FDA Issues Nationwide Recall of Thyroid Medication Due to Low Potency

• A common thyroid medication is under a voluntary recall after testing found it was less potent than expected.
• The FDA classified a nationwide recall of levothyroxine sodium tablets as Class II on July 17 after testing found the pills were subpotent, according to the agency’s enforcement report.
• Those who have been prescribed the medication are encouraged to continue taking it, and pharmacies are not required to notify patients.

Some people taking a common thyroid medication may have been getting a weaker dose than their doctors prescribed.

The Food and Drug Administration (FDA) classified a nationwide recall of levothyroxine sodium tablets as Class II on July 17 after routine testing found the tablets were subpotent. This means the pills don’t contain the full dose printed on the package, according to the FDA’s enforcement report.

An FDA Class II recall is considered a medium-risk recall that may lead to temporary or reversible health problems, with a low probability of serious harm.

The recall includes seven strengths, from 25 to 150 micrograms (mcg). Lupin Pharmaceuticals, Inc. manufactured the tablets, according to the packaging labels included in a letter to customers that was shared with Healthline.

Major Pharmaceuticals and Cardinal Health distributed them.

Major Pharmaceuticals told its wholesale customers in a letter dated July 10 that the recall began “due to out of specification results obtained during routine stability testing for Assay.” In this case, the assay measured how much active drug a tablet actually holds.

That letter, which was shared with Healthline, stated that the use of the product “is not likely to cause adverse health effects.” It also told its wholesale customers their cooperation was “necessary to prevent patient harm.”

There’s no need to stop taking your medication. The FDA states that stopping a recalled medication can sometimes cause more harm than continuing it. Talk with your doctor or pharmacist about any concerns.

Because most pharmacies pour tablets into their own vials, the recall details won’t be on your bottle. Here’s how to check:

• Call the pharmacy where you last refilled your prescription.
• Ask for the manufacturer, NDC number, and lot number on file.
• Compare those against the recall tables below.

“The overly cautious thing to do is simply check your thyroid hormone levels,” said David Cutler, MD, a family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA.

“If you’re concerned that your thyroid hormone level might be low because you’re taking a subpotent product, simply check your thyroid hormone levels with a blood test to get reassurance that your thyroid hormone levels are okay,” he told Healthline.

Some state regulators have forwarded the recall to pharmacies they license.

The California State Board of Pharmacy went further in its July 15 notice, urging pharmacies across the state to review their own quality assurance and recall procedures to address any gaps.

A spokesperson for the FDA told Healthline that a Class II recall indicates “use of or exposure to a violative product may cause temporary or medically reversible adverse health consequences,” or that “the probability of serious adverse health consequences is remote.”

In plain terms, lasting harm is unlikely, according to the FDA.

Both the FDA and Major Pharmaceuticals said this recall is limited to the retail level. That means pharmacies and health systems that dispense prescriptions to patients are not required to contact them.

Instead, the classification tells pharmacies and distributors to pull the products from their shelves.

Still, a subpotent dose can affect some individuals. Cutler said those who take a weaker tablet than prescribed could develop low thyroid function. Symptoms may include:

The risk of lasting damage is low, he said, because doctors monitor thyroid patients through regular blood work. “You’ll pick it up before there are any significant adverse effects of either a low or high level,” Cutler said.

Thyroid hormones help control metabolism, growth, and other bodily functions, according to a review published by the National Library of Medicine.

Levothyroxine sodium is a synthetic version of T4, one of the two main hormones produced by the thyroid gland.

“It is for people who have low thyroid functions to replace the thyroid hormone,” Cutler said.

Levothyroxine sodium is approved for adults and children for two uses:

Cutler said doctors check thyroid levels every three to six months to catch low or high function early.

Levothyroxine has failed potency testing before. The FDA documented 10 recalls for subpotency, content uniformity, and stability between 1990 and 1997, before the drug required formal FDA approval.

That changed in August 1997, when the FDA declared levothyroxine sodium tablets a “new drug” and required manufacturers to obtain formal approval to continue selling them, according to the federal health agency.

The FDA moved to standardize the drug to reduce potency issues.

Recalls have continued since. Accord Healthcare recalled 82,159 bottles of 25 mcg levothyroxine sodium tablets in June 2025, according to a separate FDA enforcement report. The FDA also classified that recall as Class II for a subpotent drug.

Cutler said the recall itself demonstrates the system working as intended because routine inspections caught the potency problem.

With FDA-approved prescription drugs, “every step along the manufacturing pathway, whether it’s from the drug manufacturer, distribution or their being delivered at the pharmacy, they’re being monitored for their potency,” Cutler said.