What Is a TSH Test? What It Measures and What It Costs

This page explains what the test measures and where to buy it for the least money. It does not say what your number means: that depends on the lab's own reference range and on a clinician who knows your history. The live price for every store we track is on our TSH marker page, and every plan is ranked on the best blood tests page.

What it measures

TSH is made by the pituitary gland, a small gland at the base of the brain, not by the thyroid itself. MedlinePlus describes the loop plainly: "TSH tells your thyroid how much thyroid hormone it needs to make" (MedlinePlus). When thyroid hormone in the blood runs low, the pituitary sends more TSH; when it runs high, the pituitary sends less. So a TSH result is an indirect reading of thyroid output, which is why it is usually the first thyroid test a clinician orders.

Labcorp's own test page puts it in the same terms: the test "measures thyroid stimulating hormone (TSH), which stimulates the thyroid to produce two additional hormones, T4 (thyroxine) and T3 (triiodothyronine)" (Labcorp OnDemand). Quest's store calls its TSH test "often used as a first step in evaluating if the thyroid is functioning properly" (Quest).

What TSH alone cannot do is explain a result. MedlinePlus notes that "a TSH test can't show what is causing a thyroid problem" (MedlinePlus), and that a clinician will often follow an unusual result with free T4, T3 or thyroid antibody tests. If you expect to want those anyway, a thyroid panel bought in one order usually costs less than three separate single tests plus three fees.

A few practical points from the same sources:

• It is a standard blood draw. A vein in the arm, a few minutes at a Quest or Labcorp patient service center.
• Biotin can interfere. Labcorp asks people taking biotin supplements to wait before the draw: "it is recommended that you wait at least 72 hours from your last dose before sample collection" (Labcorp OnDemand).
• Other things move TSH. MedlinePlus lists serious illness, older age and pregnancy among them, and says "Your TSH level may be high or low even when your thyroid gland is healthy" (MedlinePlus).

Why we do not print a range

Each lab sets its own reference range for TSH, and the range on your report is the one that applies to you. MedlinePlus explains that "because labs often use different testing methods, they often use different reference ranges to describe normal results" (MedlinePlus). A number copied from another website can mislead you, so we leave interpretation to your report and your clinician.

Where to get it and what it costs

TSH is sold on its own by every lab-test store we track, and it sits inside nearly every membership and broad panel. The table below shows each store's single-test price, cheapest first, with the fee that store adds per order, and the memberships whose panels include TSH:

List prices from each store's own page. Memberships and panels that include it: Function Health, Superpower, Empirical Health, InsideTracker, Mito Health, Lifeforce, Marek Health, Labs by Hims, Maximus, Everlywell, Quest, Labcorp OnDemand, Ulta Lab Tests, SiPhox Health, Rythm Health, LetsGetChecked.

How to pay the least:

• You want TSH only: a lab-test store. Compare the per-order fee as well as the test price: a store with a low test price and a draw fee can cost more than a store with a slightly higher price and no fee. Our lab test orders price page adds the fees in for you.
• You want TSH with free T4 or a full thyroid panel: buy them in one order at one store, so one fee covers them all. The hormone panels price page lists thyroid and hormone bundles.
• You want a broad yearly panel anyway: a membership that already includes TSH, compared plan by plan on our biomarker coverage table. Function Health starts at $365 a year; Superpower at $199 a year.

Our reviews of Labcorp OnDemand and Ulta Lab Tests cover how ordering, the draw and results work at each. Lab-test stores do not sell in New York, New Jersey or Rhode Island; our guide to ordering your own blood test explains why.

Already have your results?

If you already have a TSH result and want help keeping track of it, LifeFrom, a sister app from the team behind this site, can keep your results in one place and explain them in plain language (LifeFrom). It is our own sister product, not a lab or a clinician, and a clinician is still the person to ask what a result means for you.