Frequently Asked Questions

The Galleri test screens for multiple cancers and can be taken annually as a simple blood draw. The test can screen for many aggressive cancers before symptoms appear.1

In a clinical study, the Galleri test detected a signal shared by more than 50 types of cancer.2 See the list of cancer types the Galleri test detected.

Learn more — watch the short video What is Galleri? 

The Galleri test does not detect a signal for all cancers and not all cancers can be detected in the blood. False positive and false negative results do occur. The Galleri test should be used in addition to healthcare provider recommended screening tests.

GRAIL is a healthcare company focused on saving lives and improving health by pioneering new technologies for early cancer detection. GRAIL is the company that manufactures the Galleri multi-cancer early detection test. You may receive information or communications from GRAIL or Galleri about your benefit or the Galleri test.

Recuro Health is a nationwide, independent, telemedicine care provider that can prescribe the Galleri test and support virtual physician consultations.

Cancers growing in the body shed DNA into the bloodstream that carries a unique pattern. The Galleri test looks for these unique patterns and detects them as a signal associated with cancer.2 The Galleri test can screen for many aggressive cancers, often before they become symptomatic,1 including those with no recommended screening tests.2,3 If cancer is detected, the Galleri test helps to provide direction to your healthcare provider on the cancer’s origin (i.e., associated tissue type or organ) and guide the next steps in diagnostic testing.1

Watch the short video How Does the Galleri Test Work? to learn more.

The Galleri test does not detect a signal for all cancers, and false positive or false negative results can occur. The Galleri test does not predict future cancer risk. The Galleri test is available by prescription only.

No. The Galleri test is not a hereditary screening test and does not predict your future genetic risk for cancer. Using a blood draw, the Galleri test looks for DNA fragments in the blood that may indicate the presence of cancer.2

In a clinical study, the Galleri test detected a signal shared by more than 50 types of cancer — including some fast-spreading and aggressive cancers responsible for approximately two-thirds of cancer deaths.2 Galleri is a cancer screening test, meaning it looks for cancer before symptoms appear.1 

See the list of cancer types study participants had when a cancer signal was detected.

The Galleri test does not detect a signal for all cancers, and false positive or false negative results can occur. The Galleri test is available by prescription only.

Nearly 99% of people (ages 50-79) who take the Galleri test will receive a No Cancer Signal Detected result.1 In other words, approximately 1% are expected to receive a Cancer Signal Detected result.

Some of the ways we measure test accuracy are with positive predictive value (PPV) and a false positive rate. A PPV is the probability that a person with a Cancer Signal Detected test result has cancer. False positives occur with any type of cancer screening, such as mammography or stool-based colon screening. A low false positive rate — which may help minimize unnecessary diagnostic procedures, exposure to radiation, and patient anxiety — is a key component to a successful broad- based population cancer screening test.4

Learn more about the Galleri test performance here.

The Galleri test does not detect a signal for all cancers, and false positive or false negative results can occur. The Galleri test should be used in addition to healthcare provider recommended screening tests. The Galleri test is available by prescription only.

The Galleri test is commercially available throughout the United States and in select geographic locations through distributors.

The Galleri test is available by prescription only.

Once you receive your sample collection kit, please do not break the quality seal on it. The collection kit should be opened by the trained technician who draws your blood sample. Store the kit at room temperature until your blood draw appointment. The contents are sensitive to extreme temperatures. For example, do not store the collection kit in a car.

To schedule your blood draw visit: Galleri.com/schedule

No, fasting is not required for the Galleri test.

Approximately 1.5 tablespoons (or about 20 mL) of blood in two tubes is typically drawn from a vein in your arm.

The trained technician who draws your blood will pack and ship your sample back to the GRAIL laboratory for processing. Everything needed to complete the blood draw and return the sample is included in the Galleri kit.

If you or your blood draw technician has any questions, please call GRAIL Customer Service at (833) 694‑2553

Watch the Clinical Laboratory Virtual Tour video to learn more about how your sample is processed at the GRAIL lab. 

If you no longer wish to receive your Galleri test result, contact GRAIL Customer Service by completing the online form on the Contact Us web page or by calling (833) 694‑2553.

Partner lab draw: Your sample will arrive at the lab 1-2 business days after your blood draw. The test result will be available about 2-3 weeks after your sample is received at the GRAIL lab.

