Natural Desiccated Thyroid (NDT): FDA Signals Policy Shift in March 2026 Guidance

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Listen to the Paloma podcast update on the FDA's policy regarding NDT

For patients with hypothyroidism who rely on natural desiccated thyroid (NDT) medications, the past year has felt like a rollercoaster. One moment, these long-standing treatments seemed headed for sudden disappearance; the next, they were granted a reprieve—but without real certainty. As regulatory shifts, political pressure, and insurance decisions collide, patients are left asking a simple but urgent question: Will I still have access to the medication that works for me? Let’s take a look at March 2026 developments that answer that question, at least in part.

On August 6, 2025, the U.S. Food and Drug Administration (FDA) sent letters to natural desiccated thyroid (NDT) manufacturers stating its intent to take enforcement action regarding animal-derived thyroid medication. At the same time, the FDA published a web page outlining its position regarding NDT.

The FDA had already classified NDT as a biologic drug, but it announced that it was moving the enforcement deadline from 2029 to August 2026. After that point, any NDT product without a Biologics License Application (BLA) would become illegal to market and sell after that date.

An uproar from patients, practitioners, and some drug manufacturers resulted. Paloma also covered this issue extensively and actively advocated on behalf of patients with the FDA. [For details and in-depth information on the history of the 2025 NDT controversy, see our article What’s Happening With Natural Desiccated Thyroid Drugs? (Updated September 2025).]

Moving the enforcement up by 3 years, while NDT products were still in the earliest stages of the BLA process, meant they would likely go off the market in 2026.

Patients who relied on NDT as their thyroid hormone replacement to treat their hypothyroidism were told by the FDA that they should talk to their physicians and switch to T4-only medications like synthetic levothyroxine. However, this option is not functional for many patients whose treatment has already failed on levothyroxine. Removing NDT from the market would leave patients facing an uncertain – and frightening – future without access to life-saving treatment.

After a series of political controversies and the abrupt departure from the FDA of George Tidmarsh, MD, an outspoken NDT opponent, FDA head Dr. Marty Makary posted on X that the “FDA is committed to pursuing the first-ever approval of desiccated thyroid extract, pending results of the ongoing clinical trials. In the meantime, we will ensure access for all Americans.” HHS Secretary RFK Jr. reposted this message approvingly. While this signaled a potential softening of the FDA’s stance regarding NDT, these social media promises from FDA leadership were not formalized with any official guidance or policy decisions.

While patients remained in limbo, manufacturers, practitioners, patients, and advocates raised their voices. Pharmacist and People’s Pharmacy radio and podcast host Joe Graedon wrote in late September 2025 that “The FDA’s plan to ban natural thyroid is not just ill-advised. It could create chaos for many people who rely on it for hypothyroidism.” Joe and Terry Graedon also featured the topic in their November 2025 episode of the People’s Pharmacy show, “Why Is the FDA Planning to Ban Natural Desiccated Thyroid?”

At the same time, a Change.org thyroid advocacy petition titled “Save NDT — Protect Women’s Health and Patient Choice” directed almost 10,000 signatures to Congress and the FDA.

On March 11, 2026, the FDA quietly updated its guidance on natural desiccated thyroid (NDT) medications and issued a new letter to manufacturers, importers, and distributors. This new guidance represents a significant policy reversal from its aggressive stance in August 2025.

Where the original guidance threatened enforcement action against NDT manufacturers, set a hard removal deadline of August 2026, and explicitly directed patients to transition away from NDT products like Armour Thyroid and NP Thyroid, the revised guidance strips out all that language. In its place, the FDA now frames the situation as an active approval process in progress, and commits to ensuring patient access while manufacturers pursue FDA approval. They have also replaced the hard deadline with a softer promise to issue “compliance priorities” guidance by August 2026 using a risk-based enforcement approach.

In practical terms, the FDA has shifted from “these products must go” to “these products can stay while we work this out” — a shift widely attributed to political pressure from FDA Commissioner Dr. Marty Makary and HHS Secretary RFK Jr., both of whom had publicly signaled their support for NDT access. Critically, NDT medications remain technically unapproved, meaning the long-term picture is still unsettled, but the immediate threat of removal has been lifted.

