WARNING LETTER
Imu-Tek Animal Health, Incorporated
MARCS-CMS 724610 —
June 05, 2026
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 defined in section 503(b)(1)(A) of the Act [21 U.S.C. 353(b)(1)(A)], can only be used safely at the direction, and under the supervision, of a licensed practitioner.
Your products Colostrom-5 Capsules and Colostrom-5 Powder are intended for treatment or prevention of one or more diseases that are not amenable to self-diagnosis, treatment, or prevention without the supervision of a licensed practitioner. Therefore, it is impossible to write adequate directions for a layperson to use your products safely for their intended purposes. Accordingly, Colostrom-5 Capsules and Colostrom-5 Powder fail to bear adequate directions for their intended use and, therefore, the products are misbranded under section 502(f)(1) of the Act [21 U.S.C. 352(f)(1)]. The introduction or delivery for introduction into interstate commerce of these misbranded drugs violates section 301(a) of the Act [21 U.S.C. 331(a)].
Adulterated Dietary Supplements
The inspection of your facility from October 6 through October 14, 2025, identified serious violations of the FDA’s regulations for Current Good Manufacturing Practice (CGMP) in Manufacturing, Packaging, Labeling, or Holding Operations for Dietary Supplements, under Title 21, Code of Federal Regulations (CFR), Part 111 (21 CFR Part 111). Thus, in addition to being unapproved new drugs and misbranded drugs, your Colostrum-5 Capsules and Colostrum-5 Powder are also adulterated dietary supplements under section 402(g)(1) of the Act [21 U.S.C. 342(g)(1)] because they have been prepared, packed, or held under conditions that do not meet CGMP requirements for dietary supplements.
Your significant violations of the CGMP requirements are as follows:
1. Your quality control personnel failed to reject a component or dietary supplement or approve a treatment, in-process adjustment, or reprocessing when a deviation or unanticipated occurrence took place during the production and in-process control system that resulted in, or could lead to adulteration of, a component or dietary supplement, as required by 21 CFR 111.113(b)(1). Specifically, your pasteurization procedure for colostrum used in your Colostrum-5 Capsules and Colostrum-5 Powder specifies a time/temperature requirement of
(b)(4)
°F for
(b)(4)
minutes. However, review of multiple Batch Production Records (BPRs) revealed deviations from this procedure. For example, BPR for batch
(b)(4)
documented pasteurization temperatures ranging from
(b)(4)
°F to
(b)(4)
°F, with unspecified hold times. Despite the deviation, you used the colostrum in your Colostrum-5 Capsules and Colostrum-5 Powder without approving a treatment, in-process adjustment, or reprocessing.
In your response dated October 29, 2025, you stated that the pasteurization
(b)(4)
records the proper temperature of the actual pasteurization process. We are unable to evaluate the sufficiency of your correction action because your response does not, for example, explain the basis on which you did not reject product that deviated from your time/temperature requirement for colostrum or the basis on which such deviation was accepted.
2. You failed to establish, for each component that you use in the manufacture of a dietary supplement, identity specifications; component specifications that are necessary to ensure that specifications for purity, strength, and composition of the dietary supplement using the components are met; and component specifications regarding limits on those type of contamination that may adulterate or may lead to adulteration of the finished batch of dietary supplement to ensure the quality of the dietary supplement, as required by 21 CFR 111.70(b). Specifically, you stated that the firm has not established any raw material specifications for any of the components used in the dietary supplements you produce.
In your response dated October 29, 2025, you provided a list of tests that your firm performs and stated that you are in the process of creating a composition baseline with
(b)(4)
. We are unable to evaluate the sufficiency of your corrective actions because you did not provide documentation of established component specifications.
In addition to establishing the required specifications, your firm must determine whether such specifications are met, in accordance with 21 CFR 111.73 and 111.75.
3. You did not establish product specifications for the identity, purity, strength, composition of the finished batch of the dietary supplement, and for limits on those types of contamination that may adulterate, or that may lead to adulteration of, the finished batch of the dietary supplement to ensure the quality of the dietary supplement, as required by 21 CFR 111.70(e). Specifically, during the inspection you stated that you have not established finished product specifications for any of your dietary supplements.
In your response dated October 29, 2025, you stated that the “range or limits were not evident on the testing form. However, the limits are recorded in our file of dietary supplement requirements,” and your new format will be submitted when finished. We are unable to evaluate the sufficiency of your corrective action because you have not provided specifications for your finished products that demonstrate the requirements in 21 CFR 111.70(e) have been met.
In addition to establishing the required specifications, your firm must determine whether such specifications are met, in accordance with 21 CFR 111.73 and 111.75.
4. You failed to prepare and follow a written master manufacturing record (MMR) for each unique formulation of dietary supplement that you manufacture, and for each batch size, to ensure uniformity in the finished batch from batch to batch, as required by 21 CFR 111.205(a). Specifically, during the inspection the investigator requested your MMRs for Colostrum-5 Capsules and Colostrum-5 Powder, and you stated that you did not have an MMR.
