NDIs for dietary supplements: How to proceed in 2020

February 24, 2020

The 2011 publication of FDA’s draft guidance on new dietary ingredients (NDIs) caused an uproar in the supplement industry and raised a host of concerns, as previously discussed in this and other publications.1,2 In response to comments received on the 2011 draft guidance, in 2016 FDA issued a revised draft guidance with the aim of more fully answering questions, per their perspective, surrounding the New Dietary Ingredient notification (NDIN) process. The 2016 revised draft guidance greatly overlapped with the topics covered in the 2011 version but was nearly twice as long due to the more detailed explanations provided in the question-and-answer format.

Now, more than three years later, the guidance has not been finalized, and most industry concerns regarding the draft guidance remain. So where are we now in 2020? As we look ahead, it is unclear whether finalization of the guidance is near, and we suspect that challenges surrounding the future regulatory status of hot-topic ingredient hemp cannabidiol (CBD) for use in foods and supplements will further affect FDA’s timeline.

(Editor's note: For further reading about NDI concerns, click here.)


2019, a Year in Review: FDA Meetings on Master Files, Synthetic Ingredients, and More

In the first half of 2019, FDA held private meetings with industry as well as hosted a public meeting on May 16, 2019, to discuss the NDIN process. Comments from the public meeting were heavily skewed to calls for FDA to incentivize industry compliance with the NIDN requirements by enforcing existing regulations and developing a master file program which would allow companies who had invested time and money in the required testing for a successful NDIN submission to protect that investment.

Under a master file system, Company A would submit an NDIN for a dietary ingredient. Company A could then license the use of its safety data to Company B, a company wishing to use the same ingredient from the manufacturing method specified in Company A’s NDIN. Company B might need to do its own studies to expand the application of the NDIN master file for new doses or new combinations of ingredients, but it could rely, at least in part, on data in the NDIN master file. This system would provide for some intellectual property protection for Company A, while enabling multiple companies to take advantage of the same master file.

Other public comments have called on FDA to reconsider its stance on synthetic dietary ingredients. Per the latest draft guidance, FDA only recognizes as dietary ingredients synthetic forms of vitamins and amino acids—and no other synthetic ingredients. The agency does not seem to think that there were any synthetic versions of botanical constituents on the market prior to October 15, 1994—the date delineating NDIs requiring NDINs from “old” dietary ingredients, which do not require NDINs. However, until the agency authorizes a list of “grandfathered” ingredients, it will remain a point of contention whether or not some synthetic ingredients were on the market prior to the cut-off date.

Many speakers at FDA’s May 16, 2019, public meeting also suggested reconsideration of the meaning of “chemically altered” and “manufacturing change” as mentioned in FDA’s draft guidance. The guidance states that ingredients that were previously the subject of a submitted NDIN but that have been chemically altered or altered due to a manufacturing change might require submission of a new NDIN. Due to numerous technological advancements that occurred over the 17 years between passage of the Dietary Supplement Health and Education Act of 1994 (DSHEA) and FDA’s 2011 first attempt at a draft guidance on NDINs, many have questioned whether a change in manufacture should really require a new NDIN—or simply a demonstration of equivalence to a prior NDI. This issue could also be addressed by a master file system.


Where Are We Now? Recent NDIN Activity

Evaluating the current status of the most recent NDIN submissions proves challenging, since FDA’s Submitted 75-Day Premarket Notifications for New Dietary Ingredients webpage3 was lasted updated on May 15, 2019. According to the list of NDINs submitted from 1995 to the present, available as a downloadable spreadsheet, there have been at least 135 NDINs submitted to FDA for review since January 1, 2017. Of these submissions:

  • 21% (n=28) of the NDINs received an acknowledgment letter from FDA
  • 70% (n=94) of the NDINs received a response letter indicating that the NDIN did not meet one or more of the requirements outlined in the Federal Food, Drug, and Cosmetic Act (FD&C Act)
  • 10% (n=13) of the NDINs received a response letter from FDA, but have not been made publicly available on FDA’s digital docket website4


Lessons Learned

The relatively high number of NDINs which failed to obtain a successful nod from FDA—an acknowledgement letter—makes the situation seem especially bleak for those currently considering introducing an NDI into the marketplace. However, a closer look at the unsuccessful submissions provides valuable insight in identifying pathways toward a successful submission.


