
Biological age
Find out if your body is aging faster or slower than your actual age — and see how you rank against the general population.
39
Biological age
44
Actual age
4.2
Years younger

TSH (Thyroid-Stimulating Hormone) Test. A TSH test checks how strongly your pituitary is signaling your thyroid and helps interpret hypo- or hyperthyroid patterns, with convenient Quest lab access via Vitals Vault.
TSH (thyroid-stimulating hormone) is often the first lab test used to check whether your thyroid system is running “too slow” or “too fast.” Even though it is called a thyroid test, TSH is made by your pituitary gland and acts like a thermostat signal to your thyroid. A single TSH result can be very informative, but it is easiest to interpret when you look at it alongside your symptoms, your medications, and often a few companion thyroid labs (like free T4). If you are already on thyroid medication, TSH is also one of the main ways dosing is monitored over time. Because reference ranges vary by lab and your “best” level depends on context, the goal is not to self-diagnose from one number. The goal is to use TSH to guide a clinician-directed plan and decide whether follow-up testing or a retest makes sense.
What to expect before and at your draw.
Sample Type
Blood
Collection Method
In person at a Quest Diagnostics location
Age
18+
This order includes the lab markers used for TSH.
Tsh
Included in this Quest Diagnostics order and reported in your Vitals Vault account.
Order TSH online.
Visit a Quest Diagnostics location near you for your blood draw. Appointments can be scheduled after checkout.
View easy-to-read results in your Vitals Vault account, with trends and clinician-guided follow-up when available.
Included with every package
Function Health shows you numbers. Vitals Vault connects them — ratios, patterns, and a personalized action plan grounded in functional medicine.

Find out if your body is aging faster or slower than your actual age — and see how you rank against the general population.
39
Biological age
44
Actual age
4.2
Years younger

Turn lab data into what to do next—clear guidance on follow-ups, lifestyle context, and add-on testing when you need to go deeper. Make the healthy choice the obvious one.

A personalized, plain-language walkthrough of your abnormal markers—reference ranges, pattern context, and what to watch next, grounded in your actual labs.
Personalized Insights
Clear Explanations
Actionable guidance

Explore your body systems with clear risk context — refresh your report, download the full PDF, and monitor hormones, heart, bone, and more in one place.

Explore hundreds of tests and panels, filter by concern, and manage your cart—member-exclusive pricing with quick checks and full-body options in one flow.
Wide test selection
300+ tests & panels available
Smart filtering
Find tests by symptoms or goals
Seamless ordering
Add to cart and manage easily

Upload past lab reports, search your documents, and keep appointments and results organized—our AI can extract biomarkers from PDFs so everything lives in one dashboard.

Browse longevity, nutrition, supplement, and movement protocols—structured plans you can follow with clear habits, labs, and targets tied to your profile.

