Bloodwork, saliva, or urine. What’s the best way to test hormones?

Bloodwork, saliva, and urine testing can provide valuable insights into your body's hormone levels and overall health. These tests can reveal if you have low testosterone, high estrogen, elevated blood sugar, inflammation, or thyroid issues. But why measure hormones at all? Hormones regulate everything from sleep and metabolism to weight and energy. As hormone levels naturally decline with age—especially during menopause—testing is crucial to identify and correct imbalances.

Common Hormone Testing Methods

There are several hormone testing methods available. Understanding their differences helps you choose what’s best for your needs. The four most common types are:

• Blood Serum

• Blood Spot

• Saliva

• Urine

Blood Serum

Blood serum testing is the most common hormone test and is widely taught and understood by doctors. This test involves drawing blood, then spinning it to separate the serum (the liquid portion containing hormones) from blood cells. Serum tests can measure a broad range of hormones including steroid, thyroid, and peptide hormones like LH and FSH.

Patients often go to labs like LabCorp for serum testing, which may require fasting or avoiding medications beforehand to ensure accuracy.

Limitations:
Blood serum tests cannot measure hormones inside tissues, which can differ significantly from serum levels. For example, tissue estrogen can be 10-20 times higher than serum estrogen. Pregnenolone levels mostly reflect adrenal and gonadal activity, not tissue levels, and decline with age. Despite these limitations, serum tests provide useful insights into your hormone status.

Blood Spot

Blood spot testing is popular for at-home hormone testing. It involves pricking a finger to collect drops of blood on a filter card, which are then dried and sent to a lab. This method is stable for shipping and offers excellent correlation with serum tests. Blood spot testing can measure hormones, insulin, blood lipids, vitamin D, thyroid hormones, and minerals like magnesium.

Advantages:

• No needle required

• Convenient home collection

• May be more accurate than serum tests for monitoring topical hormone therapy

Limitations:

• Fewer biomarkers available compared to serum tests (e.g., often missing estrone, estrone sulfate, pregnenolone)

• Does not capture total hormone levels in tissues

Saliva Testing

Saliva testing measures hormones like cortisol, estrogens, progesterone, and androgens from saliva collected at home. Because steroid hormones are mostly bound to proteins in blood and unavailable to tissues, saliva testing measures the bioavailable hormone — the fraction that can affect tissues. This makes saliva testing useful for monitoring hormone therapy and related symptoms.

Limitations:

• Lack of proven reliability for absolute hormone levels

• Best suited for observing cortisol patterns during the day

• Influenced by many external factors

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Urine Testing

Dried urine tests use filter cards saturated with urine and dried for easy shipment. Urine testing excels at measuring hormone metabolites and metabolic pathways, which helps understand hormone metabolism. It is also preferred for testing iodine, heavy metals (arsenic, cadmium), and neurotransmitters.

Advantages:

• Convenient home collection

• Provides detailed information on hormone metabolism and conjugation

Limitations:

• Hormones in urine are mostly metabolized forms and reflect liver activity more than hormone function

• Less effective for measuring actual hormone levels

Which Test Is Best?

For the most reliable and well-researched hormone testing, blood samples (serum or spot) are preferred. Blood tests are also considered the most accurate for monitoring bioidentical hormone replacement therapy.

Why is blood serum testing more common than blood spot?

• Practitioners are more familiar with serum results

• Insurance reimbursement is often easier with serum tests

• Blood spot tests have more limited biomarker options