How a thyroid hormone pill changes other body hormones
Effect of Thyroid Status Modulation on Pituitary and Peripheral Hormone Concentrations in Healthy Older Subjects
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
T3 increased LH and testosterone—but rhTSH did not—even though both modulate thyroid status.
Scientists expected both interventions to have similar effects since they both alter thyroid signaling. But only direct T3 affected the reproductive axis, suggesting T3 has unique, non-thyroid roles.
Practical Takeaways
If you're an older adult with low energy or low libido, ask your doctor to check your thyroid and testosterone together—this study suggests they may be linked.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
T3 increased LH and testosterone—but rhTSH did not—even though both modulate thyroid status.
Scientists expected both interventions to have similar effects since they both alter thyroid signaling. But only direct T3 affected the reproductive axis, suggesting T3 has unique, non-thyroid roles.
Practical Takeaways
If you're an older adult with low energy or low libido, ask your doctor to check your thyroid and testosterone together—this study suggests they may be linked.
Publication
Journal
Neuroendocrinology
Year
2024
Authors
Evie van der Spoel, Saskia Cornet, Ana Zutinic, Bart E. Ballieux, P. Slagboom, H. Pijl, D. van Heemst
Related Content
Claims (6)
Thyroid hormone doesn’t directly make sex hormones like testosterone or estrogen, but it helps the body’s sex glands work properly so they can produce these hormones at the right levels.
Taking one pill of a thyroid hormone called T3 might cause older men to temporarily produce more testosterone and a related hormone, which could help explain why thyroid and sex hormones might be connected as men age.
In older adults who are healthy, giving them thyroid hormones (either through a shot or a pill) can make a key growth-related protein called IGF-1 go up by 6–9% in just one day — and this might happen even if their growth hormone levels don’t change.
When older adults get more thyroid hormone—either through a shot or a pill—their prolactin levels drop by about 8–12% in just a couple of days, and this drop is bigger in men, suggesting thyroid hormone naturally lowers prolactin no matter how you give it or whether you're male or female.
When older adults without thyroid problems are given hormones that boost thyroid activity, their stress hormone (cortisol) drops by about 12–16% over a couple of days, which suggests that the thyroid and stress systems talk to each other.