The US Food and Drug Administration has issued warnings to companies that claim to offer therapies or cures for autism. In a statement commemorating National Autism Awareness Month, the FDA noted a handful of medications that it has previously approved for use in autism treatment, as well as therapies to help specific symptoms. But health fraud coordinator Gary Coody said that a number of companies have been told to stop making misleading claims or face legal action.

Of the five "treatments" the FDA cites, some have legitimate medical uses — they just haven't been shown to help autism. Hyperbaric oxygen therapy, for instance, uses a pressurized chamber to deliver high levels of oxygen to a patient. It's an accepted treatment for decompression sickness and some injuries, but it's also become linked to a number of questionable cures. In addition to autism, it's been touted as a way to treat conditions as diverse as asthma, Alzheimer's disease, and spinal cord injuries, but the FDA has previously warned that none of these uses have been proven safe or effective. A 2012 study found no clear indication that hyperbaric oxygen therapy improved autism symptoms.

The same is true for "chelation therapies," which draw heavy metals from the body. In some circumstances, like lead poisoning, chelation therapies are applied under medical supervision. But a variety of over-the-counter sprays, pills, and other products promise to treat autism by removing mercury from the blood. Thiomersal, a mercury-based compound once used in vaccines, has been blamed for causing autism by a small but vocal anti-vaccine movement. But doctors and the FDA have warned that this widely discredited theory doesn't justify using chelation treatments, which can be accompanied by nausea, kidney failure, or death. Probiotics products, also on the list, have shown promise in treating autism, but they aren't accepted as a treatment at the moment. Neither are "detoxifying clay baths," which also promise to draw out toxins.

One of the FDA's most notorious targets is a cure-all called Miracle Mineral Solution, whose creator claims to have found "the answer to AIDS, hepatitis A, B, and C, malaria, herpes, TB, most cancer, and many more of mankind's worse diseases." The operative ingredient in MMS is sodium chlorite, which is later mixed with citrus juice to form a bleach. Consumers, the FDA says, have reported "nausea, severe vomiting, and life-threatening low blood pressure" after consuming it, and federal prosecutors have gone after people attempting to sell it as a medicine.