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Leptin (Blood)

Does this test have other names?

Leptin serum test

What is this test?

This test measures the amount of leptin in your blood.

Leptin is a hormone that helps regulate your body weight by controlling your appetite and energy level. This test is used to figure out how much body fat you have.

Generally, the amount of leptin in your blood is related to the amount of fat tissue in your body. Leptin is released into your blood by your fat stores. Its main job is to tell your brain to stop eating. Researchers believe some people may have leptin in their body, but it doesn't signal to the brain that they are full. Or their brain is resistant to the signal, so they keep eating.

Obesity is a serious condition that can cause a number of life-threatening diseases, including diabetes, heart disease, high blood pressure, stroke, and cancer.

This test can also be used to assess infertility and look at people with delayed puberty.

Why do I need this test?

You may have this test if your healthcare provider needs to find out how much body fat you have.

Your child might need this test if he or she has delayed puberty. The test can help your child's provider look for possible causes of this.

What other tests might I have along with this test?

Your healthcare provider may also order tests to assess your body fat and find out whether you have diabetes, high blood pressure, or cardiovascular disease. These tests may include:

  • A1C, for diabetes

  • Blood pressure

  • Dual-energy absorptiometry scan, to look at muscle, bone, and body fat

  • BMI

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.

The amount of leptin in your body varies from day to day, so more research is needed to understand how to use the lab values from this test.

In general, amounts of leptin are higher in women than in men. Levels go down as you age. 

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.

What might affect my test results?

Pregnancy can affect your results, as can overeating.

How do I get ready for this test?

You don't need to prepare for this test.


Medical Reviewers:

  • Taylor, Wanda L, RN, PhD
  • Ziegler, Olivia Walton, MS, PA-C