2026-06-05 FDA Warning Letter: Imu-Tek Animal Health, Incorporated Cited for Dietary Supplement/New Drug/Misbranded
Letter issued · posted to fda.gov .
Subject as published: Dietary Supplement/New Drug/Misbranded
TL;DR
The short version: FDA's Human Foods Program issued a Warning Letter to Imu-Tek Animal Health, Incorporated on 2026-06-05 regarding Dietary Supplement/New Drug/Misbranded. The letter references 21 CFR 201.5. The verbatim letter is published on fda.gov.
Argus analysis
Imu-Tek Animal Health, Incorporated received a Warning Letter from FDA's Human Foods Program, dated 2026-06-05, regarding Dietary Supplement/New Drug/Misbranded. The letter follows an FDA inspection and is classified by Argus HQ as critical severity, consistent with dietary supplement violations.
The published letter cites 21 CFR 201.5. Warning Letters citing these sections generally concern dietary supplement violations, typically 21 USC 343(r)(6) (unauthorized structure-function claims) or 21 CFR Part 111 (supplement CGMP). The full citation language and supporting observations are in the verbatim letter linked below — Argus HQ does not add citations beyond what FDA published.
FDA Warning Letters carry a 15-business-day response window for the recipient to detail corrective actions. Peer compliance teams in the same product category typically use a letter like this one as an external audit trigger, checking whether their own quality system has documented coverage for the cited sections and whether their CAPA log would withstand the same line of inspection questioning.
Severity context
Critical severity. Typically reserved for data integrity, sterile-product CGMP, or repeat violations — matters that historically precede injunctions, consent decrees, or import alerts.
Regulatory background
Dietary supplement Warning Letters typically cite 21 USC 343(r)(6) (structure-function claims), 21 USC 321(g) (drug-vs-supplement classification), or 21 CFR Part 111 (CGMP for supplements). DSHEA-era boundaries are the recurring theme.
What peer compliance teams typically do next
Most compliance officers at peer companies use a Warning Letter against a named entity as a checklist for their own CAPA program. Common steps: pull the verbatim FDA letter; map each cited 21 CFR section against the team’s SOP library; confirm CAPA coverage; brief the QMR (Quality Management Review) on whether the cited subject matter is in scope for the next internal audit. The 15-business-day response window applies to the cited entity, not to peers — but a documented internal review against the cited subjects is what regulators expect to see if a peer is later inspected on the same topic.
Excerpt from the FDA Warning Letter (public domain, 17 USC §105)
WARNING LETTER Imu-Tek Animal Health, Incorporated MARCS-CMS 724610 — June 05, 2026 More Warning Letters Warning Letters About Warning and Close-Out Letters Delivery Method: Via Email Product: Drugs Food & Beverages Recipient: Recipient Name Henry S. Dyjak, President/Co-Owner Recipient Title Susan A. Dyjak, Vice President/Co-Owner Imu-Tek Animal Health, Incorporated 3541 E. Vine Dr. Fort Collins , CO 80524 United States Henryd@Imutek.com Issuing Office: Human Foods Program United States June 5, 2026 WARNING LETTER CMS # 724610 Dear Mr. and Mrs. Dyjak: The U.S. Food and Drug Administration (FDA) conducted an inspection of your facility located at 3541 E. Vine Dr., Fort Collins, CO 80524 from October 6 through October 14, 2025. Based on inspectional findings and our review of your website, www.Imutek.com, we have identified significant violations of the Federal Food, Drug, and Cosmetic Act (the Act) and applicable regulations. You can find the Act and FDA regulations through links on FDA's home page at www.fda.gov. At the conclusion of the inspection on October 14, 2025, our investigator provided you with a Form FDA 483, Inspectional Observations (FDA 483). We acknowledge receipt of your response dated October 29, 2025. Unapproved New Drugs FDA reviewed your website at the Internet address www.imutek.com in April 2026 and has determined that you take orders there for the products Colostrom-5 Capsules and Colostrom-5 Powder. The claims on your website establish that these products are drugs under section 201(g)(1)(B) of the Act [21 U.S.C. 321(g)(1)(B)] because they are intended for use in the cure, mitigation, treatment, or prevention of disease. As explained further below, introducing or delivering these products for introduction into interstate commerce for such uses violates the Act. An example that provides evidence that your products are intended for use as drugs include: “ImuTek Colostrum-5 Capsules and Powder. . . . has been shown to kill bacteria and viral invaders. It can also help correct bowel dysfunction by stimulating tissue repair.” Your products are not generally recognized as safe and effective for the above referenced uses and, therefore, the products are “new drugs” under section 201(p) of the Act [21 U.S.C. 321(p)]. With certain exceptions not applicable here, new drugs may not be legally introduced or delivered for introduction into interstate commerce without prior approval from FDA, as described in sections 301(d) and 505(a) of the Act [21 U.S.C. 331(d), 355(a)]. FDA approves a new drug on the basis of scientific data and information demonstrating that the drug is safe and effective. Misbranded Drugs A drug is misbranded under section 502(f)(1) of the Act [21 U.S.C. 352(f)(1)] if the drug fails to bear adequate directions for its intended use(s). “Adequate directions for use” means directions under which a layperson can use a drug safely and for the purposes for which it is intended (21 CFR 201.5). Prescription drugs, as define…
Excerpt only. The full verbatim Warning Letter is the source of truth — always read the original before regulatory decisions.
