As per a new study a commonly used poll for treating underactive thyroid may be associated with bone loss. The study will be presented next week at the annual meeting of the Radiological Society of North America in Chicago.
Levothyroxine (LT4), the second most commonly prescribed medication in older adults is a synthetic version of the hormone produced by the thyroid gland. In a study of nearly 450 older adults, including 81 taking levothyroxine, the drug was associated with greater loss of total body bone mass and bone density over a median follow-up of 6.3 years. This was true even though users’ thyroid hormone levels were in the normal range.
“Our study suggests that even when following current guidelines, levothyroxine use appears to be associated with greater bone loss in older adults,” Dr. Shadpour Demehri of Johns Hopkins University School of Medicine in Baltimore, who worked on the study, said in a statement.
The results showed that levothyroxine use was associated with greater loss of total body bone mass and bone density—even in participants whose TSH levels were within the normal range—over a median follow-up of 6.3 years. This remained true when taking into account baseline TSH and other risk factors, the researchers have said.

Levothyroxine is a synthetic form of the thyroid hormone thyroxine (T4), used to treat conditions related to low thyroid hormone levels, such as hypothyroidism. It works by replacing or supplementing the natural hormone produced by the thyroid gland, essential for regulating the body’s metabolism, energy production, and overall development.
This medication is also prescribed for individuals with goiter or thyroid cancer, often following thyroidectomy or radioactive iodine treatment, to suppress thyroid-stimulating hormone (TSH) levels and prevent recurrence. Levothyroxine is available in various dosages and is typically taken orally, preferably on an empty stomach in the morning for optimal absorption.