A New FDA Rule Could Open the Door for an Ingredient That's Currently Locked Out of Supplements

Aug 7
4 min read

Woman in orange sweater places a Nouri Probiotic & Omega-3 bottle into a brown suede tote indoors.

Most dietary supplement regulation moves in one direction: tighter restrictions, more disclosure requirements, narrower claims language. So it's genuinely worth pausing on a rule that's headed the opposite way, one that could expand what's legally permissible rather than restrict it.

What the Rule Would Actually Do

Under RIN 0910-AI91, the FDA has signaled intent to issue a rule finding that a specific ingredient is not excluded from the legal definition of a "dietary supplement" under the Federal Food, Drug, and Cosmetic Act. According to the agency's own rule description, if finalized, this would provide by regulation that a specific ingredient is not excluded from the dietary supplement definition in the FD&C Act. Products containing this ingredient could then be lawfully marketed as dietary supplements, provided they otherwise meet the full definition under section 201(ff) and don't run afoul of the Act elsewhere.

The rule would also clarify that adding this ingredient to a dietary supplement would not be treated as a prohibited act under section 301(ll). In plain terms: right now, this ingredient sits outside the legal boundary of what can be marketed as a dietary supplement. This rulemaking is the formal process for potentially moving that boundary, using the discretion Congress specifically gave the FDA to do exactly this.

The current target on the Unified Agenda points to a Notice of Proposed Rulemaking, originally projected for January 2026. As with most Unified Agenda timelines, that date should be treated as a planning signal rather than a guarantee, but it does indicate the agency considers this an active, near-term priority rather than a long-term or back-burner item.

The Legal Mechanism Behind It

Section 201(ff) of the FD&C Act authorizes the FDA, in its discretion, to issue a rule after notice and comment, finding that a given article would be lawful under the Act despite sitting in what would otherwise be an excluded category. This is a formal, evidence-based rulemaking process, not an informal determination or enforcement discretion memo. That distinction matters, because a rule issued this way carries the weight of a binding regulation once finalized, not just a policy statement the agency could reverse without another full rulemaking cycle.

Why This Is Bigger Than Just One Ingredient

The specific ingredient at issue matters enormously to the brands directly affected, obviously. But the mechanism matters to nearly everyone in the supplement space, regardless of what's in your current product line. Watching how this particular rule unfolds, what evidence the FDA relies on, what conditions it attaches to a favorable determination, and how it reasons through the section 201(ff) exclusion is a useful and fairly rare preview of how the agency is willing to use that discretion going forward.

If your product line has ever included, or considered including, something that lives in a similar in-between category, whether because of how it's sourced, how it's classified elsewhere in the FD&C Act, or a history of enforcement uncertainty around it, this rule is worth tracking closely. It's a live, real-time example of the pathway that could eventually apply to your own ingredient questions.

The Mistake Brands Tend to Make Here

The natural instinct with a rule like this is to wait until it's finalized before doing anything at all. That's usually the wrong call, for a fairly simple reason: the proposed rule stage, once the NPRM actually publishes, is when the real boundaries of the rule get shaped. Public comments genuinely influence final language on rules like this, especially on definitional questions, where the practical business impact depends heavily on the specific conditions the agency ultimately attaches to any "lawful" determination.

If you have a stake in how this ingredient, or ingredients like it, get treated under the FD&C Act, the NPRM stage is your real access point to that process. Waiting for the final rule to comment means showing up after the decisions that actually matter have already been made and locked in.

What to Do While This Moves Through the Process

Confirm whether this specific ingredient, or anything structurally similar in your current or planned portfolio, is directly affected, and map out concretely what a favorable determination would mean for your product lineup.
Watch for the NPRM's actual publication and read closely the specific conditions attached to any "lawful" determination. On a rule like this, the conditions and limitations genuinely matter as much as the headline outcome.
If the outcome affects your business meaningfully, participate in the comment period directly. This is exactly the kind of technical, evidence-driven rulemaking where a well-reasoned, specific comment can shape the final regulatory language.
Use this rulemaking as a working case study for how the FDA approaches definitional gray areas under section 201(ff) generally, even if this particular ingredient isn't one your business touches today.
Coordinate early between regulatory, formulation, and marketing teams so that if the rule finalizes favorably, you're positioned to move on labeling and go-to-market claims quickly rather than starting that conversation from scratch.

The Bottom Line

Rules that expand what's legally permissible in this category don't come around often. When one does, the brands paying attention early, watching the NPRM, engaging in the comment period, and mapping the business implications ahead of time are the ones positioned to actually benefit from it. Everyone else finds out about the opportunity after the window to meaningfully weigh in has already closed.

If you're trying to figure out whether this rule touches your product portfolio, or what a comment on it should say once the proposed rule drops, that's worth sorting out well ahead of the NPRM's actual publication.