What are FDA Warning Letters?

If you market dietary supplements, you need to know what the FDA warning letter means and how to avoid it. The U.S. Food and Drug Administration (FDA) issues several types of FDA warning letters when it determines that manufacturer, retailer, or other organization has “significantly violated FDA regulations” (FDA 2011b). The warning letters include three types:

1. General FDA Warning Letters,
2. Tobacco Retail Warning Letters, and
3. Drug Marketing and Advertising Warning Letters (and Untitled Letters to Pharmaceutical Companies).

FDA Warning Letters
The U.S. Food and Drug Administration (FDA) has issued more than 360 warning letters each year, since 2005. Data from the FDA Warning Letters site.


These FDA warning letters go to companies, manufacturers, retailers, individuals, organizations, or groups in the form of a warning letter that identifies a violation or violations. These violations include (FDA 2011b) the following:

1. poor manufacturing practices,
2. problems with claims for what a product can do, or
3. incorrect directions for use.

Aside from describing violations, FDA warning letters dictate what the recipient must do to correct the problem. They also provide instructions and a deadline for informing the FDA of the correction once it has been made.

Warning letters to dietary supplement retailers and others who market dietary supplements often fall under the category of “Drug Marketing and Advertising warning letters (and Untitled Letters to Pharmaceutical Companies) (FDA 2011a), meaning that the violator has somehow described or marketed a dietary supplement as a drug by making “Disease Claims.'” According to the FDA (2011b), “The letters warn these [… marketers …] that they may be engaged in illegal activities and informs them of the laws that govern prescription drug sales.”

FDA Warning Letters for Marketing Misrepresentation and Adulteration

During 2016 alone, 52 firms dealing in dietary supplements received warning letters, and, to date, only one (less than 2% of all firms receiving warning letters), has received a close-out letter from the FDA. Of the 500 warning letters issued to firms since 2005, 304 (60.8%) addressed issues related to the actual quality of the dietary supplements or violations of Current Good Manufacturing Practice (CGMP) regulations enforced by the U.S. FDA. Warnings stated that the dietary supplements were impure, unsafe, unwholesome, or adulterated (FDA 2011a). These ingredients included things like the following:

  • Methylsynephrine, a stimulant drug, known also as oxilofrine, is not considered a dietary supplement by the FDA (2016b).
  • Blackbrush Acacia, or Chaparro Prieto, known previously as Acacia rigidula, has been recently reclassified as Vachellia rigidula. Some vendors have illegally made claims of its properties for weight loss (FDA 2016a).

    Senator Claire McCaskill
    Senator Claire McCaskill, of Missouri, urged the FDA to suspend sales of supplements containing picamilon. Source: Wikimedia.
  • Picamilon, according to the FDA, “does not meet the statutory definition of a dietary ingredient” because, as required by the Federal Food, Drug, and Cosmetic Act (U.S. Congress 2002) it constitutes none of the following:

“a vitamin; mineral; herb or other botanical; amino acid; dietary substance for use by man to supplement the diet by increasing the total dietary intake; or a concentrate, metabolite, constituent, extract, or combination of the preceding substances. In contrast, picamilon is a unique chemical entity synthesized from the dietary ingredients niacin and gamma-aminobutyric acid. Picamilon is absorbed into the body, crosses the blood-brain barrier and accumulates in the brain as a separate chemical entity.”  (FDA 2015c)

  • 7,12-Dimethylbenz[a]anthracene (DMBA), an immunosuppressor and carcinogen may not be used as a dietary supplement, according to the FDA (FDA 2015a).
  • Homeopathic human chorionic gonadotropin (HCG) containing formulas have been the target of  Federal Trade Commission (FTC) and FDA warning letters (2015b) to firms that have labeled them as “homeopathic for weight loss,” in violation of the Federal Food, Drug, and Cosmetic Act and the Federal Trade Commission Act (U.S. Congress 2002).

