Unapproved New Drugs: FDA Warning Letter to Bioactive Services USA, LLC / Herstat Inc., 2026-10-01
Letter issued · posted to fda.gov .
Subject as published: Unapproved New Drugs
TL;DR
Here's the summary: On October 1, 2026, the FDA's Center for Drug Evaluation and Research issued a warning letter to Bioactive Services USA, LLC / Herstat Inc. (CEO Kevin Aspinall Nessling) citing violations related to the marketing of "Herstat GST" as an unapproved new drug. The product, marketed on websites https://drsosnowski.com/ and https://www.herstat.com/ for treatment of genital sores, lacks FDA approval required under section 505(a) of the FD&C Act and is not generally recognized as safe and effective (GRASE); the FDA noted that no over-the-counter drug product for treatment of sexually transmitted infections has been approved, and unapproved products for STI treatment present serious public health risks including potential for individuals to forgo appropriate medical care.
Argus analysis
# FDA Warning Letter Analysis: Bioactive Services USA, LLC / Herstat Inc.
The FDA's Center for Drug Evaluation and Research (CDER) issued a warning letter to Bioactive Services USA, LLC and Herstat Inc. on October 1, 2026, citing the unapproved marketing of "Herstat GST," a product sold for genital sore treatment. The letter, addressed to CEO Kevin Aspinall Nessling, followed an agency review of the company's websites (drsosnowski.com and herstat.com) and associated social media accounts in July 2026. The FDA identified the product as an unapproved new drug being sold directly to consumers for treatment of sexually transmitted infections and related symptoms—a classification that triggered significant public health concerns around consumers forgoing professional medical care.
The violations center on sections 201(g)(1), 201(p), 301(d), and 505(a) of the Federal Food, Drug, and Cosmetic Act and their implementing regulations in 21 CFR 201.128. Under these citations, any product intended to treat, cure, or mitigate disease constitutes a "drug" requiring FDA approval before marketing. The agency determined that Herstat GST's labeling claims—including "rapid and targeted relief" and "effective treatment" language—establish drug intent without an approved New Drug Application. The product also exceeds permitted indications under the OTC External Analgesic Monograph (M017), which does not authorize STI treatment claims.
The company had fifteen business days from letter receipt to submit a written response detailing corrective actions and root cause analysis to FDAAdvisory@fda.gov (reference 734784). Compliance officers in OTC drug marketing should monitor whether Bioactive Services removes product claims, withdraws the product from commerce, or pursues formal approval pathways. The FDA explicitly warned that failure to address violations may result in seizure or injunction proceedings without further notice.
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
Unapproved-drug letters cite 21 USC 355 (NDA requirement) or 21 USC 331(d) (introduction into interstate commerce). FDA increasingly applies these provisions to homeopathic products, kratom, and certain compounded preparations.
