**What's Behind the Wellness Claims for the Synthetic Dye Methylene Blue?**

In recent months, a peculiar trend has emerged among wellness enthusiasts seeking to hack their way to health and longevity: the use of synthetic dye methylene blue. This substance has been around since the 1870s, when it was used as a textile dye. It's also been prescribed as an antimalarial treatment and an antidote for cyanide poisoning.

Today, methylene blue is medication approved by the U.S. Food and Drug Administration (FDA) as a treatment for methemoglobinemia, a rare blood disorder. However, online influencers are promoting it for its supposed wellness properties, claiming it improves the function of mitochondria, which convert nutrients into energy.

Some proponents of methylene blue even claim it has benefits such as slowed aging, better mood, sharper cognition, and alleviates jetlag. But do these claims have any scientific backing? Lorne Hofseth, who studies dyes' effect on cancer and inflammation at the University of South Carolina College of Pharmacy, says lab studies and animal trials have found that methylene blue can help cells make energy more efficiently by giving mitochondria an easier way to move electrons when their normal pathways are damaged or stressed.

However, Hofseth warns that these findings remain preliminary, and the research in humans is limited. "You're wasting your money," he says. "The risks outweigh the benefits." Moreover, methylene blue has been linked to adverse side effects such as serotonin toxicity, which can cause elevated blood pressure, diarrhea, seizures, and even death.

Another concern is that people may not know what they're getting when they buy methylene blue over the counter. Unlike drugs, supplements are not approved by the FDA for safety and efficacy before they go on the market. Manufacturers must follow certain rules around labeling, but there's no guarantee of quality or accuracy.

Dr. Joshua Sharfstein, a professor at Johns Hopkins Bloomberg School of Public Health and a former principal deputy commissioner at the FDA, warns that it's buyer beware with methylene blue, and similar products. "The internet is a big place," he told NPR. "There are a lot of products for sale that are not safe."

It's also unclear whether methylene blue meets the regulatory definition of a supplement. It's listed in an FDA database as a generic drug that requires a prescription, and most methylene blue products are not in a federal registry of dietary supplement labels.

If you're still interested in trying methylene blue, be warned: it could turn your teeth, tongue, and urine bright blue. But more importantly, consult with a clinician to ensure you're not at risk for adverse side effects. And if someone's taking methylene blue for a specific health concern, such as brain fog or fatigue, a primary care provider can also help address those issues.

**The Risks of Methylene Blue**

Adverse side effects from methylene blue include serotonin toxicity, which can cause elevated blood pressure, diarrhea, seizures, and even death. People who take certain antidepressants, including Zoloft and Lexapro, are especially at risk.

Methylene blue could also be dangerous for people who have a genetic disorder affecting red blood cells called glucose-6-phosphate dehydrogenase deficiency.

**The Uncertainty of Online Retailers**

The FDA did not respond to a request for comment on how it's possible for online retailers to sell methylene blue without a prescription. However, Dr. Sharfstein notes that "there are a lot of products for sale that are not safe" and that buyers need to be aware of the risks.

**Conclusion**

While some may claim that methylene blue has wellness benefits, the scientific evidence is limited, and the risks outweigh the benefits. If you're considering trying methylene blue, consult with a clinician first, and be warned: it could turn your teeth, tongue, and urine bright blue.