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What is PKU?

PKU is short for "phenylketonuria." People with PKU can't process one of the amino acids found in many foods. The amino acid, called phenylalanine or "Phe" for short, builds up in the body.1

Too much Phe is toxic to the brain and can cause many problems. In infants and children, if PKU is not treated, the resulting high Phe can cause severe mental retardation.1 Even if PKU is treated problems like brain changes, lower IQ, and behavior problems may still occur.2

In adults and teens, high Phe can cause lower intelligence (IQ), poor focus, mood swings, being irritable, depression, slow reaction time, and other problems.3,4,5,6

Lower is better*1

To protect the brain, people with PKU need to keep Phe levels low. Low Phe helps you think better. It helps you control moods. It helps you to be your best. Low Phe is good, and lower is better.*1,2

Keeping Phe low

Since Phe is an amino acid, there is a lot of it in high-protein foods like meat and eggs. It is also in many other foods, like bread and pasta. People with PKU have to eat a diet low in Phe. They avoid high Phe foods, and limit how much they eat of foods with less Phe.1,2

A defective enzyme (PAH) in the body fails to break down Phe leading to high levels in the blood and problems in thinking and behavior

Phe-free formula and other supplements help people with PKU get the other amino acids they need to grow and be healthy.1

Some people can also take a medicine to help lower Phe.14

* Lower is better until you get Phe into the normal range of 1-2 mg/dL. Going lower than 1-2 mg/dL can be unhealthy. Talk with your doctor about the right target range for you.1,2