WARNING LETTER
Half Hill Farm Inc.
MARCS-CMS 720213 —
March 06, 2026
Delivery Method:
Via Email
Product:
Drugs
Food & Beverages
Recipient:
Recipient Name
Christian M. Grantham
Recipient Title
Owner
Half Hill Farm Inc.
110 W. High St.
Woodbury
,
TN
37190
United States
Issuing Office:
Human Foods Program
United States
March 6, 2026
WARNING LETTER
CMS # 720213
Dear Mr. Grantham:
The U.S. Food and Drug Administration (FDA) conducted an inspection of your facility located at 110 W. High St., Woodbury, TN 37190 on 05/28/25 to 05/30/25. Based on inspectional findings and review of the product labeling collected during the inspection, as well as review of your website www.halfhillfarm.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 May 30, 2025, our investigator provided you with a Form FDA 483, Inspectional Observations (FDA 483). We acknowledge receipt of your response dated June 13, 2025, and we address your response below.
Unapproved New Drugs
FDA reviewed your website at the Internet address www.halfhillfarm.com in February 2026 and has determined that you take orders there for the products Turkey Tail Mushroom Extract, Chaga Mushroom Extract, and Red Reishi Mushroom Extract. The claims on your website establish that the 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.
Your website includes disease claims in the form of citations to publications or references. When scientific publications or references are used commercially by the seller of a product to promote the product to consumers, such references may become evidence of the product's intended use. For example, under 21 CFR 101.93(g)(2)(iv)(C), a citation of a publication or reference in the labeling of a product is considered to be a claim about disease treatment or prevention if the citation refers to a disease use and if, in the context of the labeling as a whole, the citation implies treatment or prevention of a disease. The following examples of citations on your website https://www.halfhillfarm.com/news-research/ used to market “Turkey Tail Mushroom Extract, Chaga Mushroom Extract, and Red Reishi Mushroom Extract” for disease treatment or prevention are evidence of your products’ intended use as drugs:
Under the Newspaper header:
“Farmers Turn To Cancer-Fighting – Cannon Courier – April 9, 2014”
Under the Research on Turkey Tail (Trametes Versicolor) mushrooms header:
“Turkey Tail mushrooms and our personal fight against cancer – Half Hill Farm – December 6, 2013”
“Complete clinical summary: Turkey Tail – Memorial Sloan Kettering Cancer Center.”
Under the “Research on Chaga (
Inonotus obliquus
) mushrooms” header:
“Ethanol extract of Innotus obliquus (Chaga mushroom) induces G1 cell cycle arrest in HT-29 human colon cancer cells –
Nutrition Research and Practice
– April 2015”
“Liquid extract from a Chaga medicinal mushroom, Inonotus obliquus (higher Basidiomycetes), prevents herpes simplex virus entry through inhibition of viral-induced membrane fusion –
International Journal of Medicinal Mushrooms
– 2013”
Under the “Research on Red Reishi (
Ganoderma lucidum
) mushrooms” header:
“Ganoderma lucidum (Reishi) in cancer treatment – NIH”
“Ganoderma lucidum exerts anti-tumor effects on ovarian cancer cells – International Journal of Oncology – May 2011”
“The Effect of Mushroom Beta-Glucans from Solid Culture of Ganoderma lucidum on Inhibition of the Primary Tumor Metastasis – Evidence-Based Complementary and Alternative Medicine – April 2014”
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 Turkey Tail Mushroom Extract, Chaga Mushroom Extract, and Red Reishi Mushroom Extract 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, your Turkey Tail Mushroom Extract, Chaga Mushroom Extract, and Red Reishi Mushroom Extract products 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)].
We also have the following comment:
We have reviewed your response to the FDA Form 483, dated June 13, 2025, and find it does not adequately address the violation. In your response, you stated that you
(b)(4)
. However, you did not provide documentation to support that those changes to the label have been made.
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 Natalie J. Reese, 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 # 720213 on any submissions and within the subject line of any emails to us. If you have any questions, you may email at HFP-OCE-DietarySupplements@fda.hhs.gov.
Sincerely,
/S/
Maria S. Knirk, JD, MBA
Acting Director, Office of Enforcement
Office of Compliance and Enforcement
Human Foods Program
Content current as of:
04/14/2026
Regulated Product(s)
Drugs
Food & Beverages