The PharmChek® Sweat Patch at a Glance

The FDA-cleared PharmChek® Drugs of Abuse Sweat Patch is a proven and economical alternative to urinalysis and provides distinct advantages:

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

Extended Testing Windows

With conventional urine tests, the window of detection is narrow, typically only one to three days. The PharmChek® Sweat Patch provides up to 7 to 10 days of continuous detection per patch, even longer when paired with our optional PharmChek® Overlay. This extended window of detection provides a more comprehensive picture of behavior that supports recovery and helps prevent relapse.

Noninvasive Testing and Collection

Testing with the Sweat Patch maintains privacy and does not require invasive sample collections. No observation of sample collection is necessary, and sample collection is fast and unobtrusive.

Better Accuracy

Courts have relied on the FDA’s clearance of the PharmChek® Sweat Patch as proof of its reliability. In fact, dozens of peer-reviewed academic studies support the accuracy of the Sweat Patch, with hundreds of court rulings to back up its reputation for forensically dependable results.

With a SAMHSA Certified lab, quality control for specimen screening and confirmation testing is incredibly strict. Each Sweat Patch that screens positive is automatically advanced to confirmation testing via LC/MS/MS. The screening and confirmation results are then sent promptly to the supervising authority through a password-protected web portal or via FAX.

Another benefit over urine tests is that PharmChek® is gender indifferent. Same-gender observation is not required, so male officers can apply PharmChek® to female clients, and vice versa. Drugs of abuse metabolize at different rates in males and females, often creating more difficulty in detecting drug use if gender is not considered in the testing and screening process. With the 24-7 continuous collection of both parent drugs and metabolites, Sweat Patch results are equally accurate, regardless of gender.


The polyurethane membrane that covers the collection patch provides a tamper-evident protective layer. And with trained observers for application and removal, the signs of an attempted removal or substitution are obvious. In fact, it’s nearly impossible to substitute a valid sample with a donor sample without clear evidence of deception.

But even more important, typical methods to alter test results are not effective with the sweat collection method of PharmChek® Sweat Patches. Diluting the sample with excessive water consumption does not work, and the parent drug and metabolites cannot be covered up by consuming other foods or drinks.

Excellent for Motivational Enhancement Therapy

As a basis for both reward and sanction, the Sweat Patch offers a strong indicator of continued sobriety. In court rulings that require parole terms, parental rights, or recovery mandates, the PharmChek® Sweat Patch can stand as a positive reinforcement for motivational enhancement therapy and contingency management.

Likewise, with its longer sampling period, the Sweat Patch offers a better view into use patterns over time in order to revise treatment and recovery plans for substance use concerns, as well as offering a more dependable data point for court sanctions when necessary.

Less Expensive than Urine 5 Tests

Although a single patch may cost more than a single 5-panel urine lab test, the PharmChek® Sweat Patch provides a less expensive testing method when multiple urine tests would be required. The same level of detection via urine tests may take as many as four to five urine tests per week, tipping the cost scales in favor of the single Sweat Patch for up to 7 to 10 days of detection. And with only a single appointment for application and one more for collection, wearers face less travel time and fewer time constraints to remain court-compliant. Learn more about PharmChek® on our resources page, or become a trained observer through our online training modules and certification.

The Bottom Line

The PharmChek® Sweat Patch is both a deterrent to drug use and is less expensive to use compared to urinalysis.

Better. Cleaner. Smarter.

FDA-cleared and trusted for over three decades by our nation's criminal justice system, the PharmChek® Sweat Patch is your better, cleaner, smarter option to detect drugs of abuse.