Your doctor checks TSH and calls it a day. That misses conversion issues (T4 to T3), reverse T3 blocking, and autoimmune thyroid disease, the three most common reasons people feel terrible despite "normal" thyroid labs. This panel checks everything: TSH, Free T3, Free T4, Reverse T3, TPO Antibodies, and Thyroglobulin Antibodies. Atlas AI scores your thyroid function as a complete system, not a single number.
The Thyroid Complete panel tests eight markers from one blood draw, TSH, Free T3, Free T4, Reverse T3, the T3/RT3 ratio, TPO antibodies, thyroglobulin antibodies and thyroglobulin. It is built for adults who want to see thyroid signalling, active hormone, hormone conversion and autoimmune activity together rather than relying on a single screening number.
This page is educational and is not medical advice.
It measures eight biomarkers across two groups, five that describe thyroid hormone signalling and conversion, and three that describe autoimmune activity and thyroid protein output.
| Group | Marker | What it shows |
|---|---|---|
| Thyroid hormones | TSH | The pituitary signal that tells the thyroid how hard to work. It tends to rise when the brain senses too little thyroid hormone and fall when it senses too much. |
| Thyroid hormones | Free T3 | The unbound, biologically active hormone that enters cells and sets metabolic pace. |
| Thyroid hormones | Free T4 | The unbound storage form the thyroid releases most of, and the raw material the body converts into T3. |
| Thyroid hormones | Reverse T3 | An inactive form produced when T4 is diverted away from the active pathway, often during illness, under-eating or heavy physiological stress. |
| Thyroid hormones | T3/RT3 Ratio | A calculated comparison of active to inactive hormone, used to look at how conversion is running rather than hormone quantity alone. |
| Thyroid antibodies | TPO Antibodies | Antibodies directed at thyroid peroxidase, the enzyme used in hormone production, and the most commonly measured marker of autoimmune thyroid activity. |
| Thyroid antibodies | Thyroglobulin Antibodies | Antibodies directed at thyroglobulin, measured alongside TPO antibodies to widen the autoimmune picture and to flag possible interference in thyroglobulin testing. |
| Thyroid antibodies | Thyroglobulin | The protein the thyroid uses to build hormone, measured as a marker of thyroid tissue activity. |
Reference ranges for each marker are printed on your lab report, and they vary by laboratory, assay, age and sex.
Because each marker reports a different link in the same chain, and one value can look reassuring while another is already moving.
TSH is a pituitary signal rather than a direct measure of thyroid hormone, so it answers the question of how hard the brain is pushing the gland. A raised TSH with free hormone still inside the standard range is the pattern labs regard as subclinical hypothyroidism, which research describes as a laboratory finding rather than a symptom checklist 1. A low or suppressed TSH points the other way, and research on hyperthyroidism describes it as the usual first laboratory clue, with free hormone measurement used to characterise it 2.
Free T4 shows what the gland is actually releasing, and Free T3 shows how much active hormone is available to tissue. Those two can separate. Reverse T3 and the T3/RT3 ratio add the conversion angle, because T4 can be routed toward the inactive form instead of the active one. Studies indicate that non-thyroidal illness, calorie restriction and acute stress shift this conversion pattern, which is one reason a single value drawn during an unwell week may not represent a baseline 3.
The antibody markers answer a different question, whether the immune system is involved. TPO Antibodies and Thyroglobulin Antibodies are associated with autoimmune thyroid activity, and antibody positivity can be present while hormone levels still sit inside standard ranges. Thyroglobulin antibodies also matter technically, since their presence is associated with interference in thyroglobulin measurement, so the two are interpreted side by side 3.
Adults looking into persistent symptoms, a family history of thyroid conditions, or a fuller baseline than a single TSH often consider a panel like this one.
Common reasons people want a wider view include fatigue that does not resolve with sleep, unexplained weight change, cold or heat sensitivity, hair thinning, dry skin, low mood, brain fog, cycle changes or a resting heart rate that has drifted. None of these symptoms confirms a thyroid condition on its own, and many have other explanations, which is exactly why measurement is more useful than guesswork.
