You can check your hormone levels through blood tests, saliva samples, or urine collection, depending on which hormones you need measured. A standard blood draw at your doctor’s office is the most common starting point, but each method captures different information. The right choice depends on whether you’re investigating thyroid function, reproductive health, stress hormones, or something else entirely.
Three Ways to Test Your Hormones
Each testing method measures hormones in a fundamentally different way, and that difference matters for accuracy.
Blood (serum) testing is the most widely used method. A standard blood draw measures the total amount of a hormone in your bloodstream, including both the “free” hormones actively working in your body and the ones bound to carrier proteins (essentially inactive). This makes blood testing the gold standard for thyroid hormones and peptide hormones like insulin, which are difficult to measure accurately any other way. The main drawback is that a single blood draw captures only one moment in time, so it can miss the natural rises and falls that happen throughout the day.
Saliva testing measures only the free, unbound hormones floating in your spit. These are the hormones actively available to enter your tissues, which some practitioners consider a more functional picture of what’s happening in your body. Saliva testing really shines for tracking hormones that shift throughout the day, like cortisol. You can collect multiple samples at home over a 24-hour period, something a blood draw can’t easily do. The trade-off: eating or drinking can contaminate the sample, and saliva isn’t reliable for hormones present in very low concentrations.
Urine testing takes yet another angle. Instead of measuring circulating hormones, it looks at hormone metabolites, the byproducts your body creates as it processes and eliminates hormones. Think of it as seeing a “movie” of your hormones rather than a single “photo.” This makes urine testing especially useful for understanding how your body breaks down and clears hormones, offering insight into metabolism and detoxification. The collection process is more involved, though, often requiring you to gather samples over a full day.
Which Hormones Need Which Test
Not every hormone is best measured the same way. Here’s how the major categories break down:
- Thyroid hormones (TSH, Free T3, Free T4): Blood testing is the clear choice. If you’re being screened for thyroid disease, a TSH test alone is often enough as a first step. TSH is the signal your pituitary gland sends to your thyroid, so abnormal levels flag a problem early. If TSH comes back off, your provider will typically add Free T4 (the main thyroid hormone circulating in your blood) and Free T3 (the active form your cells use).
- Cortisol: Saliva testing is ideal for mapping your daily cortisol rhythm. Late-night saliva samples, collected around 11 p.m. on two separate nights, are specifically used to detect conditions like Cushing’s syndrome where cortisol stays abnormally high when it should be at its lowest. Blood cortisol can be unreliable because the stress of having your blood drawn can spike your levels.
- Reproductive hormones (estradiol, progesterone, testosterone, FSH, LH): Blood testing is standard for diagnosis. Saliva can complement this by measuring bioavailable levels of estradiol and progesterone. Urine testing adds detail about how your body metabolizes these hormones.
- Insulin and blood sugar markers: Blood testing only. These peptide hormones can’t be measured accurately in saliva or urine.
Timing Your Test Correctly
Hormone levels aren’t static. They fluctuate by time of day, day of your menstrual cycle, and even by what you ate that morning. Testing at the wrong time can produce results that look abnormal when they’re perfectly fine, or normal when something is actually off.
For reproductive hormones, timing around your menstrual cycle is critical. FSH and estradiol are typically drawn on day 2, 3, or 4 of your cycle (counting from the first day of your period). This baseline reading reveals your ovarian reserve, essentially how hard your body is working to stimulate egg development. A low FSH alongside a low estradiol at this point suggests healthy reserve. If estradiol is already elevated on day 3, it can artificially push FSH into the normal range and mask a real problem.
Testosterone is best measured in the morning, when levels peak. For adult men, the typical reference range for total testosterone is 249 to 836 ng/dL for those aged 19 to 49, dropping slightly to 193 to 740 ng/dL after age 50. Free testosterone (the portion not bound to proteins) runs between 32 and 168 pg/mL for adult men 18 and older. Testing in the afternoon, when testosterone naturally dips, could produce a falsely low result.
Cortisol follows a predictable daily curve, peaking in the early morning and bottoming out late at night. Depending on what your provider is looking for, you may need a morning blood draw, a late-night saliva sample, or both.
Medications and Supplements That Skew Results
Several common medications and supplements can interfere with hormone test accuracy, and you may not think to mention them unless asked.
Biotin is a major one. High-dose biotin supplements (5 mg or more per day), widely marketed for hair, skin, and nail health, can interfere with the immunoassay technology used in many hormone tests. The effect isn’t subtle: biotin can make testosterone results appear falsely high and sex hormone-binding globulin (SHBG) appear falsely low. If you’re taking biotin at doses of 5 mg or higher, stop it at least one week before your blood draw.
Steroids like prednisone and prednisolone will produce falsely elevated cortisol readings. DHEA supplements, popular in anti-aging circles, can inflate progesterone results. If you’re on any medications or supplements, let your provider know before testing so they can adjust the timing or interpretation.
At-Home Hormone Test Kits
At-home hormone kits have exploded in popularity. Most use a finger-prick blood sample or saliva collection that you mail to a lab. While convenient, their reliability varies significantly depending on what you’re testing.
At-home menopause tests, which typically measure FSH in urine, are a good example of where these kits fall short. FSH levels vary considerably from person to person and fluctuate throughout the menstrual cycle, making a single at-home reading unreliable for determining menopausal status. As researchers at the University of Utah Health have pointed out, these results are difficult to interpret and shouldn’t be relied on for accuracy. If you’re 45 or older and experiencing symptoms like irregular periods and hot flashes, testing usually isn’t even necessary, since elevated FSH is simply a normal part of the transition.
Bloodwork ordered through a healthcare provider gives more precise measurements and can identify underlying conditions that an at-home kit would miss entirely. If you do use an at-home kit, treat the results as a starting point for a conversation with your doctor, not a diagnosis.
Why Lab Method Matters
Not all labs process your sample the same way. Traditional hormone testing uses a technology called immunoassay, which works well for most situations but has known weaknesses. It can produce inaccurate results at very low or very high hormone concentrations and is prone to cross-reactivity, where structurally similar compounds in your blood get mistakenly counted as the hormone being tested.
A newer method called liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers significantly better precision. It’s particularly superior for measuring low-concentration hormones like testosterone in women or children, and progesterone. Studies comparing the two methods show they generally correlate well overall, but LC-MS/MS delivers notably better accuracy at the low end of the range, exactly where errors matter most for diagnosis. If your results are borderline or don’t match your symptoms, it’s worth asking your provider whether the lab used immunoassay or LC-MS/MS.
Getting Started With Testing
If you have specific symptoms, your primary care doctor can order the relevant hormone panel. For fatigue, weight changes, or cold sensitivity, that typically means thyroid testing. For irregular periods, fertility concerns, or menopausal symptoms, expect a reproductive hormone panel. For chronic fatigue, sleep disruption, or stress-related symptoms, cortisol testing is the logical starting point.
You don’t necessarily need a massive panel covering every hormone in your body. Targeted testing based on your symptoms is more useful and easier to interpret than a scattershot approach. A few well-chosen tests, drawn at the right time and processed by a reliable lab, will tell you far more than a dozen poorly timed ones.