What's this test for?

This test is ideal if you're experiencing unexplained blood clots, a family history of clotting disorders, or if you've had a stroke or clot at a young age. It also helps if you're on blood thinners like warfarin and need to understand how your medication is affecting your clotting proteins. Protein C and S deficiencies can raise your risk of dangerous blood clots, so this test helps identify whether that's a factor for you.

What's included in this test?

This test measures how well your protein C and protein S are working (activity), and if results are abnormal, it automatically reflexes to check the actual amount of these proteins in your blood (antigen levels). Together, these measurements help pinpoint whether a deficiency is due to your body not making enough of the protein or making a version that doesn't work properly. This distinction matters because it helps determine whether a clotting risk is inherited or caused by something else, like medication or liver issues.

What happens after I get my results?

Your results will show up in your account with each value's normal range clearly explained, so you can see exactly where you fall. If your protein C or S levels are low, next steps often include discussing timing with any blood thinners you take and considering retesting since results can shift with certain medications, pregnancy, or illness. You can download a standard lab report from your account at any time, and the trends feature lets you track your levels over multiple tests to see if they're changing.

How can I naturally support healthy blood clotting balance?

Staying active with regular movement helps keep blood flowing well and lowers clot risk, especially if you sit for long periods during travel or work. Eating a balanced diet with foods rich in vitamin K, like leafy greens, supports normal clotting protein function, though you should keep your intake consistent if you're on certain blood thinners. Staying well hydrated and maintaining a healthy weight also reduce strain on your circulatory system. If you smoke, quitting is one of the most effective ways to lower clotting risk naturally.

When will I get my results?

Results for this test are typically available within about 7 days of your blood draw. This timeframe accounts for the specialized nature of clotting factor testing, which sometimes includes additional reflex testing if your initial results come back outside the normal range. You'll be notified as soon as your results are ready to view in your account.

Who should consider this test?

People who've had an unexplained blood clot (like deep vein thrombosis or pulmonary embolism), especially at a young age, should consider this test. It's also worth doing if you have a close family member with a known clotting disorder, if you're pregnant and have clotting risk factors, or if you're being monitored while on blood thinners like warfarin. Anyone with a personal or family history of recurrent miscarriages may also benefit, since clotting issues can sometimes play a role.

What symptoms indicate I may need this test?

Watch for symptoms like swelling, pain, warmth, or redness in a leg (which can signal a clot), sudden shortness of breath or chest pain (which could mean a clot traveled to your lungs), or skin that turns dark or develops sores in patches. Recurrent miscarriages can also be a sign of an underlying clotting issue. If you experience any of these symptoms, especially chest pain or trouble breathing, seek medical care right away rather than waiting for test results.

What does low Protein C or Protein S mean?

Low levels mean your blood may have a harder time regulating clot formation, which raises your risk of developing clots that could block blood flow. This can be something you're born with (congenital) or something that develops from things like liver disease, vitamin K issues, pregnancy, or certain medications. Depending on your situation, this might mean adjusting lifestyle habits, monitoring more closely, or taking specific precautions during high-risk situations like surgery or long flights.

What causes low Protein C or Protein S levels?

Common causes include inherited genetic differences passed down in families, liver disease (since these proteins are made in the liver), vitamin K deficiency, and certain blood thinner medications like warfarin. Pregnancy naturally lowers protein S levels, so this is expected and usually not a concern on its own. Other causes include acute illness, surgery, trauma, or conditions that use up clotting factors faster than the body can replace them.

How often should I retest?

If you're being monitored for a known deficiency or you're on blood thinners that can affect your levels, retesting every few months or as advised may be helpful to track changes. If you had one abnormal result, retesting after a few weeks (once you're not on interfering medications or acutely ill) can help confirm whether it's a persistent issue or a temporary fluctuation. Use the trends feature in your account to keep an eye on your levels over time.

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 C & S Test - Blood Clotting 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]

Protein C and S Activity Blood Clotting Test

Protein C and S Activity with Reflex to Protein C and/or S Antigen

Prescription & all lab fees included

Doctor's guidance included

Fast & convenient

Prescription & all lab fees included

Doctor's guidance included

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.

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Protein C and S Activity Blood Clotting Test

Prescription & all lab fees included

Doctor's guidance included

Fast & convenient

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