What's this test for?

This test is ideal if you're experiencing unexplained blood clots, swelling, or pain in your legs, or if you have a family history of clotting disorders. It's also useful if you've had multiple miscarriages or a personal history of blood clots and want to understand whether a clotting protein deficiency might be the cause. Knowing your Protein S levels can help explain why your blood may be clotting more easily than it should.

What's included in this test?

This test measures both total and free Protein S, which together give a fuller picture of how well your body can control blood clotting. Protein S is a natural anti-clotting protein, and checking both forms helps identify whether a deficiency is affecting your risk of forming dangerous clots.

What happens after I get my results?

Your results will show up in your account with a clear explanation of the normal range for both total and free Protein S levels. If your levels come back outside the normal range, simple next steps like discussing retesting timing or being mindful of clotting risk factors (like prolonged immobility or smoking) can help you manage things going forward. You can download a standard lab report anytime from your account, and if you test again in the future, the trends feature lets you track how your levels change over time.

How can I naturally support healthy blood clotting balance?

Staying active and avoiding long periods of sitting or bed rest can help keep your blood flowing well and lower clotting risk. Drinking enough water, maintaining a healthy weight, and not smoking all support healthy circulation. If you're prone to clotting issues, wearing compression stockings during long flights or car rides can also help.

When will I get my results?

Results are typically ready within about 7 days after your sample is collected. You'll get a notification once your results are posted to your account, where you can view the detailed report and range explanations right away.

Who should consider this test?

This test is a good fit for people who've had an unexplained blood clot, especially at a younger age, or who have close family members with a known clotting disorder. It's also worth considering if you've experienced repeated pregnancy losses, since clotting issues can sometimes play a role. People starting certain hormone therapies who want a baseline clotting risk check may also benefit.

What symptoms indicate I may need this test?

Watch for swelling, warmth, redness, or pain in one leg, which can be signs of a blood clot. Sudden shortness of breath or chest pain can also signal a clot has traveled to the lungs and needs urgent attention. If you've had recurrent miscarriages or unexplained clotting events, that's another reason to consider testing.

What does low Protein S mean?

Low Protein S means your body has less of this natural anti-clotting protein, which can make your blood more likely to form clots than it should. This can happen due to an inherited deficiency, liver problems, pregnancy, certain medications like blood thinners, or vitamin K deficiency. If your level comes back low, it's worth looking at any of these contributing factors and considering lifestyle changes that support healthy circulation.

What causes low Protein S levels?

Common causes include an inherited genetic deficiency passed down in families, liver disease (since Protein S is made in the liver), pregnancy, use of blood-thinning medications like warfarin, and low vitamin K levels. Acute illness or inflammation can also temporarily lower Protein S levels. Retesting when you're not acutely ill or pregnant can give a more accurate picture of your true baseline level.

How often should I retest?

If your results are within the normal range and you have no symptoms, you likely don't need to retest unless new symptoms or risk factors arise. If your levels were low or borderline, retesting in a few months—once any temporary factors like illness or pregnancy have resolved—can help confirm whether it's a lasting deficiency. People with a confirmed inherited deficiency may want periodic monitoring, especially before major life events like surgery or pregnancy.

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.

Protein S Antigen Test - Blood Clot Risk 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]