On-site events: Your test result from the blood draw event will be delivered in 2-3 weeks. Your result will be communicated to you by the ordering provider at the event. Some samples may take more or less time to process, so not all test results will be released on the same day.

It is important to understand that the timing of a test result does not indicate or predict the outcome of the test, nor does it impact the accuracy of the final result.

Your test result can be requested by contacting GRAIL Customer Service by (833) 694‑2553.

A Cancer Signal Detected result means the Galleri test detected DNA methylation patterns often associated with cancer in the blood sample. About 1 out of every 100 tests has a Cancer Signal Detected result.1

 This result will also include a prediction of the tissue type or organ associated with the cancer signal, called a Cancer Signal Origin (CSO). The CSO helps the patient’s doctor determine the next steps for diagnosis.1

A healthcare provider should interpret the result. The test result is not a cancer diagnosis and requires follow-up diagnostic testing, which may include lab work or imaging ordered by the patient’s healthcare provider to confirm cancer. GRAIL also offers patients and providers additional support and resources, if needed, to help guide the next steps.

The Galleri test does not detect a signal for all cancers, and false positive or false negative results can occur. The Galleri test is available by prescription only.

A No Cancer Signal Detected result the Galleri test did not detect DNA methylation patterns associated with cancer in the blood sample. Nearly 99% of people who use the Galleri test will receive a No Cancer Signal Detected result.1

This result does not completely rule out the possibility of cancer, and the patient should continue with other provider recommended cancer screenings. While the Galleri test is a powerful tool, it cannot detect a signal for all cancers, and not all cancers can be detected in the blood. Some cancers shed little or no DNA into the bloodstream, which makes them unlikely to be detected through a blood test (e.g., brain, skin, and early breast and prostate cancers).⁵ False positive and false negative results do occur. The Galleri test identifies DNA in the bloodstream shed by cancer cells and does not predict future genetic risk for cancer.

 The Galleri test can be taken as an annual blood test. Adding the Galleri test to yearly wellness visits can improve the chance of finding a cancer signal early, when more treatment options may be available.⁶ Patients should ask their healthcare provider when it is best to test again.

The Galleri test is available by prescription only.

While today doctors screen individually for 5 specific cancers (i.e., colon, breast, cervical, lung, and prostate), nearly 70% of cancer-related deaths are caused by cancers that have no recommended screening tests.3,⁷* Adding the Galleri test to annual wellness visits can improve the chance of finding a cancer signal early, when more treatment options may be available.⁶

*Assumes screening is available for all colorectal, breast, cervical, and prostate cancer cases and 46% of lung cancer cases (based on the estimated proportion of lung cancers that occur in screen-eligible individuals older than 40 years).

The Galleri test does not detect a signal for all cancers, and false positive or false negative results can occur. The Galleri test should be used in addition to healthcare provider recommended screening tests. The Galleri test is available by prescription only.

A Cancer Signal Detected test result is not a cancer diagnosis and requires follow-up diagnostic testing to confirm cancer. Follow-up diagnostics may include lab work or imaging ordered by your healthcare provider to confirm cancer. GRAIL also offers patients and providers additional support and resources if needed to help guide the next steps.

Your Galleri test result and health information are confidential. Your test result and other health information will only be collected, used, or disclosed in compliance with the Health Insurance Portability and Accountability Act (HIPAA), as detailed in the GRAIL Notice of Privacy Practices (Grail.com/hipaa)

GRAIL may disclose your health information to any of the following:

  • Your healthcare providers (or their designated representatives)
  • Your health insurance company (if the Galleri test, or any follow-up diagnostic care, is paid for, partially or in full, by your health insurance company)
  • As otherwise described in the GRAIL Notice of Privacy Practices

You may also request your Galleri test result by contacting GRAIL Customer Service at (833) 694‑2553 or customerservice@grail.com. However, the testing is complex, but the results are not; we strongly recommend that you obtain the clinical result directly from the healthcare provider who ordered your Galleri test and that you discuss the test result with your healthcare provider.

All results are automatically shared with the provider who ordered the test. If you would like us to fax your result to an additional healthcare provider, contact GRAIL Customer Service and complete the online form on the Contact Us web page or call (833) 694‑2553 to receive instructions on how to complete a results release form.

