PharmChem Inc, based in Fort Worth, TX, has been the industry leader in sweat-based drug testing for over 30 years with our FDA-cleared product, the PharmChek® Drugs of Abuse Sweat Patch.

PharmChek® has a broad national presence and continues to grow:

  • Used by customers in 48 states and territories.
  • More than 675,000 tests performed in the past five years.
  • Customers include Federal and County Probation, Treatment Courts, Adult Drug Courts, Human Services, and many other agencies and programs.

Worn on the body for up to 7–10 days, the PharmChek® provides 24/7 monitoring for drugs of abuse. Our Sweat Patch technology is tamper-evident, cannot be diluted, substituted, or adulterated without detection, and is confirmed by LC-MS/MS for both parent drug and drug metabolite at our SAMHSA-certified laboratory partner.

The PharmChek® Drugs of Abuse Sweat Patch has a long track record of credibility, starting with the original FDA device clearance in the early 1990s:

  • 1992: FDA clearance of PharmChek device
  • 2004: SAMHSA notes, “Also, scientific advances in the use of head hair, sweat, and oral fluid in detecting drugs have made it possible for these specimens to be used in Federal programs with the same level of confidence that has been applied to the use of urine.” (Federal Register, 4/13/04, 69 FR 19689)
  • 1999: NV court finds Sweat Patch meets Daubert Standard (US v. Stumpf)
  • 2018: PA court finds Sweat Patch satisfies standards of the Frye test (Commonwealth of PA v. Hall)

Today, we join the other courts that have previously determined that sweat patch results are a generally reliable method of determining whether an offender has violated a condition of his or her probation. It is important to note that the Food and Drug Administration cleared the PharmChek® Sweat Patch technology back in 1990. Today, the sweat patch is a widely used method for drug testing that is authorized by the Administrative Office of the United States Courts.

The Honorable Sandra Day O’Connor, Associate Justice of the United States Supreme Court (Ret.), sitting by designation, pursuant to 28 U.S.C. § 294(a). US v. Meyer - 8th Circuit Court of Appeals, 2007

For additional examples of legal precedent supporting the Sweat Patch, visit our Court Cases page.

For additional information on the academic literature supporting sweat-based drug testing, visit our Research Articles page.


PharmChem, Inc. is publicly traded on the OTC/Pink Current under the symbol PCHM. Please visit our Investor Relations page for more details.


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