The March 2026 web page has removed the following from the August 2025 version:

The entire “What you should do” section directed at patients

The August 2025 version included explicit instructions for patients and their practitioners to transition away from NDT products and switch to FDA-approved synthetic alternatives. In the March 2026 release, this entire section was deleted.

The August 6, 2025, manufacturer letter

The original document referenced the letter sent to NDT manufacturers notifying them of enforcement action. In the March 2026 version, all references to those past letters were removed.

The hard August 2026 enforcement deadline

The August 2025 version stated that NDT products without a Biologics License Application (BLA) would face enforcement action within a year (putting the deadline at August 2026). That deadline language is gone.

Several important additions were made in the March 2026 version.

FDA commitment to patient access

New language stating the FDA is “committed to ensuring safety of patients currently using unapproved animal-derived thyroid medications while manufacturers are working toward FDA approval” — notably framing this as an ongoing process, not an imminent cutoff.

Reference to ongoing clinical trials

The March 2026 version acknowledges that pharmaceutical companies are actively working toward approval, suggesting the FDA is giving the process time to play out rather than forcing products off the market.

“Risk-based enforcement” language

A new section states the FDA intends to issue guidance on “compliance priorities by August 2026” and will apply a risk-based approach in the meantime — meaning NDT stays on the market while that process unfolds.

Softened patient recommendations

Instead of “switch to an approved product,” the March version simply recommends that patients “talk to their doctor” and lists various professional bodies as resources—a much more neutral stance.

The March 12 update is a notable change to the FDA’s published guidance and appears to be a more patient-access-friendly approach. It is essentially a meaningful policy retreat and good news for patients with an underactive thyroid gland who rely on NDT drugs.

The FDA went from “NDT products must come off the market by August 2026” to “we’ll issue guidance on compliance priorities by August 2026 while taking a risk-based approach.” That’s the difference between a removal deadline and a monitoring posture.

While there’s no guarantee of permanent availability, it appears that the FDA is signaling that NDT will remain available until BLA-approved NDT is available.
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Even as the FDA pulls back from its threatened removal of NDT medications, patients aren’t entirely out of the woods. The Graves’ Disease and Thyroid Foundation has flagged a significant and separate obstacle: CVS/Caremark, one of the largest pharmacy benefit managers (PBMs) in the United States, is removing NDT medications — including Armour Thyroid and NP Thyroid — from its formulary, effective April 1, 2026. This decision is made independently of the FDA and operates through an entirely different mechanism.

While the FDA controls whether a drug can legally be sold, PBMs like CVS/Caremark control whether a drug is covered by insurance — and a formulary removal means patients whose prescription coverage runs through CVS/Caremark may suddenly find their NDT medication is no longer covered, leaving them to pay full out-of-pocket costs.

For many patients, this is a serious financial barrier. NDT medications are not cheap, and patients who have been stable on Armour Thyroid or NP Thyroid for years — sometimes decades — may face pressure from their insurer or pharmacy benefit manager to switch to levothyroxine. This synthetic thyroid hormone is FDA-approved and widely covered by insurance. While levothyroxine works well for many hypothyroid patients, a meaningful subset of patients report feeling better on NDT, which contains both T3 and T4 thyroid hormones rather than T4 alone, and have switched to NDT specifically because levothyroxine was insufficient for them. Being pushed back onto a medication that didn’t work is not a neutral inconvenience for these patients — it can have real consequences for quality of life, energy, mood, weight, and overall health.

It’s also worth understanding what CVS/Caremark’s formulary decision does and does not mean. It does not mean NDT medications are unavailable — patients can still obtain them at pharmacies, including many independent pharmacies and mail-order options. It does not mean a doctor cannot prescribe them. What it does mean is that patients covered under plans administered by CVS/Caremark will likely need to pay out of pocket, seek a formulary exception from their insurer, or work with their doctor to appeal the coverage decision. Some patients may also have the option of switching to a different pharmacy benefit manager if their employer offers plan choices, though this is not available to everyone.

