Is the Methylene Blue TikTok Trend a Red Flag? Here’s What Docs Have to Say

You might have stumbled upon a startling sight while scrolling TikTok lately: people sipping on bright blue drinks that look more like mouthwash than medicine. The liquid? Methylene blue, a synthetic dye that’s been used medically to treat malaria and blood disorders.¹ But now, it's being rebranded by wellness influencers as a brain-boosting elixir.

Videos claim methylene blue contributes to better brain function, memory, and “mitochondrial support." And because of these alleged benefits, methylene blue has become a buzzy addition to some TikTokers' wellness routines. But are the cognitive benefits real, or is this just another viral overpromise?

We asked two medical experts to weigh in on what you need to know before you sip the blue solution—and whether you should really try it in the first place.

What exactly is methylene blue, and what is it used for?

Methylene blue was first created as a textile dye in the 19th century, says Abhishek Patel, MD, medical advisor at Shed, a virtual wellness clinic.² But not long after, it was repurposed as a medical treatment for conditions like malaria—a serious mosquito-borne illness that causes fever, chills, and sweating.

Today, “medical professionals use this compound to treat [a blood disorder called] methemoglobinemia, which prevents blood from transporting oxygen effectively,” says Bronwyn Mahtani, MD, medical advisory board member at Eden. It’s also used off-label to treat other conditions. (FYI, off-label means a medication that healthcare providers recommend to treat something other than what the drug was originally approved for.) The off-label uses for methylene blue include:

• Vasodilatory shock, a medical emergency that causes poor blood flow and an extreme drop in blood pressure³
• Cyanide poisoning, which occurs when cyanide (a toxic compound) enters your body and disrupts breathing⁴
• Skin conditions like psoriasis, which causes itchy and inflamed patches on the skin
• Oral mucositis, a condition that causes inflammation and ulcers in your mouth⁵

Some research also suggests that methylene blue can help detect, diagnose, or even treat certain cancers—including skin and mouth cancer.^6,7

But while methylene blue shows promise for certain medical applications, using unregulated substances to boost your brain health definitely warrants a closer look.

Does the dye improve brain function? 

Short answer: Maybe. 

“There is preliminary evidence that methylene blue may enhance mitochondrial respiration in neurons and reduce oxidative stress, which could theoretically support brain function,” says Dr. Mahtani. In other words, it might help your brain’s energy centers run more efficiently.

However, research on these claims is very limited, and most studies have only looked at the effects of methylene blue in animals like mice and rats. (This is important to note because not all findings from animal studies are replicated or applicable in human trials.)

One review published in the journal Cells found that methylene blue helped protect mice from the kind of cell damage linked to memory problems.⁸ Another study suggested that small doses might help prevent brain aging and memory loss in rats.⁹

And like Dr. Mahtani mentioned, the keyword here is preliminary.

“This is an area of ongoing research,” Dr. Mahtani explains. “We must be cautious not to overstate claims. At this stage, methylene blue should not be seen as a guaranteed cognitive enhancer, but rather as a compound with intriguing but still-emerging data.”

Dr. Patel agrees: “[Methylene blue] could theoretically benefit brain function, especially in high-demand or aging brains. However, these effects depend on dosage, individual biology, and product purity,” he says. “That said, more rigorous, large-scale human trials are needed to fully validate its efficacy for cognitive enhancement.”

So while the TikTok hype implies that methylene blue is a miracle nootropic (aka brain-boosting enhancer), the actual science suggests cautious optimism with a significant need for extensive research.

Safety, side effects, and risks

Despite its flashy reputation online, methylene blue isn’t risk-free, Dr. Mahtani cautions. Possible side effects of incorporating the dye into your wellness routine include:¹⁰

• Blue-stained urine or skin
• Nausea and vomiting
• Chest pain
• Difficulty breathing

It’s also possible to overdose on methylene blue. “At higher doses, or in individuals with certain health conditions or medication regimens [like antidepressants], it can lead to serotonin syndrome, confusion, or changes in blood pressure,” Dr. Mahtani notes. 

Generally, evidence shows that low doses of methylene blue—roughly 2 milligrams (mg) per kilogram (kg) of body weight—are safe. But doses of 7 mg/kg or more have been linked to these dangerous side effects and complications.

It’s also important to consider product purity. “Pure methylene blue is composed of a single active compound: methylthioninium chloride,” Dr. Patel explains. “However, in supplement form, it’s crucial to ensure it's pharmaceutical-grade and free from contaminants, as industrial or textile-grade methylene blue can contain heavy metals or other harmful impurities.” This is extremely important, especially because the U.S. Food and Drug Administration (FDA) does not regulate non-medical treatments, including supplements or substances.

“That’s why any supplementation should be discussed with a licensed provider who can assess safety on a case-by-case basis,” adds Mahtani. Simply put, before trying the newest TikTok health trend, always check in with your primary care team to ensure that it's safe for you.

So, should you actually use it?

Methylene blue might seem like a smart supplement, but it’s far from a go-to brain booster. “I wouldn't recommend methylene blue as a generalized over-the-counter supplement,” says Dr. Mahtani. “Its use should be personalized, medically supervised, and grounded in a clear understanding of the individual’s health history, current medications, and therapeutic goals.”

In other words: Don’t DIY this one. While the compound holds some scientific intrigue, the risks and lack of robust evidence make self-supplementation of methylene blue a gamble.

“From a holistic wellness perspective, methylene blue may be beneficial for certain individuals seeking enhanced brain function or mitochondrial support, but always under guidance from a knowledgeable healthcare provider,” according to Dr. Patel. “Consider it a targeted intervention—perhaps useful during periods of cognitive fatigue, aging-related decline, or recovery from oxidative stress. But it should not replace foundational wellness practices like nutrition, movement, mindfulness, and sleep.”