It is a focused look at how your thyroid axis is working and whether autoimmunity is present. Superpower tests your blood for: TSH ↑, Free T4 Index ↓, T4 Total ↓, T3 Uptake ↓, TPO Ab, Tg Ab. TSH shows pituitary drive; Free T4 Index and Total T4 reflect circulating hormone; T3 Uptake tracks binding-protein effects and feeds the Free T4 Index; TPO and Tg antibodies detect Hashimoto’s thyroiditis. Together, these markers show whether hormone production is low (primary hypothyroidism), borderline (subclinical), or affected by protein binding or central regulation.

Symptoms overlap with many conditions, and exam alone can’t confirm underactive thyroid. This panel objectively checks hormone production (TSH, Free T4 Index, Total T4), separates true thyroid deficiency from binding-protein shifts (T3 Uptake/Free T4 Index), and identifies autoimmune thyroiditis (TPO Ab, Tg Ab), the most common cause. It helps explain fatigue, weight gain, cold intolerance, constipation, hair loss, menstrual changes, or high cholesterol. It also guides monitoring if you’re on thyroid medication, have positive antibodies, a goiter, prior neck radiation, take interfering drugs, or are planning pregnancy.

Yes. With Superpower, our team member can organise blood draw in your home. We schedule a licensed phlebotomist, handle transport to the lab, and return results in your dashboard with clear explanations of TSH, Free T4 Index, Total T4, T3 Uptake, TPO Ab, and Tg Ab.

If starting or changing thyroid medication, retest in 6–8 weeks (steady-state). If stable on therapy, check every 6–12 months. With elevated TSH but normal T4 (subclinical), repeat in 3–6 months and then periodically. If TPO or Tg antibodies are positive, monitor at least annually to track progression risk. In pregnancy or planning pregnancy, test preconception and once per trimester. After exposure to iodine load, amiodarone, lithium, or pituitary disease, test based on clinical change. Recheck sooner if symptoms shift or major illness occurs.

High-dose biotin can falsely lower TSH and raise T4 measurements on many assays. Estrogen or pregnancy increases TBG, lowering T3 Uptake and raising Total T4 while Free T4 Index remains the truer gauge. Androgens do the opposite. Amiodarone, lithium, glucocorticoids, dopamine, heparin, and some anti-seizure drugs alter thyroid tests. Severe illness (non-thyroidal illness), recent iodinated contrast, and acute psychiatric or critical stress can distort TSH/thyroid hormone levels. Time of day matters (TSH peaks overnight). Age, postpartum status, and weight changes also shift set-points. Autoantibodies can rarely interfere with certain immunoassays.

No fasting is required. Aim for a morning draw for consistent TSH. Stop high-dose biotin for 48–72 hours before testing. If you take levothyroxine, take it after the blood draw to avoid post-dose peaks; test at least 6 weeks after any dose change. Tell us about estrogen therapy, amiodarone, lithium, steroids, anti-seizure meds, or recent iodinated contrast. Avoid testing during acute severe illness if possible. Pregnancy status should be noted because binding proteins change interpretation.

Only modestly. Very high or very low iodine intake can shift thyroid hormone levels. Severe calorie restriction, intense systemic illness, and major stress can suppress T3 and alter TSH. Smoking and some supplements (notably biotin and “thyroid support” products) can distort results. Typical exercise and balanced diets have minimal direct impact on TSH or Free T4 Index. If antibodies are positive, lifestyle won’t remove them, but overall metabolic stress can influence the thyroid set-point.

Primary hypothyroidism shows TSH high with Free T4 Index and Total T4 low; T3 Uptake may be low, especially with high binding proteins. Subclinical hypothyroidism shows TSH high with normal Free T4 Index/Total T4; positive TPO or Tg antibodies increase progression risk. Autoimmune thyroiditis is supported by positive TPO Ab and/or Tg Ab regardless of current hormone levels. Central (pituitary) hypothyroidism shows low or inappropriately normal TSH with low Free T4 Index. If T3 Uptake is low but Free T4 Index is normal, think binding-protein effects rather than true hormone deficiency. We integrate all markers, not one alone.