A patient seated in the chair before a blood draw
In person

Alkaline Phosphatase (ALP)

A liver and bone enzyme, measured from one blood draw.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
None
Nothing to do ahead of time. Water is fine.
Results
1 to 2 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

Alkaline phosphatase (ALP) is an enzyme found mainly in the liver and bones. Levels can rise when the liver or bile ducts are under stress, when bone-building cells are more active, and in later pregnancy. ALP is usually read with other liver tests, and no fasting is needed.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

Adults often check ALP to look at liver or bone health, follow up on a past result, or add it to routine blood work, then review it with a healthcare provider.

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Your result shows how much ALP is in your blood, which can help you and a healthcare provider decide whether the liver, the bones, or something else is worth a closer look.

Alkaline phosphatase (ALP)
ALP is an enzyme found mainly in your liver and bones, with smaller amounts in other tissues. A higher level can relate to the liver or bile ducts, or to bone growth or bone conditions. Because it comes from more than one place, it is usually read alongside GGT and other liver results.
Why it’s measured: An enzyme that can reflect stress on the liver, bile ducts, or bones.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. No fasting needed, and nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 1 to 2 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

ALP is reported as enzyme activity in units per liter (U/L) and shown next to the lab’s reference range for comparison.

  • Your number next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

A high or low ALP on its own is not a diagnosis. A healthcare provider reads it with your other results and your history.

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

ALP is made in several tissues, and the liver and bones make most of what is in your blood. In the liver it is linked to the bile ducts. In bone it comes from the cells that build new bone.

A single ALP result can’t show which tissue a rise comes from, so a healthcare provider may look at other results, such as GGT, to sort it out.

Bone activity can raise ALP, for example while a bone is healing. ALP also rises in later pregnancy. Some conditions that involve neither the liver nor the bones can raise it moderately too.

That is why a high result is read in context, with your history and other tests, rather than on its own.

ALP shows whether an enzyme level is high, low, or within the lab’s reference range. It does not show the cause, and it is not a direct measure of how well your liver is working. A healthcare provider may suggest repeating it or adding other tests, depending on your result and history.

No. ALP needs no special preparation, so any time of day works and water is fine. If you add a test that needs fasting to the same visit, such as some metabolic or iron tests, follow the instructions for that test.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.