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Welcome to Warning Letter Wednesday®

A weekly exploration of FDA warning letters and enforcement trends

Every Wednesday Asa reviews interesting warning letters and other enforcement trends. He’s been writing this each week for 5 years, and it is a labor of regulatory love.

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Current Post July 1, 2026
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Dietary Supplement GMP Lessons

Manufacturing equipment flaws, theoretical yields, incomplete 483 responses, oh my

The warning letter covers manufacturing equipment flaws, theoretical yields, incomplete 483 responses, missing product specifications, and other issues. Fun reminders of the importance of GMP compliance. First, the manufacturing equipment flaws. Here, FDA notes that the seams inside a hopper were not smooth, creating an ...

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Asa Waldstien the author of Warning letter Wednesday

Who is Asa Waldstein?

Asa Waldstein is a 24-year veteran of the dietary supplement industry, with experience spanning manufacturing, marketing, and regulatory compliance. He is the principal of Apex Compliance, a software company dedicated to streamlining regulatory marketing compliance for the dietary supplement and natural products sectors. Asa also leads Supplement Advisory Group, a boutique consultancy focused on marketing risk analysis, labeling, and practical compliance strategies for websites and social media. Asa has helped oversee three FDA GMP inspections with no 483s and was honored with the 2023 AHPA Herbal Hero Award and the 2024 What's Up Supps Policy and Change Agent Award. He currently serves as Chair of the American Herbal Products Association’s (AHPA) Technology & AI Innovation Committee.

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