Why Did 70% of the NDINs Fail?

A review of the “rejection” response letters issued by FDA indicates that the NDINs rejected did not meet FDA’s requirements in at least one of six general categories:

  1. Definition of an NDI
  2. Specifications and manufacturing process
  3. History of use
  4. Intake assessment
  5. Safety-in-use
  6. Full text references

Approximately 53% (n=50) of the unsuccessful NDINs did not meet two or more of these requirements. For some, these failures were more procedural in nature—i.e., the submission package contained incomplete references. However, there were instances where significant deficiencies in the submission were identified, though there were a few instances where FDA disagreed with the notifier’s conclusion of safety of the new dietary ingredient.

Here, we can take a deeper look at why some of these NDINs did not meet FDA’s bar.


1. Does the ingredient meet FDA’s definition of a dietary ingredient?

In 39 response letters, FDA noted that the ingredient defined in the NDIN submission did not meet the definition of dietary ingredient under 21 U.S.C. § 321(ff) and stated:

A dietary supplement means, among other things, a “product (other than tobacco) intended to supplement the diet that bears or contains one or more of the following dietary ingredients: (A) a vitamin; (B) a mineral; (C) an herb or other botanical; (D) an amino acid; (E) a dietary supplement for use by man to supplement the diet by increasing the total dietary intake; of (F) a concentrate, metabolite, constituent, extract, or combination of any ingredient described in clause (A), (B), (C), (D), or (E).

For many of these rejected submissions, it’s readily apparent that the subject doesn’t meet the definition of a dietary ingredient, as is the case for topical ointments, salves, and other personal care–type products, which accounted for at least 15 rejected NDINs. Other common reasons why FDA rejected the submissions included the use of the ingredient in conventional foods, and statements by the submitter, or legal regulations, that indicated the ingredient qualified as a drug.

It’s important to note that only four of the 39 notifications that FDA rejected on the basis that the ingredient didn’t meet the definition of dietary ingredient were identified as having a secondary reason for rejection. If we omit those 35 NDINs that were rejected solely on the basis of not meeting the definition of a dietary ingredient, then the success and failure percentages are adjusted to 28% and 59%, respectively.

FDA has also made it clear that synthetic forms of most dietary ingredients (with the exception of certain vitamins and amino acids, as noted above) or ingredients produced via fermentation processes, for example derived from engineered E. coli, are ineligible for consideration as dietary ingredients. This issue is a matter of concern for industry as noted by various commenters at the May 16, 2019, FDA public meeting. It was also discussed at the 2019 Rocky Mountain Dietary Supplement Forum. It remains to be seen whether FDA will soften its stance toward synthetic ingredients on a larger scale.

Of the 28 NDINs that were successful—NDINs that received acknowledgement letters—36% (n=10) were for ingredients extracted from botanical sources; 21% (n=6) were for probiotic-category ingredients; and the remaining submissions were for protein/peptide preparations (n=3), algae-derived ingredients (n=3), or other less-categorizable ingredients (n=5).


2. Have the ingredient specifications and manufacturing process been adequately addressed?

FDA noted in its response letters that 54% (n=51) of the rejected NDINs did not contain enough detail regarding the quality parameters of the ingredient and/or the manufacturing process to sufficiently evaluate the safety of the NDI. While many manufacturers understandably wish to protect proprietary processes, enough information about the process and resulting material should be provided to support the assertion that the ingredient is safe for consumption. As noted previously, a master file system might alleviate IP concerns, allowing for a more complete submission for review by FDA.


3. Does the ingredient have a prior history of use?

Another category that proved problematic for 48% (n=45) of the rejected NDINs was the history-of-use or other evidence of safety-in-use requirement. Many of the submissions lacked sufficient detail to establish a history of use, and in a number of notifications, the requirement was ignored entirely. FDA considers these NDINs incomplete.


