What's this test for?

This test is ideal if you're experiencing unexplained blood clots, especially if they happened at a young age or without a clear cause. It's also useful if you have a family history of clotting disorders and want to understand your own risk. Many people order this after a clot event to help figure out if a protein deficiency played a role.

What's included in this test?

This test measures the amount of Protein C protein in your blood, which is one of the body's natural tools for controlling blood clotting. Looking at the antigen level (the actual amount of protein present) helps tell apart different types of Protein C problems, since some involve low amounts of the protein while others involve normal amounts that just don't work properly.

What happens after I get my results?

Your results will show up in your account with the normal range clearly explained next to your value. If your levels come back outside the normal range, next steps usually involve retesting to confirm the result and looking closely at any recent medications, liver health, or vitamin K status that could affect the reading. You can download a standard lab report anytime from your account, and if you test again in the future, the trends feature lets you see how your levels change over time.

How can I naturally support healthy blood clotting balance?

Staying well hydrated and moving regularly helps keep blood flowing smoothly and lowers clotting risk. Eating a balanced diet with steady vitamin K intake (found in leafy greens) supports normal clotting protein production, but big swings in vitamin K intake can throw off related lab results, so consistency matters more than avoidance. Avoiding smoking and managing weight also reduce overall clotting risk.

When will I get my results?

Results are typically ready within about 7 days of your lab visit. Once they're ready, you'll be able to view them directly in your online account. You'll get a notification so you don't need to keep checking manually.

Who should consider this test?

This test is a good fit for people who've had a blood clot with no obvious cause, those with a close family member who has a known clotting disorder, or anyone whose earlier clotting workup suggested a possible Protein C problem. It's also sometimes used to help sort out whether a clotting issue is inherited or caused by something else, like liver disease or certain medications.

What symptoms indicate I may need this test?

Signs to watch for include swelling, pain, or warmth in a leg (which can signal a deep vein clot), sudden shortness of breath or chest pain (which can signal a clot in the lungs), or a history of miscarriages. If you've had one of these events already and doctors couldn't find a clear cause, that's often when this kind of testing gets ordered.

What does low Protein C antigen mean?

A low result means your body may not be producing enough of this clot-regulating protein, which can raise your risk of forming clots. This can be something you're born with, or it can happen temporarily due to liver disease, certain medications like warfarin, vitamin K issues, or recent surgery or illness. Low results are usually followed up with repeat testing since acute illness and some medications can temporarily lower the number.

What causes low Protein C levels?

Common causes include an inherited genetic deficiency, liver disease (since the liver makes this protein), vitamin K deficiency, use of blood-thinning medications like warfarin, and conditions like sepsis, active clotting, or major surgery. Certain chemotherapy drugs can also lower levels temporarily.

How often should I retest?

If your first result is abnormal, retesting after any acute illness, surgery, or medication change has resolved is usually recommended to get an accurate baseline. For ongoing monitoring, especially if you're on blood thinners or being watched for a known clotting disorder, retesting every 6-12 months is common, but the right interval depends on your specific situation and any recent results.

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 Antigen 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]