Levothyrox France: National medicines agency investigated

The controversy over the ‘new formula’ of the drug has been ongoing since 2017

A photo of the leaflet that comes inside the Levothyrox tablet box
Levothyrox has been at the centre of a long-running saga after a change in its formula in 2017
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The French national medicines agency has announced that it is being investigated for ‘aggravated deception’ in the case of Levothyrox, the thyroid medication whose change in recipe caused uproar.

The Agence nationale de sécurité du médicament et des produits de santé (ANSM) said the investigation had started on December 5.

The French branch of the German pharmaceutical manufacturer, Merck, is also under investigation.

Levothyrox, one of the most common medications to treat underactive thyroid disorders, changed its formula in 2017.

Almost immediately, hundreds of the 2.5 million patients taking the drug in France reported problems and a return of their symptoms, including cramps, headaches, dizziness, brain fog, fatigue, weight gain, and hair loss.

Complaints soon grew into the thousands, and the inquiry even included a manslaughter accusation.

Read more: Levothyrox controversy in France: Merck indicted for ‘deception’

Read more: French Levothyrox inquiry now includes manslaughter

This is despite the manufacturer insisting that the new drug had only been changed in line with ANSM regulations, and that the active ingredients were identical from a medical perspective. Multiple independent investigations concluded that the drug was bioidentical, despite one victims’ association claiming that there were substantial differences.

Then-Health Minister Agnès Buzyn announced an investigation into the case, and made the ‘old formula’ of the drug available nationwide in the meantime. Half of the stocks sold out within two days at the time.

In a statement released yesterday, the ANSM said: “ANSM will make its full contribution to the demonstration of the truth but firmly disputes the reproaches made against it because no criminal offence has been committed.

“The ANSM has never denied the difficulties encountered by some patients when switching to the new formula of Levothyrox and is constantly and daily concerned about the safety and health of patients."

In October, the French branch of Merck revealed that it was also under investigation for the same issue.

One of the victims’ lawyers told FranceInfo: “The victims were beginning to lose hope after five years.”

Yet, one of Merck’s lawyers told the AFP that “the quality of the drug is not in doubt” and that the issues had been caused by “the lack of communication in the plan, built under the authority of ANSM”.

The Cour de cassation has already thrown out Merck’s appeal against a 2020 ruling that it should compensate more than 3,300 users suffering from symptoms experienced after the formula changed.

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