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 Bioactive Services USA, LLC / Herstat Inc. MARCS-CMS 734784 — October 01, 2026 More Warning Letters Warning Letters About Warning and Close-Out Letters Delivery Method: VIA ELECTRONIC MAIL READ/DELIVERY RECEIPT REQUESTED Product: Drugs Over-the-Counter Drugs Recipient: Recipient Name Kevin Aspinall Nessling Recipient Title CEO Bioactive Services USA, LLC / Herstat Inc. 1309 Coffeen Ave, STE 1200 Sheridan , WY 82801 United States contact@herstat.com Issuing Office: Center for Drug Evaluation and Research (CDER) United States October 1, 2026 Herstat (USA) Inc. 680 S Cache Street Suite 100 – 10219 Jackson, WY 83001 United States WARNING LETTER Reference Number: 734784 To Kevin Aspinall Nessling: This warning letter advises you of significant violations observed during a U.S. Food and Drug Administration (FDA) review of your websites, https://drsosnowski.com/ and https://www.herstat.com/, and provides you an opportunity to address them. Promptly address any violations described herein without delay, including ensuring that appropriate resources are allocated to fully address them and prevent their recurrence. This is not intended to be an all-inclusive list of the violations that may exist in connection with your products or operations. It is your responsibility to ensure that your firm complies with all requirements of federal law, including FDA regulations. Failure to adequately address violations may result in regulatory or legal action without further notice including, without limitation, seizure and injunction. As discussed below, the “Herstat GST” product on your website is an unapproved new drug. Unapproved drug products marketed for the treatment of sexually transmitted infections (STIs) and/or their symptoms and sold directly to consumers present a serious public health concern. Individuals who rely on these products may forgo timely, appropriate medical care, increasing their risk of severe complications such as infertility, sepsis, and death. Further, a false sense of having been adequately treated may lead individuals to unknowingly transmit infections to their partners. FDA has not approved any over-the-counter (OTC) drug product for the treatment, cure, mitigation, or prevention of any STI. Effective treatment requires diagnosis and supervision by a licensed healthcare professional. FDA Review Violations were identified and documented during a review of your websites, https://drsosnowski.com/ and https://www.herstat.com/ in July 2026. We have also reviewed your Facebook and Instagram accounts at https://www.facebook.com/DoctorSosnowski and https://www.instagram.com/drsosnowskis/ where you direct consumers to your website to purchase your products. Based on our review, “Herstat GST” is an unapproved new drug under section 505(a) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), 21 U.S.C. 355(a). As explained further below, introducing or delivering these products for introduction into interstate commerce violates sec…
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
- 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 Unapproved drug warning letter?
- Unapproved-drug letters cite 21 USC 355 (NDA requirement) or 21 USC 331(d) (introduction into interstate commerce). FDA increasingly applies these provisions to homeopathic products, kratom, and certain compounded preparations.
- What is the standard FDA response window for a warning letter?
- FDA warning letters typically require a written response within 15 working days of receipt, outlining the corrective and preventive actions the company will take.
- Has Bioactive Services USA, LLC / Herstat Inc. had FDA enforcement actions before?
- This is the only FDA Warning Letter Argus HQ has on file for Bioactive Services USA, LLC / Herstat Inc. as of 2026-10-06. Argus ingests new FDA enforcement records daily.
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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). Unapproved New Drugs: FDA Warning Letter to Bioactive Services USA, LLC / Herstat Inc., 2026-10-01. Digital Empire Holdings LLC. Retrieved from https://argushq.ai/fda/warning-letter/fda-wl-bioactive-services-usa-llc-herstat-inc-2026-10-01-unapproved-drug
"Unapproved New Drugs: FDA Warning Letter to Bioactive Services USA, LLC / Herstat Inc., 2026-10-01." Argus HQ Research, Digital Empire Holdings LLC, 2026, argushq.ai/fda/warning-letter/fda-wl-bioactive-services-usa-llc-herstat-inc-2026-10-01-unapproved-drug.
Argus HQ Research. "Unapproved New Drugs: FDA Warning Letter to Bioactive Services USA, LLC / Herstat Inc., 2026-10-01." Digital Empire Holdings LLC. Accessed October 8, 2026. https://argushq.ai/fda/warning-letter/fda-wl-bioactive-services-usa-llc-herstat-inc-2026-10-01-unapproved-drug.
@misc{argushq_argushq_ai_fda_warning_letter_fda_wl_bioactive_services_usa_llc_herstat_inc_2026_10_01_unapproved_drug_2026,
title = {Unapproved New Drugs: FDA Warning Letter to Bioactive Services USA, LLC / Herstat Inc., 2026-10-01},
author = {{Argus HQ Research}},
year = {2026},
publisher = {Digital Empire Holdings LLC},
url = {https://argushq.ai/fda/warning-letter/fda-wl-bioactive-services-usa-llc-herstat-inc-2026-10-01-unapproved-drug},
note = {Accessed: October 8, 2026}
}