Family history matters because autoimmune thyroid conditions cluster in families, and antibodies can appear before hormone levels change. Life stage matters too. Postpartum thyroid inflammation is a recognised condition in the year after birth, and research describes a course that can include both overactive and underactive phases 5. Thyroid status is also part of the workup discussed in guidance on recurrent miscarriage, where thyroid antibodies and thyroid function are considered during investigation 6. In older adults, research suggests the presentation of thyroid overactivity can be quieter and less typical than in younger people 7.
Thyroid status is also linked to cardiovascular physiology. Research describes consistent associations between thyroid hormone levels and heart rate, cardiac output and vascular resistance, which is why thyroid markers are often reviewed alongside cardiovascular markers 4. Having the numbers gives a clinician something concrete to work from.
You order the panel online, FitScript emails your requisition, and you take it to a Quest or partner lab location for a standard blood draw.
No fasting is required for this panel. Appointments are available at lab locations nationwide, and the draw itself is a single venous sample. Results are typically returned in 3-5 business days, and they are posted to your account as soon as the lab releases them.
Atlas, FitScript's AI health advisor, then reads every marker against optimal ranges and explains what each value shows in the context of the others, so you are not left holding a sheet of numbers without a narrative. Add-on panels can be run from the same sample, which avoids a second visit if you decide to widen the picture at the point of ordering.
Keep it simple, stay hydrated, book a consistent time of day, and keep taking any prescribed medication unless your clinician tells you otherwise.
Fasting is not needed. Drinking water before the draw makes the blood draw easier. Timing is worth some thought, since TSH follows a daily rhythm and tends to be higher in the early morning, so drawing at a similar time each round makes results easier to compare across tests.
Supplements deserve attention. High-dose biotin, found in many hair, skin and nail products, can interfere with the immunoassays used for thyroid markers and shift results in either direction, and research on laboratory pitfalls describes this as a recognised source of misleading values 3. Many clinicians ask people to pause biotin before a thyroid draw, and your clinician can tell you whether and for how long. Iodine intake also matters, since research describes both deficiency and excess iodine exposure as influences on thyroid function, including from iodine-containing supplements and contrast agents 8.
Do not stop thyroid medication, mood-stabilising or heart rhythm medicines, steroids or any other prescription before a test on your own. The point of the panel is to measure your real-world state, and a licensed provider decides whether anything should change.
Read each value twice, once against the laboratory's standard reference range and once against the optimal range, then read the markers as a set rather than one at a time.
A standard reference range describes where most results in a reference population fall, and it is built for detecting disease. An optimal range is narrower and is used as an optimization target, not a diagnostic cut-off. A value inside the standard range but outside the optimal range is best described as suboptimal, not abnormal, and it is a prompt for a conversation rather than a conclusion.
The useful sequence is observation, then meaning, then next step. A raised TSH with free hormone inside range is an observation. It may reflect early reduced thyroid output, recovery from illness, assay interference or normal variation, and research on subclinical hypothyroidism emphasises repeat measurement before any conclusion is drawn 1. The next step is to discuss it with a clinician, who can decide whether a repeat draw, antibody context or further testing is appropriate.
One result is a snapshot. Thyroid markers move with illness, sleep debt, aggressive dieting, pregnancy and medication, so a single out-of-range value is a starting point. Retesting intervals are set by your clinician, and levels need time to settle after any change before a repeat draw is meaningful. FitScript membership covers 150+ biomarkers tested per year, which makes serial comparison easier than one-off testing. Always discuss your results, and any treatment decision, with a clinician or licensed provider. Any prescription therapy for thyroid conditions is something a licensed provider evaluates for appropriateness after reviewing you, your history and your labs.
It cannot diagnose a thyroid condition, and it cannot see the gland itself.
Blood markers describe hormone signalling and immune activity. They do not show nodules, goitre, inflammation visible on imaging or structural change, which is what thyroid ultrasound is for. They do not show how a gland takes up iodine, which is what a nuclear medicine uptake study assesses, and research on hyperthyroidism describes imaging and uptake testing as part of working out the cause once bloods suggest overactivity 2.
The panel also does not measure iodine status, selenium, iron, ferritin or cortisol, all of which sit around thyroid physiology. It does not assess pituitary imaging, and rare central causes of abnormal results need a clinician's workup. Assay interference, biotin, antibodies and unusual binding proteins can all distort results, which is why laboratory guidance stresses interpreting numbers in clinical context rather than in isolation 3. A diagnosis is made by a clinician who combines labs, history, examination and, where needed, imaging.
