What's this test for?

This test is ideal if you're currently taking 6-Mercaptopurine (Purinethol) or Azathioprine (Imuran) for conditions like inflammatory bowel disease, rheumatoid arthritis, leukemia, or after a kidney transplant. It helps check whether your body is processing these medications in a safe and effective way. This is especially useful if you've noticed side effects or if your symptoms haven't improved as expected on your current dose.

What happens after I get my results?

Your results will show up in your account with each metabolite level explained alongside its normal range. If your levels fall outside the expected range, the report will outline simple next steps, such as timing considerations around your medication or how soon to retest. You can download a standard lab report from your account at any time, and the trends feature lets you track your metabolite levels over multiple tests to see how your body responds over time. If a result looks dangerously abnormal, seek medical care right away.

Who should consider this test?

Anyone currently on Azathioprine or 6-Mercaptopurine therapy should consider this test, especially if it's been a few weeks since starting or changing a dose. It's also useful if you're experiencing possible side effects like unusual fatigue, easy bruising, or stomach upset, since these can signal your body isn't processing the drug typically. People managing inflammatory bowel disease, rheumatoid arthritis, leukemia, or post-transplant care are common candidates.

What symptoms indicate I may need this test?

Watch for signs like unexplained fatigue, easy bruising or bleeding, frequent infections, stomach pain, or yellowing skin, since these can point to your body building up too much or too little of the active drug. If your inflammatory bowel disease or rheumatoid arthritis symptoms haven't improved despite being on medication, that's another reason to check your levels. Sudden drops in white blood cell counts noticed during routine monitoring can also be a trigger for this test.

When will I get my results?

Results are typically ready within about 7 days of your sample being received at the lab. You'll get a notification once your report is available in your account. This timeframe allows the lab to accurately measure the specific drug metabolite levels in your blood cells.

What is thiopurine metabolite testing and why does it matter?

This test measures two byproducts your body creates when it breaks down thiopurine drugs: 6-thioguanine nucleotides (6-TGNs) and 6-methyl-mercaptopurine (6-MMPNs). Everyone's body processes these drugs a bit differently based on an enzyme called TPMT, so two people on the same dose can end up with very different metabolite levels. Knowing your levels matters because too little of the active metabolite may mean the drug isn't working, while too much can raise the risk of side effects.

What does a high 6-TGN result mean?

A high 6-TGN level generally means more of the active drug is in your system, which can improve symptom control but also raises the chance of side effects like lowered blood cell counts. This might mean your current dose is stronger than your body needs. Reducing dose timing issues, staying hydrated, and watching for signs of fatigue or infection are practical steps while you plan a retest.

What does a low 6-TGN result mean?

A low 6-TGN level often means the drug isn't reaching a strong enough level in your blood cells to be effective, which could explain why symptoms haven't improved. This can happen if your body breaks the drug down too quickly through a different metabolic pathway. Keeping a consistent medication schedule and discussing timing of doses can help before your next test.

What causes high or low thiopurine metabolite levels?

The biggest driver is how active your TPMT enzyme is — some people naturally have low enzyme activity, which pushes more drug toward the 6-TGN pathway, while others have very high activity, which shifts the drug toward the 6-MMPN pathway instead. Missed doses, inconsistent timing, or interactions with other medications can also skew your results. Diet and hydration play a smaller supporting role in how these metabolites are processed.

How often should I retest my thiopurine metabolite levels?

Many people retest every few months once they're on a stable dose, or sooner if their medication dose changes or new symptoms appear. Retesting after any dose adjustment helps confirm your levels have settled into a safe and effective range. Using the trends feature in your account makes it easy to spot patterns across multiple tests 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.

Thiopurine Metabolites Test - Drug Therapy Monitoring

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]