Ask for protocols, nutrition plans, supplement stacks, and education—context-aware suggestions powered by your labs and goals (beta experience).
Customer feedback
—
No reviews yet
Be the first to rate this test. Your feedback helps others decide with confidence.
Order online
Add TSH to your cart and check out. No doctor referral is required.
Visit a Quest lab
Provide your blood sample at a Quest Diagnostics location. Appointments can be scheduled after checkout.
Review in Vitals Vault
Results typically arrive in about a week and stay in your Vitals Vault account for trends and follow-up.
No special preparation is usually needed unless noted at checkout.
This order includes the lab markers used for TSH and reported in your Vitals Vault account.
Results
About 1 week after your draw
HSA/FSA
Accepted
Who takes it
Must be taken by the purchaser
Preparation
No special preparation needed unless noted at checkout.
A TSH test checks how strongly your pituitary is signaling your thyroid and helps interpret hypo- or hyperthyroid patterns, with convenient Quest lab access via Vitals Vault.
TSH (thyroid-stimulating hormone) is often the first lab test used to check whether your thyroid system is running “too slow” or “too fast.” Even though it is called a thyroid test, TSH is made by your pituitary gland and acts like a thermostat signal to your thyroid.
A single TSH result can be very informative, but it is easiest to interpret when you look at it alongside your symptoms, your medications, and often a few companion thyroid labs (like free T4). If you are already on thyroid medication, TSH is also one of the main ways dosing is monitored over time.
Because reference ranges vary by lab and your “best” level depends on context, the goal is not to self-diagnose from one number. The goal is to use TSH to guide a clinician-directed plan and decide whether follow-up testing or a retest makes sense.
You might consider a TSH test if you have symptoms that could fit a thyroid pattern, especially when they are persistent or unexplained. Common reasons include fatigue that does not improve with sleep, feeling unusually cold or hot, constipation or frequent bowel movements, hair thinning, dry skin, palpitations, anxiety, low mood, or unintentional weight change.
TSH testing is also common when you are evaluating cholesterol changes, irregular periods, fertility concerns, or postpartum symptoms, because thyroid signaling can affect metabolism and reproductive hormones. If you are pregnant or planning pregnancy, your clinician may use TSH (often with free T4) because thyroid needs can shift and target ranges may be different.
If you already take thyroid medication (such as levothyroxine) or you have a history of thyroid disease, TSH is one of the standard tests used to monitor whether your current dose is likely too low, too high, or stable. It can also help clarify whether symptoms are more likely thyroid-related or whether another cause should be investigated.
Testing supports clinician-directed care, but it cannot diagnose the cause of symptoms by itself. When TSH is abnormal, follow-up labs and your clinical history usually determine what the result actually means for you.
TSH is measured on validated clinical laboratory immunoassays; results should be interpreted with your clinician and are not a standalone diagnosis.
Lab testing
from $19.99 at Quest Diagnostics
About 1 week
Schedule online — results typically within a week
Clear next steps
Guidance included, with follow-up care available
HSA / FSA
Eligible for pre-tax health spending accounts
Vitals Vault lets you order a TSH test (or a broader thyroid panel) without needing a separate referral visit, and you can choose a nearby Quest location for your blood draw. This is helpful when you want a baseline, you are monitoring a known thyroid condition, or you and your clinician want updated data before making changes.
After your results post, PocketMD can help you translate the number into plain language and generate a focused set of questions to bring to your next appointment. If your TSH is out of range, PocketMD can also suggest common companion labs to discuss (like free T4, free T3, and thyroid antibodies) so you are not guessing at next steps.
If you are tracking trends, you can recheck TSH at an appropriate interval and keep your results organized in one place. That makes it easier to see whether a change is a one-time fluctuation or a consistent pattern worth acting on.
TSH stands for thyroid-stimulating hormone. It is produced by your pituitary gland in the brain and released into your bloodstream to tell your thyroid gland how much thyroid hormone to make.
Your thyroid mainly produces thyroxine (T4), which is converted in tissues to triiodothyronine (T3), the more active form. When your body senses that thyroid hormone levels are low, your pituitary typically raises TSH to push the thyroid to produce more. When thyroid hormone levels are high, your pituitary usually lowers TSH.
Because of this feedback loop, TSH often moves in the opposite direction of thyroid hormone levels. That is why a “thyroid problem” can show up first as an abnormal TSH even when T4 and T3 are still within range.
TSH is a powerful screening tool, but it does not tell the whole story. The same TSH value can mean different things depending on whether you are pregnant, taking thyroid medication, recovering from illness, or have pituitary or hypothalamic conditions that affect signaling.
TSH is the signal; free T4 and free T3 reflect circulating thyroid hormone available to your tissues. If TSH is abnormal, checking free T4 (and sometimes free T3) helps confirm whether your body is actually seeing too little or too much thyroid hormone.
