What's this test for?

This test is ideal if you're experiencing constant tiredness, weakness, pale skin, or shortness of breath that might be caused by iron deficiency. It helps identify if your body has enough iron available for your cells to function properly, which is essential for energy production and carrying oxygen throughout your body. Many people use this test when they suspect iron deficiency but want to confirm it before starting supplements or making dietary changes.

What happens after I get my results?

You'll receive detailed doctor notes in simple language explaining what your iron status means for your energy levels and overall health. These notes include personalized recommendations like dietary changes to increase iron absorption, supplement suggestions, or whether you should investigate potential causes of iron loss. You'll also get the standard lab report and can track your iron levels over time using our trends feature to see how your diet and supplement interventions are working.

What's included in this test?

This test measures Soluble Transferrin Receptor (sTFR). This test measures Soluble Transferrin Receptor (sTFR), which is a specialized marker that detects functional iron deficiency at the cellular level. Unlike standard iron tests, sTFR levels rise only when your cells aren't getting enough iron to work properly, making it especially useful for identifying true iron deficiency even when other conditions are present. This measurement provides clear insight into whether tiredness and fatigue are related to inadequate iron availability for your body's essential functions.

Who should consider getting this test?

This test is particularly valuable for people with chronic diseases, athletes with unexplained fatigue, pregnant women, frequent blood donors, and anyone living at high altitudes. It's also helpful if previous iron tests were unclear or if you have symptoms of iron deficiency but standard tests came back normal. People with inflammatory conditions may especially benefit since this test isn't affected by inflammation like other iron markers.

What symptoms indicate I may need this test?

Common symptoms of iron deficiency include persistent tiredness even after rest, weakness, pale or yellowish skin, cold hands and feet, brittle nails, and frequent headaches. You might also notice shortness of breath during normal activities, difficulty concentrating or brain fog, rapid heartbeat, or unusual cravings for non-food items like ice or dirt. If you experience several of these symptoms together, checking your iron status can help identify the cause.

How can I naturally support my iron levels?

Boost your iron intake by eating red meat, poultry, fish, beans, lentils, tofu, and dark leafy greens like spinach. Pair iron-rich foods with vitamin C sources like citrus fruits, tomatoes, or bell peppers to enhance absorption. Avoid drinking tea or coffee with meals since they can block iron absorption, and consider cooking in cast iron cookware which adds small amounts of iron to food. If you're vegetarian or vegan, focus on eating a variety of plant-based iron sources throughout the day.

What is Soluble Transferrin Receptor and why does it matter?

Soluble Transferrin Receptor (sTFR) is a protein that increases when your body's cells need more iron but aren't getting it. Think of it as your cells sending out more receivers to catch whatever iron is available in your blood. When sTFR levels are elevated, it indicates functional iron deficiency, meaning your cells are literally starved for iron even if your iron storage levels look normal on other tests. This makes it one of the most accurate ways to detect true iron deficiency.

What does high Soluble Transferrin Receptor mean?

High sTFR levels indicate that your body's cells aren't getting enough iron to function properly, which is called functional iron deficiency. This can happen even if your iron storage looks normal, and it explains symptoms like fatigue, weakness, and reduced physical performance. Elevated levels are commonly seen in people with true iron deficiency anemia, during pregnancy, at high altitudes, and in athletes with increased iron demands.

What causes high Soluble Transferrin Receptor levels?

The most common cause is inadequate iron intake through diet or poor iron absorption from conditions like celiac disease or inflammatory bowel disease. Ongoing blood loss from heavy menstrual periods, gastrointestinal bleeding, or frequent blood donation can also deplete iron stores. Pregnancy increases iron demands significantly, and intense athletic training can increase iron needs while also causing small amounts of iron loss through sweat and muscle breakdown.

How often should I retest my iron levels?

If you're starting iron supplements or making dietary changes, retest in 8-12 weeks to see if your levels are improving. For people managing chronic iron deficiency or taking long-term iron therapy, testing every 3-6 months helps ensure your treatment is working. Athletes and pregnant women may need more frequent monitoring every 2-3 months due to their increased iron demands and changing needs throughout pregnancy or training cycles.

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.

Iron Deficiency Test - Tiredness & Low Energy 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]

Blood Test for Constant Tiredness and Low Energy

Soluble Transferrin Receptor

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.

Blood Test for Constant Tiredness and Low Energy

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