https://www.sexhealthmatters.org/sex-health-blog/thyroid-disorders-and-mens-sexual-health
What does the thyroid have to do with sexual problems?
Thyroid disorders, particularly hyperthyroidism and hypothyroidism, have been associated with erectile dysfunction (ED) – the inability to get and keep an erection firm enough for sex – as well as other sexual problems like low libido, premature ejaculation, and delayed ejaculation. However, experts aren’t completely sure why the conditions are related.
Research published in the Journal of Clinical Endocrinology & Metabolism in 2008 found that in 71 men with thyroid problems, 79% had some degree of ED. Erection problems were more common in men with hypothyroidism than hyperthyroidism. Men saw their erections improve with treatment for their thyroid disorder.
In 2005, the same journal published a study that looked at ED as well as other sexual dysfunctions in 48 men. Thirty-four men had hyperthyroidism and the remaining 14 had hypothyroidism. The men’s sexual function was assessed while they were experiencing thyroid symptoms and again 8 to 16 weeks after their thyroid hormone levels were restored to a normal range.
At the start of the study, the researchers found that about 64% of the men with hypothyroidism had low sexual desire, ED, or delayed ejaculation. Around 7% had premature ejaculation.
Among men who had hyperthyroidism, half had premature ejaculation, 18% had low libido, 15% had ED, and 3% had delayed ejaculation.
Men’s symptoms generally improved with thyroid treatment, however. For example, premature ejaculation prevalence dropped from 50% to 15% in the hyperthyroid men.