Low libido? The hormone labs worth checking before any treatment

Start with blood work that can actually change your treatment plan. For men, that means two early morning total testosterone tests, plus free testosterone or SHBG, LH and FSH, prolactin, estradiol, TSH and hemoglobin A1c. For women, there is no testosterone number that diagnoses low desire, so labs focus on thyroid, prolactin, iron and the FSH and estradiol picture around perimenopause, always read alongside your symptoms and medications.

That order matters because of how hormone therapy and libido really connect. The Endocrine Society's 2018 testosterone therapy guideline supports treating men when symptoms line up with consistently low testosterone, and in that group therapy can improve sexual desire. For women, The Menopause Society's 2022 hormone therapy position statement frames hormone therapy as a treatment for menopause symptoms such as hot flashes and vaginal dryness, not as a libido drug on its own. So the honest answer to "does hormone therapy improve libido?" is: it helps when a real deficiency or a menopause-related problem is driving the symptom. Labs are how you find out which one you have.

The men's lab checklist

Testosterone is the first test, but it should never be the only one. The Endocrine Society recommends diagnosing low testosterone (hypogonadism) only when you have symptoms of deficiency and your testosterone is unequivocally and consistently low, confirmed by repeating a morning fasting measurement. MedlinePlus notes that testosterone changes through the day and is usually highest in the morning, which is why an afternoon draw can make a normal level look low.

Test Why it matters Practical note
Total testosterone, on two mornings Confirms levels are truly low, not just low on one day Fasting, early morning draws on separate days
Free testosterone and SHBG SHBG binds testosterone, so total testosterone alone can mislead when SHBG is high or low Most useful when total testosterone sits near the lower end of normal, or with obesity, diabetes or aging
LH and FSH Show whether the problem starts in the testes or in the pituitary and brain Also central to fertility planning
Prolactin High prolactin suppresses the reproductive axis and can lower desire A raised result needs a repeat test and follow-up
Estradiol Made from testosterone and part of male sexual function Especially relevant with breast tenderness or once treatment starts
TSH Thyroid problems can cause fatigue and low drive Free T4 is usually added if TSH is abnormal
Hemoglobin A1c Diabetes and insulin resistance are closely tied to low testosterone and erection problems Flags metabolic risk worth treating on its own

LH and FSH deserve special attention if you might want children. The Endocrine Society recommends against testosterone therapy in men planning fertility in the near term, because outside testosterone suppresses the signals that drive sperm production. That is one reason BioCure's men's program has three tiers: bioOptimize for foundational support, bioRestore for medications that raise your own testosterone without direct replacement, and bioTest for full replacement with ongoing monitoring. You can read more on our testosterone therapy page.

The women's lab checklist

Here is the part most articles skip: there is no testosterone cutoff that diagnoses low desire in women. Hypoactive sexual desire disorder (HSDD) is diagnosed clinically, based on a persistent lack of desire that causes you distress, not on a blood number. Women's testosterone levels are low to begin with, many standard assays were built for male ranges, and measured levels do not track neatly with how much desire a woman feels. There is also no FDA-approved testosterone product for women in the United States, so any testosterone use is off label and should follow a full evaluation.

That does not make labs pointless. It changes what they are for: finding treatable causes that sit underneath low desire.

Test Why it matters Practical note
FSH and estradiol Context for perimenopause and menopause Values swing a lot in perimenopause, so one result rarely settles the question; your cycle history matters as much
TSH An under or overactive thyroid can affect energy, mood and desire Free T4 is usually added if TSH is abnormal
Prolactin High levels can disrupt cycles and dampen desire Mention irregular periods or nipple discharge
Ferritin and CBC Low iron stores, common with heavy periods, drain energy Ferritin shows stores better than hemoglobin alone
Total testosterone (optional) A baseline if testosterone is being considered, or to check for excess with PCOS-type symptoms Not a diagnostic test for low desire

If you use hormonal birth control or hormone therapy, tell your clinician before you test, because both can change how these results read. And if desire dropped alongside vaginal dryness or painful sex after menopause, that points toward genitourinary syndrome of menopause. The Menopause Society's 2022 position statement supports low-dose vaginal estrogen for those symptoms, and treating pain often helps desire return. For a broader look at what drives desire differently in men and women, see the real reasons behind male and female sex drives.

