Hypothyroidism study finds controversial desiccated thyroid as effective as synthetic drugs

When it comes to hypothyroidism, a condition in which the thyroid produces too little thyroid hormones, the standard treatment is to take a synthetic form of the T4 thyroid hormone. Called levothyroxine and sold under brand names like Synthroid, this drug replaced older, riskier treatments that involved consuming minuscule quantities of desiccated thyroid sourced from pigs. For many with hypothyroidism, this decision to use synthetic drugs over desiccated thyroid remains a big controversy.

When it comes to hypothyroidism, the common — and quite effective for most patients — solution is to prescribe synthetic T4 hormone, which the body can also convert into the T3 hormone. In a small number of patients, however, the body is unable to make this conversion, forcing them to take a combination pill that includes both T3 and T4 hormones — this is often done in the form of desiccated thyroid tablets.

A percentage of hypothyroidism patients who don't have a T3/T4 conversion problem may still complain about symptoms experienced when taking the synthetic levothyroxine, prompting some to seek out desiccated thyroid as an alternative. This practice remains controversial and is generally discouraged among doctors for a variety of reasons, including the difficulty in getting a consistent dose of the thyroid hormone in each tablet.

New research from Kaiser Permanente tosses some new data into the mix, reporting that desiccated thyroid is as effective of treatment for hypothyroidism patients as the more common synthetic alternative. The findings were described as 'unanticipated' due to the aforementioned potential for thyroid hormone amounts to vary from batch to batch.

The study used TSH levels as the indicator of how stable the participants' thyroid hormones were over a three-year period. No difference was found between the desiccated and synthetic thyroid treatment groups' TSH levels during that period of time. The researchers explain that based on the results, using desiccated thyroid in place of synthetic hormones may be an option for patients who report continued symptoms while taking levothyroxine.