This panel goes deep on one system, while the other panels either extend it or broaden the baseline.
The Thyroid Plus Add-On extends thyroid testing further and runs from the same sample when ordered together, which suits people who already know thyroid is their question. FitScript Essential is the broad baseline across multiple systems, which suits people who want a general picture first and may narrow down later. Neither replaces the other. Depth and breadth answer different questions, and which one fits depends on what you are trying to find out.
The Thyroid Complete panel costs $149, and it is HSA/FSA eligible.
That covers the eight markers listed above, the lab draw at a Quest or partner location, and interpretation by Atlas against optimal ranges. Add-on panels ordered at the same time run from the same blood sample, so you only sit for one draw.
TSH is a pituitary signal, not a thyroid hormone. It can be "normal" while Free T3 is low (your body isn't converting T4 to T3), Reverse T3 is high (blocking your T3 receptors), or TPO antibodies are elevated (your immune system is attacking your thyroid). All four patterns cause hypothyroid symptoms with normal TSH.
Reverse T3 is an inactive form of thyroid hormone that competes with active T3 for receptor sites. When elevated, common during chronic stress, inflammation, or caloric restriction, it effectively blocks thyroid function even when TSH and T4 look normal. The T3/RT3 ratio is the key metric.
Elevated TPO or thyroglobulin antibodies indicate your immune system is targeting your thyroid gland, this is Hashimoto's thyroiditis, the most common cause of hypothyroidism. Antibodies can be elevated for years before TSH becomes abnormal, making early detection critical for intervention.
No fasting required. If you take thyroid medication (levothyroxine, Synthroid, Armour), draw blood before your morning dose. Taking it beforehand will artificially spike Free T4 and give inaccurate results.
A complete thyroid blood test measures thyroid signalling, circulating hormone, hormone conversion and autoimmune activity in one draw rather than a single screening value. The Thyroid Complete panel covers TSH, Free T3, Free T4, Reverse T3, the T3/RT3 ratio, TPO antibodies, thyroglobulin antibodies and thyroglobulin, giving a clinician a pattern to interpret.
A thyroid panel with antibodies adds immune markers to the hormone markers. TPO antibodies and thyroglobulin antibodies are associated with autoimmune thyroid activity and can be present while hormone levels still sit inside standard ranges. They also flag possible interference in thyroglobulin testing, so results are interpreted together by a clinician.
A full thyroid panel includes both hormone and antibody markers. The Thyroid Complete panel includes TSH, Free T3, Free T4, Reverse T3 and the calculated T3/RT3 ratio in the hormone group, plus TPO antibodies, thyroglobulin antibodies and thyroglobulin in the antibody group, for eight markers from a single blood sample.
No fasting is required for the Thyroid Complete panel. Drink water beforehand so the draw goes smoothly. Because TSH follows a daily rhythm and tends to be higher early in the morning, booking a similar time of day for each round makes results easier to compare over time.
Yes, high-dose biotin can interfere with the immunoassays used for thyroid markers and shift values in either direction, a recognised source of misleading results. Biotin is common in hair, skin and nail products. Ask your clinician whether to pause it before testing and for how long.
No. Keep taking any prescribed medication unless your clinician specifically tells you otherwise. The panel is meant to capture your real-world state, and stopping medication on your own changes what the numbers mean. A licensed provider decides whether any dose or therapy should change after reviewing your results.
Results are typically available in 3-5 business days after your draw at a Quest or partner lab location. Atlas, FitScript's AI health advisor, reads every marker against optimal ranges and explains how the values relate to each other. A clinician interprets your results in full clinical context.
No. The panel measures biomarkers, it does not diagnose. Blood markers cannot show nodules, goitre or structural change, which may require ultrasound or other testing. A result outside the standard range is worth discussing with a clinician promptly, who combines labs, history, examination and imaging where needed.
The Thyroid Complete panel costs $149 and it is HSA/FSA eligible. That covers the eight markers, the draw at a Quest or partner lab location, and interpretation by Atlas against optimal ranges. Add-on panels ordered at the same time run from the same blood sample, so only one draw is needed.