Review your medications before you blame your hormones

A medication review costs nothing and belongs on the checklist before any hormone is prescribed. Several commonly used prescription drugs list sexual side effects in their labeling, and the timing of your symptoms is often the biggest clue.

If your low desire began within weeks of a new prescription, that link deserves a conversation before anyone adds a hormone on top.

Non-hormonal causes worth ruling in or out

Hormones are one input. Desire also depends on mood, sleep, stress, your relationship and what you drink.

How to read your results with a clinician

A single number rarely tells the story. Patterns do. Here is how clinicians typically connect results to next steps.

Result pattern What it can point to Likely next step
Low testosterone on two mornings, high LH and FSH The testes are not producing enough (primary hypogonadism) Discuss treatment options and fertility goals
Low testosterone, low or normal LH and FSH A signaling problem from the pituitary or brain (secondary hypogonadism) The Endocrine Society guideline calls for prolactin, iron studies and pituitary evaluation
Normal total testosterone, abnormal SHBG Free testosterone may be lower or higher than total suggests Let free testosterone guide the decision
Raised prolactin Medication effect, stress of the draw, or a pituitary cause Repeat test, medication review, imaging if it stays high
Abnormal TSH Thyroid disease Treat the thyroid first, then reassess desire
Normal labs, vaginal dryness or pain after menopause Genitourinary syndrome of menopause Discuss local vaginal estrogen

This is where interpretation matters as much as the draw. At BioCure, the Comprehensive Male and Female panels cover hormones, thyroid, lipids, metabolic and organ markers, more than 90 biomarkers in total. A phlebotomist can come to your home, results arrive within 7 to 14 days, and every result is reviewed with a specialist in a 1:1 session. The physician video consultation is $199 and can be credited toward a membership. BioCure does not bill insurance directly, but many patients use HSA or FSA funds and receive documentation for reimbursement. See the full menu on our diagnostics page.

What to do when your labs come back normal

Normal results are not a dead end. They are information. They tell you a hormone prescription is unlikely to be the answer, and the Endocrine Society does not support testosterone therapy for men whose levels are normal. Chasing a higher number without a deficiency adds risk without a clear benefit.

Instead, work the rest of the list. Treat sleep problems. Cut back on alcohol for a month and notice the difference. Get support for mood or stress. Consider couples or sex therapy if relationship dynamics are part of it. If the issue is erections rather than desire, that is a separate problem with its own treatments, and BioCure's sexual health program can evaluate it. Retest if your symptoms change, because hormones shift with age, weight and health over time.

Frequently asked questions

What blood tests should I get for low sex drive?

Men should start with two early morning total testosterone tests, plus free testosterone or SHBG, LH, FSH, prolactin, estradiol, TSH and A1c. Women should check TSH, prolactin, ferritin and a CBC, with FSH and estradiol for perimenopause context. A clinician should read the results alongside your symptoms and medications.

What time of day should I get my testosterone tested?

In the morning, ideally fasting. Testosterone is usually highest early in the day, according to MedlinePlus, and the Endocrine Society recommends confirming a low result with a second morning test before diagnosing low testosterone.

Can a woman's testosterone level explain her low libido?

Not on its own. There is no testosterone cutoff that diagnoses low desire in women, and measured levels do not line up neatly with desire. Labs for women are more useful for finding thyroid, prolactin, iron or menopause-related causes.

Does hormone therapy improve libido if my hormone levels are normal?

The evidence does not support it. The Endocrine Society backs testosterone therapy for men with symptoms and confirmed low levels, not for men with normal levels. For women, The Menopause Society positions hormone therapy as a treatment for menopause symptoms rather than for desire alone.

Can high prolactin cause low sex drive?

Yes. High prolactin suppresses the hormones that drive testosterone and estrogen production, which can lower desire in both men and women. A raised result is usually repeated and followed by a medication review, with pituitary imaging if it stays high.

Can I do hormone testing for low libido at home?

Yes. BioCure Health offers Comprehensive Male and Female panels with an in-home phlebotomist draw, results in 7 to 14 days and a 1:1 review with a specialist. BioCure is licensed in 47 states, and availability in your state is confirmed at intake.

Low desire deserves a real answer, not a guess and not a prescription written before anyone looks at your blood work. Test first, read the pattern with someone who knows what it means, and treat the cause you actually find.

Let BioCure Health lead you in the right direction. Call or text us to schedule an introductory call at 754-206-0838. Your future self will thank you.