GRAIL vs Guardant Health (2026)
GRAIL and Guardant Health both screen for cancer from a blood draw using methylation classifiers run in their own laboratories. The difference that decides between them is scope against standing, since one test looks for many cancers without FDA approval and the other for one cancer with it. GRAIL's Galleri looks for a cancer signal across more than 50 cancer types in adults at elevated risk and predicts where it started, as a prescription laboratory developed test priced at $949. In PATHFINDER 2, 60.3 percent of positive results led to a cancer diagnosis and 99.2 percent of negative results held at 12 months. The randomized NHS-Galleri trial of 142,250 people did not meet its primary endpoint of fewer late stage cancers. An FDA advisory panel voted 7 to 2 in September 2026 that benefits outweigh risks, and a decision is pending. Guardant Health's Shield, FDA approved in July 2024, screens average risk adults 45 and over for colorectal cancer and is covered by Medicare. It detected 83.1 percent of colorectal cancers in the ECLIPSE study and 13.2 percent of advanced adenomas, so it finds most cancers but few precancerous lesions, and a positive result goes on to colonoscopy. Guardant also sells blood and tissue tests for therapy selection and recurrence. A program adding a blood based colorectal screening option for average risk adults fits Shield. A program offering broader cancer screening to higher risk adults, alongside guideline screening, fits Galleri.
- The goal is to look for many cancer types at once in higher risk adults.
- Results should predict where in the body a detected cancer started.
- The program can fund a test most insurers do not yet cover.
- Security review wants an ISO 27001 certificate it can open.
- The need is colorectal screening for average risk adults 45 and over.
- Medicare coverage and an FDA approved test are requirements.
- The same company should supply therapy selection and recurrence tests.
- Orders should run through Epic or Flatiron OncoEMR today.
This comparison is published by AI Health Index, an independent research platform that compares healthcare AI vendors objectively. GRAIL and Guardant Health are each graded against the same capability taxonomy, from each vendor's own public materials and the regulatory record, under the AI Health Index verification standard. No vendor pays for placement, and no vendor has reviewed this page. How this evidence is graded
Plain facts
| Fact | GRAIL | Guardant Health |
|---|---|---|
| Primary category | Diagnostics & Genomics | Diagnostics & Genomics |
| Founded | 2016 | 2012 |
| Headquarters | Sunnyvale, California | Palo Alto, California |
| Website | grail.com | guardanthealth.com |
Side by Side
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Each vendor in one paragraph
Written to be quoted whole. Each paragraph opens the AI Health Index profile of the vendor: what the product is, who buys it and what it does.
Multi cancer early detection company (NASDAQ: GRAL). The Galleri test uses targeted methylation sequencing of cell-free DNA from a blood draw, with machine learning classifiers that detect a cancer signal and predict its origin, across more than 50 cancer types. It is prescription only, offered as a laboratory developed test from GRAIL's CLIA certified, CAP accredited laboratory in Durham, North Carolina, and intended for use in addition to guideline recommended screening.
Source: AI Health Index, October 2026
Guardant Health is a publicly traded precision oncology company (Nasdaq: GH), founded in 2012 and based in Palo Alto, California, that runs blood and tissue cancer tests in its own laboratories. Shield, approved by the FDA in July 2024, screens average-risk adults 45 and over for colorectal cancer from a blood draw; its result comes from two methylation classifiers, changed in July 2026 to a methylation-only workflow, and it detects most cancers but few precancerous lesions.
Source: AI Health Index, October 2026
Questions buyers ask
Is Galleri or Shield better for cancer screening?
Shield suits a program adding a blood based colorectal screening option for average risk adults 45 and over, with FDA approval and Medicare coverage. Galleri suits a program offering broader screening to higher risk adults, looking for a signal across more than 50 cancer types alongside guideline screening. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified October 17, 2026. No vendor pays for placement.
Is Galleri FDA approved?
Not yet. GRAIL submitted a premarket approval application in January 2026, and in September 2026 an FDA advisory panel voted 7 to 2, with one abstention, that the test's benefits outweigh its risks. Galleri is offered as a prescription laboratory developed test from GRAIL's laboratory in Durham, North Carolina, while Shield has been FDA approved since July 2024. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified October 17, 2026. No vendor pays for placement.
How accurate are Galleri and Shield?
In PATHFINDER 2, 60.3 percent of positive Galleri results led to a cancer diagnosis and 99.2 percent of negative results held at 12 months. Shield detected 83.1 percent of colorectal cancers in the ECLIPSE study but 13.2 percent of advanced adenomas, so it finds most cancers but few precancerous lesions. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified October 17, 2026. No vendor pays for placement.
What did the NHS-Galleri trial find?
The randomized NHS-Galleri trial of 142,250 people in England did not meet its primary endpoint of fewer stage III or IV cancers after three annual rounds. The New England Journal of Medicine carried the result in September 2026. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified October 17, 2026. No vendor pays for placement.
How much do Galleri and Shield cost?
Galleri lists at $949 and is sold through health systems, employers, life insurers, health plans and individual orders. Shield is covered by Medicare. On either test, a positive result leads to further diagnostic work that the test price does not include. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified October 17, 2026. No vendor pays for placement.
Related comparisons
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GRAIL is listed on NASDAQ as GRAL and based in Sunnyvale, California. Guardant Health is listed on Nasdaq as GH and based in Palo Alto. Both tests come with error rates, denominators and results by subgroup, and neither company takes responsibility in contract for a missed cancer or a false alarm. A positive result on either test leads to further diagnostic work that the test price does not include.