Natural Desiccated Thyroid and the FDA 2026
- Natural Desiccated Thyroid (NDT) remains available.
- The FDA retains its position that it is legally unapproved.
- The FDA approval process is unclear and may be unrealistic for every current manufacturer.
- Could this lead to fewer products being available and higher prices? No one knows.
- We’re still in limbo, so let’s evaluate our options.
One Year Ago
In August 2025, the FDA gave notice in a letter that animal-derived thyroid products meet the legal definition of biological products and require an approved biologics license application, or BLA. It asserted that no current animal-derived product could be legally marketed because it did not have a BLA.
The FDA discussed their actions in light of quality concerns, especially with potency, content uniformity, impurities, and manufacturing controls. It also said the agency believed patients would need “up to 12 months” to transition to an FDA-approved thyroid product before broader action would begin.
Backtrack to 2010
This redefinition of thigs started in 2010 when Congress amended the definition of a biological product to include proteins and products analogous to proteins.
The FDA’s position is that animal-derived thyroid contains thyroglobulin, a large protein that carries T4 and T3, and that marketing applications for products of this kind have therefore had to follow the BLA pathway since March 2020
Patients and Clinicians Respond
Immediately, patients who were taking NDT responded. They organized and pushed back.
In addition, members of Congress asked the FDA to explain the evidence and likely effect on access.
Even the American Thyroid Association urged the agency to preserve access while developing stronger quality standards.
There were also political and legal complications with players in the FDA.
Fast Forward to Now
Things are still in limbo.
On August 5, 2026 the FDA issued a one-page notice stating that work continues.
Natural Desiccated Thyroid is still legally unapproved.
In this notice, it also says that until the FDA issues complete guidance, “it will keep applying risk-based enforcement and prioritize products that pose the highest risk to public health.”
There is no new deadline.
There are no published conditions for manufacturers.
There is no word about compounding.
There IS a confirmation in writing that category-wide removal is not occurring simply because twelve months have passed.
For patients, that is reassuring for now but still leaves them in limbo.
The manufacturers are in limbo too, as there is no word about how much evidence, investment, and manufacturing change are necessary.
Unapproved, but still available
Let’s go back to the 5-point summary at the beginning of this blog.
- Natural Desiccated Thyroid (NDT) remains available.
- The FDA retains its position that it is legally unapproved.
- The FDA approval process is unclear and may be unrealistic for every current manufacturer.
- Could this lead to fewer products being available and higher prices? No one knows.
- We’re still in limbo, so let’s evaluate our options.
If you are taking a Natural Desiccated Thyroid medication and would like to evaluate your options, do call me for an appointment.
Dr. Cheryl Kasdorf is available for this kind of discussion. Just call her at 928-649-9234
