Low progesterone? You might want to check your thyroid. ๐Ÿฆ‹๐Ÿ‘‡

progesterone thyroid
Low progesterone? You might want to check your thyroid. ๐Ÿฆ‹๐Ÿ‘‡

Relatively recent literature aimed to better understand the connection between thyroid hormone levels and normal menstrual cycles. The authors measured thyroid hormone levels in conjunction and related these results to their study group’s menstrual cycles.

The authors found that women with the highest levels of T4 (compared to those with medium or low levels) had higher levels of progesterone throughout both the follicular and luteal phases. T4 is what gets converted into T3, the more potent thyroid hormone.

They also found that total and free T3 levels were associated with higher progesterone, especially estrogen levels.

The authors concluded that normal levels of thyroid hormone positively influenced the levels of estrogen and progesterone throughout the entire menstrual cycle. And that even at normal ranges, thyroid hormones can play a role in the female menstrual cycle and hormone levels.

TLDR: Your thyroid levels can influence your progesterone levels.

This isn’t the first time I’ve spoken about the relationship between your menstrual cycle and thyroid health. This piece of literature provides even more information about how they’re connected, which to me, points to just how important thyroid health is if you’re trying to optimize your progesterone to get pregnant.

Want to learn how to support your thyroid health for fertility? Check out my pregnancy prep eCourse, where I go deep on how you can optimize your thyroid health and progesterone levels to improve your chances of pregnancy (and have a healthy one at that). 


Not medical advice.

Jacobson, M.H. Howards, P.P. Darrow, L.P. Meadows, J.W. Kesner, J.S. Spencer, J.B. Terrell, M.L. Marcus, M. (2018). Thyroid hormones and menstrual cycle function in a longitudinal cohort of premenopausal women. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5980701/.

This month I want to share a small but interesting study with you by Jacobson et al. called Thyroid hormones and menstrual cycle function in a longitudinal cohort of premenopausal women.

This is not a groundbreaking study per se, but I thought it was valuable because it highlights the relationships between thyroid hormones and sex hormones through the menstrual cycle. Below are a few things that stuck out to me. ๐Ÿ‘‡

If you’re wanting more, I’ll be talking about optimizing thyroid health at length in Conscious Conception, with both a lesson on general thyroid support as well as trying to conceive with various thyroid conditions (hypo, hyper, Hashi’s, Graves’, and no thyroid). So stay tuned. :)


TTC? Get empowered with Conscious Conception, the ultimate fertility blueprint created to help you optimize your fertility and enter pregnancy empowered.


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