Most thyroid disorders are “primary,” meaning the thyroid gland is the main issue. In primary hypothyroidism, TSH is typically high because the pituitary is trying to stimulate a sluggish thyroid. In central (pituitary or hypothalamic) hypothyroidism, TSH may be low or in-range even when free T4 is low, because the signal itself is impaired.
A low TSH often means your pituitary is dialing down the signal because your body is experiencing a higher thyroid hormone effect. This pattern can be seen with hyperthyroidism, thyroid hormone over-replacement (dose too high), or transient thyroid inflammation. If your TSH is low, your clinician commonly checks free T4 and sometimes free T3 to see whether thyroid hormone levels are actually elevated and how urgent follow-up should be.
An in-range TSH usually suggests your pituitary-thyroid feedback loop is working in a typical way at the time of testing. If you still have symptoms, it does not automatically rule out thyroid-related issues, because early disease, medication timing, pregnancy targets, or central thyroid problems can complicate interpretation. Trending your TSH and pairing it with free T4 (and antibodies when appropriate) can add clarity when the picture is not straightforward.
Clinical graph note: the optimal range is narrower than the standard lab range. Standard range: 0.40 - 4.50 mIU/L. Optimal range: 1.00 - 2.00 mIU/L.
A high TSH often means your pituitary is pushing harder because your body is experiencing a lower thyroid hormone effect. This pattern is common in hypothyroidism, including autoimmune thyroid disease (Hashimoto’s), and it can also occur if thyroid medication dosing is too low or doses are missed. Your clinician will usually look at free T4 to distinguish subclinical hypothyroidism (TSH high, free T4 normal) from overt hypothyroidism (TSH high, free T4 low), since management can differ.
TSH can vary with time of day (often higher overnight and early morning), recent illness, and major changes in sleep or stress. Pregnancy, postpartum changes, and aging can shift expected ranges and treatment targets. Medications and supplements can also affect results, including thyroid hormone, antithyroid drugs, amiodarone, lithium, high-dose biotin, and some steroids or dopamine-related medicines. If you are monitoring treatment, consistency matters: try to test at a similar time of day and discuss how to time thyroid medication relative to the blood draw.
A “normal” TSH range depends on the lab method and the reference interval printed on your report, and it can also depend on life stage (especially pregnancy). Many labs use a general adult reference range, but your clinician may use different targets if you are pregnant, trying to conceive, older, or on thyroid medication.
Fasting is not usually required for TSH. However, consistency helps if you are trending results, so try to test at a similar time of day and tell your clinician about any supplements (especially biotin) or thyroid medications that could affect interpretation.
TSH responds gradually to dose changes, so clinicians commonly recheck it after several weeks rather than a few days. The right timing depends on your situation and medication type, but a typical approach is to retest once levels have had time to reach a new steady state.
Yes. Acute illness, recovery from illness, major sleep disruption, and significant stress can shift thyroid signaling temporarily. If your result is mildly abnormal and you were recently sick, your clinician may recommend repeating TSH (often with free T4) once you are back to baseline.
Common companion tests include free T4 and sometimes free T3 to confirm the hormone pattern. If autoimmune thyroid disease is a concern, thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb) are often used. Your clinician may also consider a thyroid ultrasound or other evaluation depending on symptoms and exam findings.
This can happen in subclinical thyroid dysfunction, early thyroid disease, or during recovery from illness. It can also occur if your body is adjusting to medication changes or if there are factors affecting the pituitary-thyroid feedback loop. Your clinician may recommend trending labs, checking antibodies, and matching results to symptoms before deciding on treatment.
Purchase online through Vitals Vault. A licensed clinician reviews and approves your order, then you receive a digital requisition for a Quest Diagnostics blood draw.
Samples are collected in person at Quest Diagnostics locations nationwide. After checkout you can schedule your visit at a convenient site.
Most results are ready about a week after your draw. You can view them securely in your Vitals Vault account.
No separate referral appointment is required. Clinician review is included in the online order flow.
Yes. Eligible HSA/FSA cards can be used at checkout for qualifying lab orders.
Results are available in your secure Vitals Vault account. You control who you share them with, subject to applicable law.
Blood glucose shows the amount of sugar in your blood at a single moment. A1c (hemoglobin A1c) estimates your average blood sugar over roughly the past 8–12 weeks. Comparing them helps explain whether your long-term average lines up with your fasting glucose on draw day.
It helps you understand how this marker fits into your broader metabolic picture, with results tracked in your Vitals Vault account.
Elevated values can signal higher metabolic risk. Many people start with nutrition, activity, sleep, and weight management, then retest and review results with a clinician. This test is educational and does not replace medical advice or diagnosis.
Your sample is processed at CLIA-certified Quest Diagnostics laboratories. Results should still be interpreted with a qualified clinician alongside your history, symptoms, and other labs.
Consumer-initiated testing through Vitals Vault is limited to adults 18+ so ordering and interpretation stay aligned with clinical best practices for this channel.