4. Has an intake assessment been provided?

Under 21 CFR 190.6, NDINs must include information regarding the use levels of the NDI in the dietary supplement. Information about the levels of the NDI per serving and maximum daily servings of the supplement is essential for assessing safety. The proposed uses and use levels should be specific enough to determine an estimated daily intake of the ingredient, which should be supported by safety data in the published literature. A general “take one serving per day” statement is insufficient, whereas a statement indicating “a maximum daily intake of 2 grams per day” of a well-characterized material is likely to provide the necessary specificity. FDA noted that an insufficient intake assessment was observed in 18% (n=17) of the rejected NDINs.


5. Is the safety assessment complete, and does it support safety-in-use?

Ultimately, the purpose of an NDIN is to prepare a complete evaluation of an NDI to support the finding that there is reasonable expectation that the ingredient will not present “significant or unreasonable risk of illness or injury” under the proposed conditions of use. Under 21 CFR 190.6, notifiers are required to provide a basis for the expectation of safety. An evaluation of peer-reviewed, published literature is necessary to support a determination of safety for the NDI. A review of FDA’s response letters found that nearly 40% (n=35) of the rejected NDINs lacked a safety assessment entirely, presented an insufficient safety narrative, or the published literature did not support safety-in-use.


6. Are full-text references included in the submission package?

In addition to providing a basis for the expectation of safety, an additional requirement of each submission per 21 CFR 190.6(b)(4) is that the “notification shall be accompanied by reprints or photostatic copies of those references” cited in support of the notification. Submitting an incomplete NDIN package is a procedural issue that occurred in six of the rejected NDINs. While most were cited as having additional deficiencies, one submission appears to have been rejected solely for not providing the complete full-text references cited in the dossier.

  1. Almendarez S. “NDI Draft Guidance Comments—Industry Has Its Say.” Natural Products Insider. Published online December 15, 2011. Accessed at: www.naturalproductsinsider.com/regulatory/ndi-draft-guidance-commentsindustry-has-its-say
  2. Crane M. “How FDA’s NDI Guidance Could Paralyze Industry.” Nutritional Outlook. Published online August 26, 2016. Accessed at: www.nutritionaloutlook.com/regulatory/how-fdas-ndi-guidance-could-paralyze-industry
  3. FDA website. “Submitted 75-Day Premarket Notifications for New Dietary Ingredients.” Accessed at: www.fda.gov/food/new-dietary-ingredients-ndi-notification-process/submitted-75-day-premarket-notifications-new-dietary-ingredients
  4. Available at: https://www.regulations.gov/
  5. McQuate RS and Kraska RC. “NDI Guidance: NDI versus GRAS Ingredients.” Nutritional Outlook. Published online August 16, 2011. Accessed at: www.nutritionaloutlook.com/regulatory/ndi-guidance-ndi-versus-gras-ingredients
  6. FDA website. GRAS Notices. Available at: https://www.accessdata.fda.gov/scripts/fdcc/?set=GRASNotices
  7. FDA website. “Information About Submitting Notifications for New Dietary Ingredients (Who, What, Where, How). Who needs to submit a notification?” Accessed at: www.fda.gov/food/new-dietary-ingredients-ndi-notification-process/new-dietary-ingredients-dietary-supplements-background-industry
  8. FDA website. “New Dietary Ingredients in Dietary Supplements—Background for Industry.” Definition accessed 11/11/2019. Accessed at: www.fda.gov/food/new-dietary-ingredients-ndi-notification-process/new-dietary-ingredients-dietary-supplements-background-industry#what_is
  9. Federal Register, vol. 62, no. 184, pgs. 49886-49892. “Premarket Notification for a New Dietary Ingredient.” Published September 23, 1997. Accessed 11/11/2019. Accessed at: www.govinfo.gov/content/pkg/FR-1997-09-23/html/97-24737.htm