Axona is a prescription dietary supplement that claims to target the nutritional needs of people with Alzheimer's disease. Alzheimer's is thought to hinder the brain's ability to break down glucose. According to Axona's marketing materials, the supplement provides an energy source that the brain can use instead of glucose.

It's not clear what benefits, if any, Axona provides. A small study, funded by Axona manufacturers, found that memory and cognition improved for people with mild to moderate Alzheimer's disease.

Another study showed that medium-chain triglycerides, which Axona is, might have a small benefit for certain people with Alzheimer's disease. However, more studies are needed to determine Axona's safety and effectiveness.

Axona is marketed as a medical food, which means it's specially formulated and produced to help manage a condition that causes nutritional deficiencies. The Food and Drug Administration (FDA), however, says Alzheimer's disease doesn't create nutritional needs that require a medical food.

Medical foods are given under doctor supervision. The FDA doesn't require the same high level of approval for medical foods as it does for prescription medications. In 2013, the FDA issued a warning to Accera, the company that makes Axona, to stop marketing Axona as a medical food. As a result, the company tested Axona as a drug. However, the drug failed to show benefit in a phase III clinical trial.

Until more is known, the Alzheimer's Association doesn't recommend the use of medical foods, including Axona, for the treatment of Alzheimer's disease.