Methylene blue is popular on TikTok. What’s behind the claims? : NPR

Health enthusiasts looking to pave their way to health and longevity have a new favorite… turns the tongue blue.

Methylene blue has been around since the 1870s, when it was used as a textile dye. Since then, it has been prescribed as an antimalarial and an antidote for cyanide poisoning. Today it is a drug approved by the US Food and Drug Administration to treat methemoglobinemia, a rare blood disorder.

But online influencers are promoting it for its health benefits. It is gaining popularity among biohackers who are looking to optimize their health through lifestyle changes.

Commentators suggested that Robert F. Kennedy Jr. is taking methylene blue after a video of the nation's top health official circulated earlier this year. He can be seen using a dropper to mix a cobalt blue liquid into a cup of water. Kennedy has never confirmed what he takes, although the bright color and applicator resemble the methylene blue products sold in online stores. And Kennedy is famous taking supplementsand has a history of accepting debunked or unproven scientific claims.

Claim:

Methylene blue improves the function of mitochondria – the components of our cells that convert nutrients into energy – and this leads to many benefits, such as slower aging, better mood and clearer thinking. Some even claim that it makes jet lag easier.

Proof:

Laboratory studies and animal tests have shown 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, says Lorne Hofseth, who studies the dyes' effects on cancer and inflammation at the University of South Carolina College of Pharmacy.

He also cites studies in rodents and worms that showed methylene blue improves brain energy use, reduces inflammation and protects against neurological damage.

In terms of human research, there have been several small studies in selected populations that have shown antidepressant or cognitive benefits of pure methylene blue. But Hofseth says these results remain preliminary, so he strongly discourages people from taking it as a supplement because the risks currently outweigh the benefits.

“You're wasting your money,” he says.

This doesn't mean that methylene blue is a complete scientific dead end. Hofseth points to promising work being done in the UK to create a modified form of the dye to treat Alzheimer's disease. But this methylene blue is different from the dye that people buy as an over-the-counter supplement.

So why might online influencers be convinced that methylene blue helps them feel better and think faster?

“Knowledge is subjective,” says Nicole Brandt, a professor at the University of Maryland School of Pharmacy who studies geriatric pharmacotherapy. “We have good days and bad days if we sleep well and eat well.”

Risks:

Hofseth and Brandt not only waste money, but also warn about the side effects of methylene blue. This includes serotonin toxicity, which is a serious drug reaction that can cause high blood pressure, diarrhea, seizures and even death: People who take certain antidepressants, including Zoloft and Lexapro, are at particular risk.

Methylene blue may also be dangerous for people who have genetic disease the effect on red blood cells is called glucose-6-phosphate dehydrogenase deficiency.

Another problem is that people may not know what they are getting when they buy methylene blue without a prescription.

“We don't really have good oversight or any oversight of dietary supplements and what's in them,” Brandt says.

Unlike drugs, supplements are not approved by the FDA for safety and effectiveness before they go on the market. But they must follow certain labeling rules. Manufacturers are also subject to inspection, and the FDA monitors safety issues once products hit the market.

But federal regulators have limited resources and can't catch every bad actor, said Dr. Joshua Sharfstein, a professor at the Johns Hopkins Bloomberg School of Public Health and a former chief deputy commissioner of the FDA. That's why he says buyers beware of methylene blue and similar products.

“The Internet is a big place,” he told NPR. “There are a lot of products on the market that are unsafe.”

It is also unclear whether methylene blue meets the regulatory definition of a supplement. It is listed in the FDA database as a generic drug requiring a prescription.

Most methylene blue products are not included in the federal registry of dietary supplement labels, according to Jeff Ventura, vice president of public affairs for the Council for Responsible Nutrition. Many of the products you see online are not clearly identified as supplements.

The FDA did not respond to a request for comment on how online retailers can sell methylene blue without a prescription.

Result:

Those who do want to try methylene blue should talk to their doctor first to make sure they are not at risk for side effects. And if someone is taking methylene blue for a specific health problem, such as brain fog or fatigue, a primary care provider can also help address those concerns, says Sharfstein.

If you do decide to try this product, be aware that it may turn your teeth, tongue, and urine bright blue.