The US Food and Drug Administration (FDA) has reaffirmed that desiccated thyroid extract (DTE) products will remain available to patients while manufacturers transition toward biologics licensing requirements, in a move that clarifies the regulatory pathway for a long-standing class of thyroid medicines.

The update follows earlier communications from the agency outlining expectations for DTE manufacturers, importers and distributors, and confirms that the FDA will apply a risk-based enforcement approach while companies progress through the biologics approval process.

DTE products are used by an estimated 1.5 million patients in the United States to treat hypothyroidism, a chronic condition in which the thyroid gland does not produce sufficient hormones to regulate metabolism, energy balance and organ function.

Under the updated approach, the FDA said it will prioritise enforcement action against manufacturers failing to meet quality standards, while also planning draft guidance on the conditions under which DTE products may remain on the market beyond August 2026 as companies pursue full biologics approval.

The move effectively maintains short-term patient access while reinforcing the agency’s longer-term position that animal-derived thyroid products must transition through the Biologics License Application (BLA) pathway.

Acella Pharmaceuticals, a manufacturer of NP Thyroid (thyroid tablets, USP), welcomed the clarification.

“We appreciate the FDA’s thoughtful consideration in providing this update as it supports patient access to these essential medicines while we progress toward FDA review,” said Art Deas, chief executive officer of Alora Pharmaceuticals, parent company of Acella Pharmaceuticals.

The company said it remains focused on quality standards and affordability for patients reliant on DTE therapy.

In September 2025, Acella and its sister company Neuvosyn Laboratories reported positive topline results from a Phase 2 randomized controlled trial of North Star, an investigational DTE product intended to support a future BLA submission.

The company said it intends to pursue approval without premium pricing expectations, highlighting affordability as a central positioning strategy as regulatory requirements evolve.

The FDA also reiterated its commitment to ensuring safety oversight of unapproved animal-derived thyroid medications currently in use, signalling continued scrutiny of manufacturing standards during the transition period.

The regulatory shift is part of a broader effort to formalise legacy therapies that predate modern approval frameworks, while maintaining continuity of care for patients dependent on established treatments.