Can Levothyroxine Pills Be Cut in Half?
Yes, levothyroxine tablets can be safely cut in half for dose adjustment, and this practice is clinically validated and commonly used in thyroid hormone management. 1
Evidence Supporting Tablet Splitting
- A randomized clinical trial in 100 differentiated thyroid cancer patients directly compared taking one-and-a-half 100 mcg tablets (split) versus taking one 100 mcg plus one 50 mcg tablet (whole tablets) for a 150 mcg daily dose 1
- The study found no significant difference in TSH levels, T3 levels, or body weight changes between the split tablet group and the whole tablet group over the study period 1
- This demonstrates that tablet splitting produces equivalent clinical efficacy to whole tablet administration for levothyroxine 1
When Tablet Splitting Is Appropriate
- Dose adjustments of 12.5-25 mcg are frequently recommended when titrating levothyroxine therapy, which often requires splitting tablets 2
- For elderly patients or those with cardiac disease, smaller dose increments of 12.5 mcg are specifically recommended, necessitating tablet splitting 2
- Tablet splitting serves as a practical alternative when specific lower-dose tablets (such as 50 mcg) are not available 1
Practical Considerations
- While tablet splitting is clinically effective, patients in the study preferred taking two whole tablets rather than splitting tablets when given the choice 1
- The recommendation for 12.5-25 mcg dose adjustments is standard across multiple clinical guidelines, implicitly supporting the practice of tablet splitting since these increments often cannot be achieved with whole tablets alone 2
Important Monitoring Requirements
- Regardless of whether tablets are split or whole, TSH and free T4 should be rechecked every 6-8 weeks after any dose adjustment to ensure appropriate thyroid hormone levels 2
- Approximately 25% of patients on levothyroxine are unintentionally maintained on excessive doses, emphasizing the importance of careful dose titration and monitoring 2, 3