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# Zyto Illegally Marketing Galvanic Skin Device: FDA
- URL: https://www.fdaweb.com/zyto-illegally-marketing-galvanic-skin-device-fda/
- Published: 2023-07-13T12:00:00.000Z
- Updated: 2026-09-14T18:43:51.000Z
- Author: David McFarland
- Tags: Devices, #legacy-id-D5154871

A 12/5-12/13/2022 FDA inspection at Zyto Technologies in Lindon, UT, determined that the company manufactures the Zyto Hand Cradle Galvanic Skin Response device and associated proprietary software used to scan patients to identify “stressors” and “balancers.” A just-released 6/21 [Warning Letter](https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/zyto-technologies-inc-652316-06212023?ref=fdaweb.com) says some of the “stressors” include diseases and conditions such as Alzheimer’s, HIV, Parkinson’s, and melanoma.

Because the company markets the device and software for indications that are a major change or modification of its intended use, FDA says, the device is adulterated and is being marketed illegally since Zyto does not have an approved PMA application in effect. The device also is misbranded, the letter says, because the company did not notify the agency of its intent to introduce it into commercial distribution.

FDA says the Zyto system (GSR cradle and software) received 510(k) clearance only to measure galvanic skin responses. “Despite prior notice from FDA in your 2015 Warning Letter and some corrections made around that time, your firm has added back promotion of the Zyto hand cradle GSR for use in diagnosing diseases or conditions, including determining whether someone responds to a particular allergen, and continues to predict biological responses to a wide range of virtual stimuli including homeopathic nosodes and nutritional supplements,” the letter says.

The letter also lists specific Quality System Regulation violations:

- failing to adequately establish procedures for design controls;
- failing to adequately establish procedures for corrective and preventive action;
- failing to adequately establish procedures for complaint handling, including an evaluation to determine responsibility, and to document complaint investigations or a record including the reason when no investigation is performed;
- failing to adequately establish a procedure to ensure device history records are maintained to demonstrate the device is manufactured per the device master record; and
- failing to develop, maintain, and implement written labeling procedures to control unique device identifier labeling activities.

Zyto was told to take prompt action to address the violations. “The Zyto hand cradle is adulterated and misbranded and we request that you immediately cease any marketing of this product and its accessories,” FDA says.

The company was told to respond with a list of specific steps it has taken to correct the violations and prevent their recurrence, with documentation of the corrective actions, which must address systemic problems, and a schedule for completing the corrections.