Introduction to the FDA’s About-Face
An unusual about-face that played out at the Food and Drug Administration over the last week illustrated the power of the “Make America Healthy Again” movement, particularly with its focus on “natural” drugs. Last Thursday, the agency published a statement saying it had concerns about the safety and effectiveness of unapproved thyroid medications made from animal tissue after it received complaints from patients and reports of adverse events. As a result, the FDA said it had notified drugmakers of its “intent to take action” against the products, but added that it wouldn’t do so immediately to give patients time to switch medications.
Animal-Derived Thyroid Pills
The thyroid — a small, butterfly-shaped gland located at the front of the neck — helps regulate how the body uses energy by producing thyroid hormones. When it doesn’t produce enough, it can lead to hypothyroidism, which can cause symptoms including unexplained weight gain, tiredness, sensitivity to cold, changes in menstrual cycles and symptoms of depression and anxiety, according to the Mayo Clinic. The condition is more common in women than men. The standard treatment is prescription thyroid hormone replacement therapy — basically, taking pills that contain the needed thyroid hormones. Typically one of two synthetic hormones, levothyroxine or liothyronine, or a combination of both, are prescribed.
Some patients, however, turn to animal-derived thyroid pills either because they don’t respond well to the synthetic versions or want to take something marketed as natural, said Dr. Michael Weintraub, an endocrinologist at NYU Langone Health in New York City. The pills — which aren’t FDA-approved — are made from dried thyroid glands, usually from pigs, and are sold under brand names like Armour Thyroid, NP Thyroid, Nature-Thyroid and Natural Thyroid, according to the agency. About 1.5 million people in the U.S. were prescribed animal-derived thyroid pills in 2024, the FDA said.
The Backlash
In the days that followed the FDA’s statement, patients and doctors took to social media to voice their opposition. “BREAKING FDA set to BAN natural desiccated thyroid medications. Millions rely on these for hypothyroidism who don’t respond well to synthetic thyroid pharmaceuticals,” read one post from Will Cole, a functional medicine doctor. “Let your voice be heard. The FDA needs to change course on this one.” Dave Asprey, the founder of Bulletproof Coffee, a coffee and supplement brand, wrote: “I found out I had very low thyroid levels in my mid-20s, and Hashimoto’s. Normal synthetic thyroid drugs did not work. Natural thyroid extract worked very well and I have been taking it for more than 25 years without a problem.”
FDA’s Reversal
But on Wednesday evening, FDA Commissioner Marty Makary seemingly reversed course, writing in a post on X that the FDA was committed to pursuing the first-ever approval of desiccated thyroid extract, pending results of the ongoing clinical trials. “In the mean time, we will ensure access for all Americans,” he wrote. Five minutes later, Health Secretary Robert F. Kennedy Jr. responded. “Love your approach of using gold standard science and common sense, @DrMarkaryFDA,” Kennedy wrote.
Safety Concerns
Dr. Pieter Cohen, an associate professor of medicine at Harvard Medical School, said the FDA was correct to issue its initial warning about the thyroid pills, noting that the animal-derived pills aren’t regulated by the agency and can pose significant risks. The FDA-approved synthetic versions usually replace one of two thyroid hormones: T4, the main hormone the thyroid produces, or T3, the active form of T4 that helps regulate energy and metabolism. Companies that make FDA-approved drugs must follow certain regulations, including consistent dosing. The animal-derived versions also contain the thyroid hormones, just like prescription medications, Cohen said, but because they’re unregulated, the amount they contain can be all over the place.
Conclusion
The FDA’s about-face on animal-derived thyroid pills highlights the ongoing debate over the safety and effectiveness of these medications. While some patients and doctors argue that they are a necessary option for those who don’t respond well to synthetic thyroid medications, others raise concerns about the potential risks associated with their use. As the FDA continues to navigate this issue, it is essential to consider the perspectives of all stakeholders and to prioritize the health and well-being of patients.
FAQs
Q: What are animal-derived thyroid pills?
A: Animal-derived thyroid pills are made from dried thyroid glands, usually from pigs, and are sold under brand names like Armour Thyroid, NP Thyroid, Nature-Thyroid and Natural Thyroid.
Q: Are animal-derived thyroid pills FDA-approved?
A: No, animal-derived thyroid pills are not FDA-approved.
Q: What are the potential risks associated with animal-derived thyroid pills?
A: The potential risks associated with animal-derived thyroid pills include inconsistent levels of thyroid hormones, which can lead to serious health problems, such as heart rhythm disturbances and bone degradation.
Q: Why do some patients prefer animal-derived thyroid pills?
A: Some patients prefer animal-derived thyroid pills because they don’t respond well to synthetic thyroid medications or want to take something marketed as natural.
Q: What is the FDA’s current stance on animal-derived thyroid pills?
A: The FDA is committed to pursuing the first-ever approval of desiccated thyroid extract, pending results of the ongoing clinical trials, and will ensure access for all Americans in the meantime.
