VITAMINS & SUPPLEMENTS · GUIDE
FDA Warning Letters on Brain Supplements and Unapproved Ingredients: What They Say
What FDA warning letters about "nootropic" and brain products actually say, what a warning letter does and does not mean, and why unapproved-ingredient wording matters.
Content last updated . This page has not been medically reviewed.
Back to NootropicsThis page summarizes warning letters we opened and read on FDA's website. It names no companies and gives no advice on buying anything. FDA publishes many letters; this is a small, hand-picked reading, not a complete list.
What a warning letter is
An FDA warning letter tells a firm that FDA believes it has found violations of the law. In the letter we read most closely, FDA asked for a written reply within fifteen working days [1]. It said the letter was not an all-inclusive statement of violations [1], and that failing to act could lead to enforcement action including seizure or injunction [1]. A letter is FDA's position at a point in time. We did not check how each firm responded, so a letter alone is not a court finding.
Why "unapproved new drug" matters
Several letters use the same reasoning. FDA looks at what a seller claims for a product, such as treating disease or affecting the body's function, and says that makes it a drug [1]. FDA then says products "not generally recognized as safe and effective" for those uses are "new drugs" [1]. It adds that FDA approves a new drug on the basis of scientific data showing it is safe and effective [1].
This links to a common marketing claim. FDA states that it does not approve dietary supplements for safety and effectiveness [2], so wording such as "FDA-approved ingredient" on a supplement deserves a second look. See also Nootropic Safety and Claim Checks.
Letters we read
| Date (FDA, United States) | Type of product | What FDA wrote |
|---|---|---|
| February 4, 2022 | An online seller of several "nootropic" powders and capsules, including noopept | FDA said the claims showed the products were intended as drugs [1], and called them "new drugs" not generally recognized as safe and effective [1]. It noted that a noopept page described the compound as a nootropic similar to racetams [1]. |
| November 10, 2021 | A compounding pharmacy inspection | FDA wrote that drug products compounded using bulk piracetam are not eligible for the exemptions in section 503A(a) [3]. Its stated reasons: piracetam is not in a USP or NF monograph and is not a component of an FDA-approved human drug [3]. |
| November 9, 2021 | A website selling phenibut and other powders | FDA said the website claims established the products were drugs [4]. It quoted a page calling phenibut a "nootropic compound" [4]. |
| May 18, 2021 | A group of websites selling tianeptine and a powder marketed as a nootropic [5] | FDA said tianeptine is used as a prescription drug in some European, Asian, and Latin American countries but is not approved as a drug in the United States [5]. It also said it was aware of several serious adverse event reports associated with tianeptine [5]. |
| July 2, 2024 | Tianeptine products [6] described in marketing as a "proprietary blend" of herbs and nootropics [6] | FDA called them unapproved new drugs in violation of sections 505(a) and 301(d) of the law [6]. |
| February 5, 2026 | Nicotine energy products with "focus" and "ADHD support" claims [7] | FDA said they were unapproved new drugs under section 505(a) [7]. The blog claims it quoted included that nicotine "works similarly to stimulants" [7]. |
What the letters do not show: they do not prove what any product contains, and they do not test whether any ingredient helps memory or focus.
What independent testing has found
A peer-reviewed analysis looked at supplements labeled with four drugs not approved for human use in the United States [8]. Several detected drugs were not declared on the label, and several declared drugs were not detected [8]. The authors concluded that over-the-counter cognitive enhancement supplements may contain multiple unapproved drugs [8]. A 2023 review also noted that what counts as a legal nootropic varies a great deal between countries [9].
Evidence labels and limits
Evidence labels used here: "evidence of harm" and "marketing claim". The letters document marketing claims and regulatory concerns. They are not clinical evidence of benefit or of harm for any single ingredient. Searches of FDA's warning-letter listing for piracetam, noopept, aniracetam, phenylpiracetam, adrafinil and modafinil returned only two letters that named piracetam or noopept; the other letters here came from broader searches for "nootropic". Searches for huperzine and picamilon returned no letters.
Safety and what to do
- Check FDA's public safety pages and Unsafe Products and Warnings for current alerts.
- Tell your clinician or pharmacist about everything you use, including products bought online; see Medication Interactions.
- Pregnancy, breastfeeding, children, kidney or liver conditions and surgery: the letters do not address these, so ask a clinician or pharmacist.
- Suspected poisoning: call 911 or Poison Help at 1-800-222-1222.
Related pages
Racetams, Noopept, Phenibut, Tianeptine and Kratom and How Supplements Are Regulated.
Frequently asked questions
Does an FDA warning letter mean a product is banned?
Not by itself. A letter states FDA's concerns and asks for corrections, and it says failure to act may lead to enforcement such as seizure or injunction [1]. We did not follow up on the outcome of each letter.
Does FDA approve brain supplements?
FDA states that it does not approve dietary supplements for safety and effectiveness [2].
Why does FDA call some supplements "unapproved new drugs"?
Because of the claims. FDA wrote that products claimed to treat disease or affect the body's function, and not generally recognized as safe and effective for those uses, are "new drugs" [1].
Can a supplement contain a drug that is not on the label?
A published analysis found several detected drugs that were not declared on labels, and several declared drugs that were not detected [8]. See Quality Testing and Certifications for how quality testing is described.
Where can I check for current FDA letters?
FDA publishes warning letters on its website. We read the letters cited here on 2026-10-23, and new ones may have been issued since.
References
- FDA warning letter 620285 (Center for Drug Evaluation and Research), February 4, 2022. Read 2026-10-23.
- FDA, Information on Select Dietary Supplement Ingredients and Other Substances, content current as of May 1, 2026. Read 2026-10-23.
- FDA warning letter 615908 (compounding pharmacy inspection), November 10, 2021. Read 2026-10-23.
- FDA warning letter FY22-HAFE6-WL-01 (website sales of a "nootropic compound"), November 9, 2021. Read 2026-10-23.
- FDA warning letter (website sales including a "nootropic" powder), May 18, 2021. Read 2026-10-23.
- FDA warning letter 678912 (tianeptine products described as "nootropics"), July 2, 2024. Read 2026-10-23.
- FDA warning letter 719715 (nicotine products marketed for focus and ADHD support), February 5, 2026. Read 2026-10-23.
- Cohen PA, et al. Five unapproved drugs found in cognitive enhancement supplements. Neurol Clin Pract. 2021 (abstract). Read 2026-10-23.
- Unauthorized ingredients in "nootropic" dietary supplements: a review. Drug Test Anal. 2023 (abstract). Read 2026-10-23.