Every patient who receives a Cancer Signal Detected result from the Galleri test receives a phone call from a trained healthcare provider to explain the result and ensure the patient has a primary care physician (PCP) with whom the result can also be shared. A GRAIL patient advocate can connect the patient’s PCP with expert peer-to-peer consultation services regarding next steps for diagnostic testing. If the patient does not currently have a PCP, the patient advocate will provide local, in-network primary care navigation support. Once a PCP is found, the patient advocate can connect the patient with expert peer-to-peer physician support and conduct ongoing follow-up to confirm that the appropriate next steps are taken toward diagnostic evaluation.

A Cancer Signal Detected test result is not a cancer diagnosis and requires follow-up diagnostic testing, which may include lab work or imaging ordered by your healthcare provider to confirm cancer.

The Galleri test is recommended for use in adults with an elevated risk for cancer, such as those age 50 or older. The test does not detect all cancers and should be used in addition to routine cancer screening tests recommended by a healthcare provider. The Galleri test is intended to detect cancer signals and predict where in the body the cancer signal is located. Use of the test is not recommended in individuals who are pregnant, 21 years old or younger, or undergoing active cancer treatment.

Results should be interpreted by a healthcare provider in the context of medical history, clinical signs, and symptoms. A test result of No Cancer Signal Detected does not rule out cancer. A test result of Cancer Signal Detected requires confirmatory diagnostic evaluation by medically established procedures (e.g., imaging) to confirm cancer.

If cancer is not confirmed with further testing, it could mean that cancer is not present or testing was insufficient to detect cancer, including due to the cancer being located in a different part of the body. False positive (a cancer signal detected when cancer is not present) and false negative (a cancer signal not detected when cancer is present) test results do occur. Rx only.

The GRAIL clinical laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and accredited by the College of American Pathologists. The Galleri test was developed — and its performance characteristics were determined — by GRAIL. The Galleri test has not been cleared or approved by the Food and Drug Administration. The GRAIL clinical laboratory is regulated under CLIA to perform high-complexity testing. The Galleri test is intended for clinical purposes

  1. Schrag D, Beer TM, McDonnell CH, et al. Blood-based tests for multi-cancer early detection (PATHFINDER): a prospective cohort study. Lancet. 2023;402(10409):1251-60. doi: 10.1016/S0140-6736(23)01700-2
  2. Klein EA, Richards D, Cohn A, et al. Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set. Ann Oncol. 2021;32(9):1167-77. doi: 10.1016/j.annonc.2021.05.806
  3. US Preventive Services Task Force. A, B, and C grade recommendations, cancer, screening [cited 2025 Mar 18]. https://www.uspreventiveservicestaskforce.org/uspstf/topic_search_results
  4. Nabavizadeh N, McDonnell C, Kurbegov D, et al. Safety and performance of a multi-cancer early detection (MCED) test in an intended-use population: initial results from the registrational PATHFINDER 2 study [presentation]. European Society for Medical Oncology (ESMO) Congress; 2025 Oct 17-21; Berlin. https://assets.grail.com/wp-content/uploads/2025/10/ESMO-2025_PF2-Initial-Results_Presentation_FINAL-CLEAN-10.16.2025.pdf
  5. Bredno J, Venn O, Chen X, et al. Circulating tumor DNA allele fraction: a candidate biological signal for multicancer early detection tests to assess the clinical significance of cancers. Am J Pathol. 2022;192(10):1368-78. doi: 10.1016/j.ajpath.2022.07.007
  6. Patel AV. Methylated DNA biomarkers and incident cancer in the American Cancer Society (ACS) Cancer Prevention Study-3 (CPS-3) cohort [presentation]. American Society of Clinical Oncology (ASCO) Annual Meeting; 2023 Jun 2-6; Chicago. https://assets.grail.com/wp-content/uploads/2023/06/Patel_ASCO-2023_ACS-CPS-3-Biobank_oral-presentation_FINAL.pdf
  7. Hackshaw A, Clarke CA, Hartman AR. New genomic technologies for multi-cancer early detection: rethinking the scope of cancer screening. Cancer Cell. 2022;40(2):109-13. doi: 10.1016/j.ccell.2022.01.012