbed in the patch each week.  The polyurethane film is a semi-permeable membrane that allows small molecules, such as oxygen, carbon dioxide, and water vapor to pass through the patch— leaving the skin underneath healthy and sterile.  Substances of large molecular weight are trapped in the absorbent pad and submitted to the laboratory for analysis by LC/MS/MS. The patch is used to test for drugs of abuse.

Sweat Patch Benefits

Detects the drug metabolite and parent drug—The lab deploys a reporting requirement that the parent drug in each instance (Methamphetamine or Cocaine) must be at or above the cutoff level of 10 ng/mL, and the respective metabolites (amphetamine or BE) must also be present at the LOQ, (Limit of Quantitation) at 2.0 ng/ml or higher. When these two reporting criteria are met it proves ingestion rather than environmental contamination.

Difficult to dilute, substitute, or adulterate without detection

24/7 continuous wear time (7 to 10 days per patch)

Used as a reward or sanction


Gender indifferent

Provides an extended window of detection (beginning 24-48 hours prior to its application and throughout the wear-time of the patch)



The Sweat Patch is a collection device designed to retain evidence of drug use for an extended period of time.


Patch worn for 7 days at a time.

Detect drug use 24 - 48 hours before the application of the patch, during the wear period and up to 24 hours prior to removal.

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