You must have a written MMR for each dietary supplement you manufacture that includes the following:
The name of the dietary supplement to be manufactured and the strength, concentration, weight, or measure of each dietary ingredient for each batch size [21 CFR 111.210(a)];
A complete list of components to be used [21 CFR 111.210(b)];
An accurate statement of the weight or measure of each component to be used [21 CFR 111.210(c)];
The identity and weight or measure of each dietary ingredient that will be declared on the Supplement Facts label and the identity of each ingredient that will be declared on the ingredients list of the dietary supplement [21 CFR 111.210(d)];
A statement of any intentional overage amount of a dietary ingredient [21 CFR 111.210(e)];
A statement of theoretical yield of a manufactured dietary supplement expected at each point, step, or stage of the manufacturing process where control is needed to ensure the quality of the dietary supplement, and the expected yield when you finish manufacturing the dietary supplement, including the maximum and minimum percentages of theoretical yield beyond which a deviation investigation of a batch is necessary and material review is conducted and disposition decision is made [21 CFR 111.210(f)];
A description of packaging and a representative label, or a cross-reference to the physical location of the actual or representative label [21 CFR 111.210(g)];
Written instructions, including the following:
o Specifications for each point, step, or stage in the manufacturing process where control is necessary to ensure the quality of the dietary supplement and that the dietary supplement is packaged and labeled as specified in the MMR [21 CFR 111.210(h)(1)];
o Procedures for sampling and a cross-reference to procedures for tests or examinations [21 CFR 111.210(h)(2)];
o Specific actions necessary to perform and verify points, steps, or stages in the manufacturing process where control is necessary to ensure the quality of the dietary supplement and that the dietary supplement is packaged and labeled as specified in the MMR [21 CFR 111.210(h)(3)];
 Such specific actions must include verifying the weight or measure of any component and verifying the addition of any component [21 CFR 111.210(h)(3)(i)]; and
 For manual operations, such specific actions must include:
One person weighing or measuring a component and another person verifying the weight or measure [21 CFR 111.210(h)(3)(ii)(A)]; and
One person adding the component and another person verifying the addition [21 CFR 111.210(h)(3)(ii)(B)];
o Special notations and precautions to be followed [21 CFR 111.210(h)(4)];
o Corrective action plans for use when a specification is not met [21 CFR 111.210(h)(5)].
We have reviewed your response to the FDA Form 483, dated October 29, 2025, which states that your “capsule” bottling form “should cover the issues” relating to the requirement to establish an MMR. We are unable to evaluate the sufficiency of your corrective action because the documentation you provided does not contain all required information required in an MMR.
5. You failed to include necessary information in the batch production records (BPRs), as required in 21 CFR 111.260. Specifically, your “Colostrum
(b)(4)
Reports,” which you provided as your BPRs for your Colostrum-5 Capsules and your Colostrum-5 Powder, are missing the following required information:
The unique identifier that you assigned to each component (or, when applicable, to a product that you receive from a supplier for packaging or labeling as a dietary supplement), packaging, and label used [21 CFR 111.260(d)];
The identity and weight or measure of each component used [21 CFR 111.260(e)]. For example, your BPR indicates that silica is a component in the final capsule product, but the BPR does not document how much silica was added.
The results of any testing or examination performed during the batch production, or a cross-reference to such results [21 CFR 111.260(h)];
Documentation that the finished dietary supplement meets specifications established in accordance with 21 CFR 111.70(e) and (g) [21 CFR 111.260(i)];
Documentation, at the time of performance, of packaging and labeling operations, including the unique identifier that you assigned to packaging and labels used; an actual representative label, or cross-reference to a physical location of the actual or representative label specified in the MMR; and the results of any tests or examinations conducted on packaged and labeled dietary supplements (including repackaged or relabeled dietary supplements), or a cross-reference to the physical location of such results [21 CFR 111.260(k)];
Documentation at the time of performance that quality control personnel approved or rejected the batch for distribution [21 CFR 111.260(l)(3)].
In your response dated October 29, 2025, you provided a blank excel template for your Colostrum-5 Capsules that includes dates/times for mixing, a calculation for final product yields, and a review and approval section. We are unable to evaluate the sufficiency of your corrective action because the documentation you provided does not include all information required by 21 CFR 111.260.
This letter is not intended to be an all-inclusive statement of violations that may exist in connection with your products. You are responsible for investigating and determining the causes of any violations and for preventing their recurrence or the occurrence of other violations. It is your responsibility to ensure that your firm complies with all requirements of federal law, including FDA regulations.
This letter notifies you of our concerns and provides you an opportunity to address them. Failure to adequately address this matter may result in legal action including, without limitation, seizure and injunction.
Please notify FDA in writing, within 15 working days of receipt of this letter, of the specific steps you have taken to address any violations. Include an explanation of each step being taken to prevent the recurrence of violations, as well as copies of related documentation. If you cannot complete corrective actions within 15 working days, state the reason for the delay and the time within which you will do so. If you believe that your products are not in violation of the Act, include your reasoning and any supporting information for our consideration.
Your written reply should be directed to Lauren Crivellone, United States Food and Drug Administration, Human Foods Program, Office of Enforcement, 5001 Campus Drive, College Park, Maryland 20740-3835 or via email at HFP-OCE-DietarySupplements@fda.hhs.gov. Please reference CMS # 724610 on any submissions and within the subject line of any emails to us. If you have any questions, you may email Ms. Crivellone at HFP-OCE-DietarySupplements@fda.hhs.gov.
Sincerely,
/S/
Maria S. Knirk, JD, MBA
Director, Office of Enforcement
Office of Compliance and Enforcement
Human Foods Program
Content current as of:
06/23/2026
Regulated Product(s)
Drugs
Food & Beverages