The verbatim FDA Warning Letter is the source of truth. Always read the original before acting on any analysis or summary on this page.
Read the full letter on fda.gov ↗Frequently asked questions
- When did FDA issue the warning letter to Imu-Tek Animal Health, Incorporated?
- FDA issued the letter (MARCS-CMS 724610) on 2026-06-05 and posted it publicly on fda.gov on 2026-06-23.
- Is the FDA warning letter to Imu-Tek Animal Health, Incorporated publicly available?
- Yes. The full verbatim letter is published at fda.gov. Argus HQ links directly to the source: https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/imu-tek-animal-health-incorporated-724610-06052026.
- What does a "critical" severity rating mean for this letter?
- Critical severity. Typically reserved for data integrity, sterile-product CGMP, or repeat violations — matters that historically precede injunctions, consent decrees, or import alerts.
- What is the regulatory background for a Dietary supplement warning letter?
- Dietary supplement Warning Letters typically cite 21 USC 343(r)(6) (structure-function claims), 21 USC 321(g) (drug-vs-supplement classification), or 21 CFR Part 111 (CGMP for supplements). DSHEA-era boundaries are the recurring theme.
argus.hq
Don’t find out about the next one six weeks late.
Argus reads every FDA Warning Letter the day it publishes, summarizes it against your watchlist, and lands the ones touching your business in your inbox at 6am ET. $199/month. Cancel any time.
methodology
The analysis above is produced by Anthropic Claude Haiku 4.5 against the verbatim FDA Warning Letter excerpt and is brand-voice lint-checked before publish. The TL;DR is the same summary that ships in the customer email digest. Severity is auto-classified by Argus from the subject string and letter body using rules documented in lib/ingestion/fda-warning-letters.ts.
Argus HQ is informational only. Summaries and analyses are AI-generated and may contain errors, misclassifications, or omissions. Verify against the FDA source URL above. Argus HQ is not a law firm, accounting firm, or regulatory agency, and provides no legal, accounting, financial, medical, or regulatory advice.
Compiled by Argus HQ Research from FDA primary sources · Reviewed by Andy Gaber, Founder
Cite this record
Reusing this data in reporting or research? Here’s a ready-made citation.
Argus HQ Research (2026). 2026-06-05 FDA Warning Letter: Imu-Tek Animal Health, Incorporated Cited for Dietary Supplement/New Drug/Misbranded. Digital Empire LLC. Retrieved from https://argushq.ai/fda/warning-letter/fda-wl-imu-tek-animal-health-incorporated-2026-06-05-dietary-supplement
"2026-06-05 FDA Warning Letter: Imu-Tek Animal Health, Incorporated Cited for Dietary Supplement/New Drug/Misbranded." Argus HQ Research, Digital Empire LLC, 2026, argushq.ai/fda/warning-letter/fda-wl-imu-tek-animal-health-incorporated-2026-06-05-dietary-supplement.
Argus HQ Research. "2026-06-05 FDA Warning Letter: Imu-Tek Animal Health, Incorporated Cited for Dietary Supplement/New Drug/Misbranded." Digital Empire LLC. Accessed July 13, 2026. https://argushq.ai/fda/warning-letter/fda-wl-imu-tek-animal-health-incorporated-2026-06-05-dietary-supplement.
@misc{argushq_argushq_ai_fda_warning_letter_fda_wl_imu_tek_animal_health_incorporated_2026_06_05_dietary_supplement_2026,
title = {2026-06-05 FDA Warning Letter: Imu-Tek Animal Health, Incorporated Cited for Dietary Supplement/New Drug/Misbranded},
author = {{Argus HQ Research}},
year = {2026},
publisher = {Digital Empire LLC},
url = {https://argushq.ai/fda/warning-letter/fda-wl-imu-tek-animal-health-incorporated-2026-06-05-dietary-supplement},
note = {Accessed: July 13, 2026}
}