What's this test for?

This test is ideal if you're experiencing unexplained fatigue, weight loss despite eating normally, rapid heartbeat, or feeling unusually warm. It helps identify hyperthyroidism (overactive thyroid) and a specific condition called T3 toxicosis where only T3 hormone levels are elevated. Many people use this test when they have symptoms of an overactive thyroid but other thyroid tests haven't revealed the full picture.

What happens after I get my results?

You'll receive detailed doctor notes in simple language explaining what your T3 levels mean for your energy, metabolism, and overall health. These notes include personalized recommendations like dietary adjustments, stress management strategies, or whether you should follow up with an endocrinologist for potential medication. You'll also get the standard lab report and can track your thyroid hormone levels over time using our trends feature to monitor how your interventions are working.

What's included in this test?

This test measures Total T3 (Triiodothyronine). This is the active thyroid hormone that directly controls your metabolism, energy production, and body temperature. T3 is essential for diagnosing hyperthyroidism when other thyroid markers appear normal, and it helps explain symptoms like unexplained weight loss, anxiety, rapid heartbeat, or heat intolerance that may not show up on standard thyroid tests.

Who should consider getting this test?

This test is particularly important for people experiencing symptoms of hyperthyroidism like rapid or irregular heartbeat, unexplained weight loss, anxiety, or excessive sweating. It's also recommended if you have fatigue and muscle weakness that isn't explained by other tests, or if you've had abnormal heart rhythms without a clear cause. People already being treated for thyroid conditions may need this test to monitor their treatment effectiveness.

What symptoms indicate I may need this test?

Common symptoms that suggest you may need a T3 test include persistent fatigue combined with unexplained weight loss, feeling unusually warm or sweating excessively, rapid or irregular heartbeat, muscle weakness (especially in your shoulders and thighs), anxiety or nervousness, and difficulty sleeping. You might also experience hand tremors, more frequent bowel movements, or changes in menstrual patterns if you're a woman.

How can I naturally support my thyroid function?

Supporting healthy thyroid function involves ensuring adequate intake of key nutrients like iodine (from seafood, dairy, eggs), selenium (from Brazil nuts, fish, eggs), and zinc (from meat, shellfish, legumes). Managing stress through meditation, yoga, or regular exercise helps balance thyroid hormones. Getting 7-9 hours of quality sleep, limiting processed foods and excess sugar, and avoiding excessive raw cruciferous vegetables (like raw broccoli or kale in large amounts) can also support optimal thyroid health.

What is T3 and why does it matter?

T3 (Triiodothyronine) is the active form of thyroid hormone that directly controls how fast your body uses energy. It's like the gas pedal for your metabolism, affecting your heart rate, body temperature, energy levels, and weight. While TSH and T4 are commonly tested, T3 is the hormone that actually does the work in your cells, making it crucial for diagnosing certain thyroid conditions that other tests might miss.

What does high T3 mean?

High T3 levels typically indicate hyperthyroidism, meaning your thyroid is producing too much hormone and your metabolism is running too fast. This can cause weight loss despite normal eating, rapid heartbeat, anxiety, heat intolerance, and fatigue from your body working in overdrive. Elevated T3 can also occur with certain thyroid nodules, excessive thyroid medication, or rare conditions like T3 toxicosis.

What does low T3 mean?

Low T3 levels may indicate hypothyroidism (underactive thyroid), where your metabolism slows down, leading to fatigue, weight gain, feeling cold, and sluggishness. Low T3 can also result from severe illness, chronic stress, nutritional deficiencies (especially selenium and zinc), or certain medications. Sometimes T3 is low even when other thyroid tests are normal, which is why this specific test can be valuable.

How often should I retest my T3 levels?

If you're being treated for a thyroid condition, your doctor will typically retest every 6-8 weeks after starting or changing medication until your levels stabilize. Once stable, testing every 6-12 months is common for ongoing monitoring. If you're testing for diagnosis and results are abnormal, your doctor may want to retest in 8-12 weeks along with other thyroid markers to confirm the diagnosis and track changes.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

Do you accept health insurance?

Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

T3 Thyroid Test - Fatigue & Metabolism Check

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

[email protected]

Thyroid Test for Fatigue and Unexplained Weight Changes

Tri-iodothyronine (T3) Total

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

What's this test for?

What's included in this test?

What happens after I get my results?

Here’s why 1,000,000+ customers chose us for affordable hassle-free private blood testing.

Thyroid Test for Fatigue and Unexplained Weight Changes

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

1,000,000+ blood tests later, here's what our customers say