The timing is particularly frustrating for the NDT patient community: just as the FDA’s posture softens and the immediate threat of a market removal recedes, a major insurance gatekeeper is moving in the opposite direction. This underscores the broader reality that FDA approval status and insurance coverage are two separate battles, and winning one doesn’t automatically resolve the other. Patients currently on NDT medications who are covered through CVS/Caremark are strongly encouraged to contact their prescribing physician before April 1 to discuss options, explore whether a formulary exception can be requested, or ensure they have an adequate supply while they navigate the coverage change.

Is CVS/Caremark your pharmacy benefit manager (PBM)?

Understanding which health insurance companies use CVS/Caremark can be surprisingly confusing—because it’s pharmacy benefit manager (PBM), NOT a health insurer. CVS Caremark is one of the “Big 3” PBMs (along with OptumRx and Express Scripts) managing prescriptions for tens of millions of Americans across many insurers and employer plans.

PBMs like CVS/Caremark operates behind the scenes to manage prescription drug coverage for a wide range of insurers, employer plans, and government programs. As a result, there isn’t a single, definitive list of “insurance companies that use CVS/Caremark.” The relationship depends onyou’re your specific plan, your employer, and even the year.

One of the most straightforward connections is with Aetna, which is owned by CVS Health. In most cases, Aetna plans—whether employer-sponsored, individual, or Medicare—use CVS/Caremark to handle prescription benefits. This vertical integration means that for many Aetna members, Caremark is essentially the default pharmacy benefits provider.

Other insurers may also use CVS Caremark, but less consistently. For example, some regional plans within the Blue Cross Blue Shield system contract with Caremark, while others rely on different PBMs. The same variability applies to Medicaid managed care plans and Medicare Part D coverage, where CVS Caremark may administer benefits for certain plans in some states but not others. Large employers add another layer of complexity—many self-funded companies contract directly with CVS Caremark, meaning employees may have Caremark even if their insurance card carries a different brand name.

Ultimately, the key takeaway is that CVS Caremark is plan-specific, not insurer-specific. Two people with the same insurance company can have completely different pharmacy benefit managers depending on their employer or plan design.

The easiest ways to confirm are:

• Check your insurance card for the “Caremark” name
• Review your prescription benefits
• Look for a BIN number like 004336 (commonly associated with Caremark)
• Requirement to use a mail-order pharmacy through CVS
• Requirement to use CVS for maintenance meds

At Paloma, we closely monitor regulatory updates, emerging research, and real-world patient experiences to stay ahead of changes that impact thyroid care. Our team is committed to advocating for patient choice and optimal treatment—especially when it comes to treatments like NDT that can be life-changing for those who don’t thrive on standard therapies.

Paloma works with patients to navigate evolving guidelines, insurance challenges, and treatment options, ensuring that care is individualized—not one-size-fits-all. Whether you’re trying to maintain access to NDT, optimize your current thyroid medication, or explore alternatives, Paloma’s clinicians are here to support you with evidence-based, patient-centered care every step of the way.

Are NDT medications being taken off the market?

Not right now. The FDA has stepped back from its earlier plan to remove NDT drugs by August 2026 and is allowing them to remain available while approval processes continue.

Are NDT drugs FDA-approved?

Currently, NDT medications are not formally FDA-approved, but they are legally available. Manufacturers are working toward approval through ongoing clinical trials and regulatory pathways.

Why do some patients prefer NDT over levothyroxine?

NDT contains both T4 and T3 thyroid hormones, whereas levothyroxine provides only T4. Some patients report better symptom control and quality of life with this combination.

What does “risk-based enforcement” mean?

It means the FDA will prioritize safety concerns rather than enforcing an immediate ban. This approach allows NDT to remain on the market while regulators evaluate the data and determine next steps.

Will NDT be available long-term?

That’s still unclear. Availability will likely depend on whether manufacturers successfully obtain FDA biologic BLA approval, but the immediate risk of removal has decreased.

Why is CVS/Caremark dropping coverage for NDT?

Pharmacy benefit managers make independent coverage decisions, often based on cost and approval status. Even if a drug is legal, it may not be covered by insurance.

Can I still get NDT if my insurance won’t cover it?

Yes, but you may need to pay out of pocket, request a formulary exception, or work with your doctor to appeal the decision.

What should I do if I’m currently taking NDT?

Don’t make changes abruptly. Talk to your healthcare provider about your options, ensure you have a consistent supply, and create a plan in case your coverage or access changes.

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