These are just some of the more common substance marketing items that warranted FDA warning letters. Some 328 of the 500 (65.6%) warning letters issued from 2005 through 2016, to dietary supplement retailers, manufacturers, companies, and individuals applied to cases of mismarketing the supplements, either through misrepresentation, false claims, misleading claims, disease claims, or misinformation. Another 139 (27.8%) of the FDA warning letters went to firms that violated FDA regulations related to both adulteration and mismarketing (FDA 2011a).

FDA Close-Out Letters

The FDA reviews these corrections to determine if the violator has properly mitigated the violation. In the event that …

1. the violator takes corrective actions to mitigate the violations described in the FDA warning letter, and
2. the FDA determines that corrective actions were adequate, …

… the Administration may issue FDA warning letter close-out letter, or, simply, “close-out letter.” It issues such letters only when it has effectively verified that corrections have been implemented. In some cases, it may deem the violations of an uncorrectable nature, and will not issue a close-out letter (FDA 2011b).

Since 2005, the FDA has issued 500 warning letters to firms that deal in dietary supplements. It initiated the practice of issuing close-out letters, by mid-September of 2009, it had issued 436 warning letters since that time. Of these, only 94 of the warning letters (21.5%) received FDA responses in the form of Close-Out Letters. As such, only 21.5% of the dietary supplement firms, in the last decade, have been able to effectively mitigate the FDA charges. The issuance of Close-Out Letters, on average, took 463.2 days (about a year and two months), with the longest issuance time taking 1,673 days, or almost 4.5 years (FDA 2011a).

The FDA takes the mitigatory actions very seriously, and it states that …

“Future FDA inspections and regulatory activities may further assess the adequacy and sustainability of these corrections. Should violations be observed during a subsequent inspection or through other means, enforcement action may be taken without further notice.”


Avoid FDA Warning Letters

When you’re developing marketing material for your dietary supplements, you want to avoid statements that could be a red flag to the FDA and eventually result in an FDA warning letter. Only about one-fifth (21.5%) of firms that receive warning letters eventually receive close-out letters (FDA 2011a), implying that litigation and mitigation of FDA warnings may be costly and complex. Through careful, professional content development, though, you’ll not only avoid a costly FDA warning, but you’ll also have a much more effective and truthful marketing strategy.

GNC Corporation Accused of Mislabelling

Warning letters can result in even very large companies, with large budgets, taking financial hits that hurt their company. A prime example is dietary supplement GNC Corporation. In 2015, the Attorney General’s Office of New York State accused “GNC of selling mislabeled products. … Stock prices for GNC began falling after the New York announcement, with stock prices tumbling a further 43 percent since August 5.” (Gibb 2015)

Dietary supplement giant GNC's stock price took two hits after accusations of mislabeling products during 2015. Chart Source: TradeKing.
Dietary supplement giant GNC’s stock price took two hits after accusations of mislabeling products during August and October of 2015. Chart Source: TradeKing.

Later, Oregon Attorney General Ellen Rosenblum filed a lawsuit against the dietary supplement giant, GNC Corporation. According to the accusation, the company …

“sold dietary supplements that include illegal ingredients. The news sent shares of GNC down about 13% in afternoon trade. Rosenblum said various GNC products contain the synthetic chemical picamilon, or the stimulant BMPEA, both of which are not approved for sale in the U.S.” (Linnane 2015).

Aside from the drop from over $51 a share to less than $27, the cost of litigation, reputation management, and the distraction from daily business has undoubtedly been a burden even to this corporate giant. The stock share price, as of 13 September 2016, has dropped to $20.92. Imagine the damage that a smaller company, business, or sole proprietor would suffer dealing with such accusations.

The FDA expects full compliance to the Federal Food, Drug, and Cosmetic Act (FD&C Act) and Dietary Supplement Health and Education Act of 1994 (DSHEA). As the U.S. Congress has clearly stated in DSHEA (1994), dietary supplement marketers making disease claims certainly violate the law. Be sure to review your existing online or otherwise published content to assure that it complies with FDA criteria, and consult with a content creator or writer familiar with DSHEA compliant text whenever developing new texts or reviewing existing texts.


Literature Cited