The FT3 test (Free Triiodothyronine) measures the amount of the active, unbound form of the thyroid hormone T3 in your blood. Along with FT4 and TSH, it tells your doctor how well your thyroid gland is working — especially when hyperthyroidism (an overactive thyroid) is suspected.
On Healthchecks360 the FT3 test is priced at ₹170, with free home sample collection from NABL-accredited labs. For a complete thyroid picture, most people are better served by the combined profile below.
FT3 test price
| Test | What it includes | Price |
|---|---|---|
| Free Triiodothyronine (FT3) | FT3 only | ₹170 |
| FT3 + FT4 + Ultrasensitive TSH | Full free-hormone thyroid profile | ₹272 |
Prices are indicative starting prices on Healthchecks360 and may change — check the linked test page for the live price.
What is Free T3 and why is it tested?
Triiodothyronine (T3) is the more active of the two main thyroid hormones. Most of it travels bound to proteins; only the small "free" fraction (FT3) is biologically active. Measuring the free form gives a more accurate reading than total T3. Your doctor may order an FT3 test when:
- TSH is low and hyperthyroidism is suspected
- You have symptoms like rapid heartbeat, weight loss, tremors, heat intolerance or anxiety
- They need to confirm "T3 toxicosis" (where FT3 is high but FT4 is normal)
- They are monitoring treatment for an overactive thyroid
FT3 normal range
A commonly used adult reference range for Free T3 is roughly 2.0–4.4 pg/mL (about 3.1–6.8 pmol/L). Reference ranges vary between laboratories and methods, so always read the result against the range printed on your own report.
- High FT3 — often points to hyperthyroidism (e.g. Graves' disease) or T3 toxicosis.
- Low FT3 — can occur in hypothyroidism or during serious non-thyroidal illness.
Because thyroid results work together, FT3 is best interpreted alongside TSH and FT4 — which is why the combined profile is usually the smarter choice.
Preparation & reports
No fasting is required for a thyroid test. If you take thyroid medication, give the sample before your morning dose (or as your doctor advises). Healthchecks360 collects the sample at home and delivers the report digitally, usually within 24 hours.
Frequently asked questions
What is the price of the FT3 test?
The Free T3 (FT3) test is ₹170 on Healthchecks360. The combined FT3 + FT4 + TSH profile is ₹272, with free home sample collection.
What is the normal range for FT3?
Roughly 2.0–4.4 pg/mL (about 3.1–6.8 pmol/L), but ranges vary by lab — check your report's reference range.
Do I need to fast for an FT3 test?
No, fasting is not required for thyroid tests.
Should I get only FT3 or a full thyroid profile?
For most people a full profile (FT3, FT4 and TSH) is more useful, as the three results are interpreted together. FT3 alone is usually ordered to confirm or monitor an overactive thyroid.
Disclaimer: This article is for general information only and is not medical advice. Always consult a qualified doctor to interpret your test results.