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Other name(s):

a-amino-b-methyl-n-valeric acid

Unsubstantiated claims

Please note that this section reports on claims that have not yet been substantiated through studies.

Isoleucine may play a role in how hemoglobin is made. This is the oxygen-carrying pigment inside of red blood cells. It may help control blood sugar. It may also boost energy and endurance. It’s also said to help speed healing of injured muscles. Isoleucine may also help muscle development and lean body mass. 

Recommended intake

Amino acids (AAs) are available as individual AAs or in AA combinations. They also come as part of multi-vitamins, proteins, and food supplements. The forms include tablets, fluids, and powders.

Note that by eating enough protein in your diet, you get all of the amino acids you need.

There are no conditions that increase how much isoleucine you need.

Side effects, toxicity, and interactions

Using a single amino acid supplement may lead to negative nitrogen balance. This can decrease how efficient your metabolism is. It can also make your kidneys work harder. In children, taking single amino acid supplements may also cause growth problems.

You should not take high doses of individual amino acids for long periods of time.

The following people shouldn’t use isoleucine supplements:

  • People who are taking leucine and valine

  • Women who are pregnant or breastfeeding

  • People with maple syrup urine disease (MSUD) or cystinuria