Can Subclinical Hypothyroidism Cause Low Libido and Fatigue?

Subclinical hypothyroidism, a slightly high TSH with normal thyroid hormone, rarely explains low libido or constant tiredness. In a meta-analysis of thyroid and sexual function studies, it was not a risk factor for sexual problems. In 21 trials reviewed for a BMJ guideline, thyroid pills did not improve fatigue. Full-blown hypothyroidism is different. It looks a lot like perimenopause and hits desire, arousal and lubrication, so a blood test is worth doing. If yours comes back only borderline, your drop in desire and energy likely has another cause you can treat.

Why do thyroid problems feel so much like perimenopause?

Thyroid disease and the menopause transition share many symptoms. According to a NEJM Clinician review of thyroid disease at midlife, both can bring changes in your cycle, fatigue, poor sleep, mood swings, changes in your skin and hair, and feeling hot. When your periods, sleep and patience all shift at once, it's hard to tell which system is behind it.

Thyroid trouble is also common at this age. In the Study of Women's Health Across the Nation, a large study of midlife women, almost 1 in 10 had an abnormal TSH result. TSH (thyroid-stimulating hormone) is the signal your brain sends to tell your thyroid to work harder. When your thyroid slows down, TSH goes up.

Some symptoms point more toward an underactive thyroid: feeling cold when everyone else is warm, feeling sluggish, dry skin, constipation and heavier periods.

Women in perimenopause describe the change in their own words. One woman in r/Perimenopause listed "The reduced libido. Intolerance towards certain behaviors in those around us."

Mild (subclinical) hypothyroidism may cause mild symptoms or none at all. The American Thyroid Association says that because symptoms vary so much, a blood test is the only way to know for sure.

What's the difference between subclinical and overt hypothyroidism?

Overt hypothyroidism is a real hormone shortage that can flatten your sex drive, and treatment works. Subclinical hypothyroidism is a borderline lab result that usually doesn't do either.

Researchers also suggest one way a truly underactive thyroid can dampen desire. Long-term hypothyroidism can raise prolactin, a hormone closely linked to low sexual desire in women, and it may also lower lubrication and orgasm.

Does a slightly high TSH after 40 mean anything?

Often it means you're getting older, not that your thyroid is failing. TSH rises naturally with age in women, especially after 50. An American Thyroid Association summary of a Dutch study of 7.6 million TSH tests put the upper normal limit at 4.0 mIU/L at age 50 and 6.0 at age 90. When age-specific ranges were used, fewer women aged 50 to 60 counted as having subclinical hypothyroidism: 8.6% instead of 13.1%.

One high reading is not a diagnosis. Repeat the thyroid panel in 3 to 6 months before calling it subclinical hypothyroidism.

Antibodies change the picture. Positive TPO antibodies mean your immune system is targeting your thyroid, the most common cause of an underactive thyroid. If you have them, the American Thyroid Association says to recheck your TSH at least once a year.

A 2019 BMJ guideline panel strongly recommends against thyroid pills for almost all adults with subclinical hypothyroidism. The advice does not apply to women trying to get pregnant or to anyone with a TSH above 20 mIU/L. It may not apply to people with severe symptoms or to adults 30 and under. Earlier advice was more open to treating some women, so tell your clinical team about your results, your symptoms and any pregnancy plans.

Which thyroid test should I get, and what does it cost?

Get a test that includes free T4, because that's what separates overt hypothyroidism from a borderline TSH. If you have a family history of thyroid disease or want to know your autoimmune risk, a panel with antibodies tells you more.

Before a Labcorp thyroid test, stop any supplement containing biotin for at least 72 hours. Many hair and nail gummies contain it. Many self-ordered tests qualify for HSA or FSA funds. Prices change, so check the total at checkout.

If it's not my thyroid, what can bring back my sex drive and energy?

A normal or borderline thyroid result is useful news. It points you back toward perimenopause and the other changes in your life, and you can work on those directly. You don't have to wait months for a TSH number to move before you go after the sex drive and energy you miss.

Our clinical team can prescribe bioidentical estrogen, PT-141 or kisspeptin for libido, and NAD+ for energy, if one fits your goal.

If you already take thyroid medicine, tell your clinical team before starting or stopping estrogen pills. Oral estrogen raises a protein that binds thyroid hormone, which lowers your free T4, so your thyroid dose may need to go up. Recheck TSH 6 to 8 weeks after any change.

Don't ask for thyroid pills to lose weight. The FDA label for Synthroid (levothyroxine) carries a boxed warning against it. In people with normal thyroid levels, usual doses don't cause weight loss, and larger doses can cause serious or even life-threatening harm.

If your thyroid checks out and you still want your sex drive and your afternoon energy back, take the quiz to start a plan with our clinical team built around those goals.