The answer isn’t straightforward, so let’s break it down.
First, research specifically examining berberine’s effects on thyroid health is limited, particularly regarding hypothyroidism. However, studies suggest the metametabolic benefits may indirectly support weight management in hypothyroid patients. It is also worth noting that according to recent research, berberine has demonstrated some anticancer properties, including against thyroid cancer, though this does not relate to levothyroxine use.
Also, while there’s no definitive research explicitly investigating the interaction between berberine and levothyroxine, there are two main factors to we should consider:
1. The possibility of drug interactions
Berberine affects liver enzymes (CYP450 enzymes), which metabolize many medications. While levothyroxine is primarily metabolized through deiodination rather than liver enzymes, the possibility of interaction still exists, albeit indirectly.
For instance, berberine could affect medications taken alongside levothyroxine by some hypothyroid patients, such as calcium or iron supplements, which are sometimes used to address deficiencies but are also known to interfere with levothyroxine absorption if taken too closely together.
Interestingly, some animal studies have shown that berberine can affect thyroid hormone levels. However, these studies have not been replicated in humans.
2. Effects on gut absorption
Levothyroxine absorption is highly sensitive to various factors, and even minor disruptions can reduce its effectiveness. Consuming substances like calcium, iron, or fiber close to the levothyroxine dose is known to interfere with its gastrointestinal absorption.
Similarly, berberine may pose absorption challenges due to its potential to alter gut microbiota, intestinal permeability, or inhibit P-glycoprotein, a protein involved in drug transport across cell membranes. These mechanisms could theoretically reduce the absorption and effectiveness of levothyroxine, leading to persistent hypothyroid symptoms.
While there is limited clinical data directly linking berberine to reduced levothyroxine efficacy, some endocrinologists recommend caution when combining supplements like berberine with thyroid medication.
