FDA WARNING_LETTER - Sinsin Pharmaceutical Co., Ltd. - April 15, 2025

Sinsin Pharmaceutical Co., Ltd. received a warning letter from the FDA on November 12, 2025, following a review conducted on April 15, 2025. The review focused on the company"s product labeling and online marketing for SINSINPAS AREX INSTANT PAIN RELIEF and SINSINPAS Pain Relieving Liquid MULPAS, which are available for purchase in the United States. The FDA identified significant regulatory violations under the Federal Food, Drug, and Cosmetic Act (FD&C Act).

The main issues highlighted include the marketing of these products as unapproved new drugs and their misbranding. According to the FDA, these products are intended for use as external analgesics but do not conform to the conditions specified in the applicable OTC monograph (M017) for over-the-counter human use. Specifically, the active ingredients in these products, such as zinc oxide, mentha oil, chlorpheniramine maleate, and thymol, are not permitted under the monograph when used in combination or as sole ingredients. Consequently, the products are not generally recognized as safe and effective (GRASE) and are considered unapproved new drugs.

The FDA requires Sinsin Pharmaceutical to address these violations by ensuring compliance with federal law and FDA regulations. The company must investigate the causes of these violations, prevent their recurrence, and ensure all products meet legal requirements. Failure to adequately address these issues could result in further regulatory action. The letter serves as a formal notification and an opportunity for the company to rectify the identified concerns.