Articles

Evidence based

Evidence Based

This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of licensed nutritionists and dietitians strive to be objective, unbiased, honest and to present both sides of the argument.

This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

What Is Methylene Blue? Benefits & Use Cases

Written by Dr. Michael Ruscio, DC on July 4, 2025

Written by Dr. Michael Ruscio, DC on July 4, 2025 — Reviewed by Kellie Blake

• What Is Methylene Blue?|
• How It Works|
• Potential Health Benefits|
• Other Uses|
• Is It Safe?|
• What to Know Before Trying|

Methylene blue might not sound like your typical dietary supplement—and it’s not. Originally used as a textile dye in the 19th century, this vibrant blue synthetic compound later became an FDA-approved medication for treating methemoglobinemia, a rare blood condition.

You might also be familiar with methylene blue if you keep fish—it’s commonly used to help prevent or treat parasitic infections in home aquariums 1.

Today, functional and integrative medicine clinics are exploring methylene blue for a range of human wellness uses. Some see promise in its ability to support mitochondrial function, healthier aging, and sharper cognitive function. Methylene blue is also being investigated as potential help for vector-borne infections like Lyme disease, bartonellosis, and babesiosis.

There’s certainly plenty of buzz around this compound but not much solid science yet. Plus, there are some important cautions to be aware of. 

Let’s take a closer look at methylene blue benefits, and where the evidence currently stands.

What Is Methylene Blue?

Fascinating fact: Methylene blue was the first fully synthetic drug ever used in clinical practice 2.

It’s currently an FDA-approved drug used to treat methemoglobinemia, a condition in which oxidation (electron loss) of the iron in hemoglobin—a protein in red blood cells—interferes with its usual ability to transport oxygen 3.

This rare condition can cause symptoms like blue lips, dark urine, and dangerously low oxygen levels. It’s often triggered by exposure to certain drugs (e.g. dapsone, benzocaine), nitrites, or contaminated water.

But methylene blue also has a growing presence in alternative and complementary health settings.

Taking internet claims at face value, you might believe methylene blue to be something of an anti-aging and cognitive enhancement miracle. Those claims are far-fetched—but there are potential methylene blue benefits worth exploring. 

How Methylene Blue Works in the Body

Although the implications are not fully understood yet, methylene blue appears to affect the body through several well-documented mechanisms.

1. It can act as a ‘reducing agent’, which means it donates electrons to other atoms or molecules. In the case of methemoglobinemia, those donated electrons help restore the iron in hemoglobin to its oxygen-carrying form 3. 
2. It inhibits an enzyme (glutathione reductase) in the malaria parasite, which means the infected person’s immune system can target the infection more easily 3.
3. Methylene blue can also inhibit enzymes that relax blood vessels. This helps with vasoconstriction—narrowing of blood vessels to reduce blood flow and raise blood pressure—and can stabilize dangerously low blood pressure in certain medical situations 3.
4. It’s also an MAO inhibitor, meaning it blocks the activity of the monoamine oxidase enzyme. This prevents the breakdown—and can boost the action—of neurotransmitters like serotonin 4.
5. Methylene blue might also function as an antioxidant—potentially reducing oxidative stress and protecting cells and their mitochondria, which make cell energy 5. 

Methylene Blue: Potential Health Benefits

Although we have some understanding of how methylene blue works in the body, these mechanisms don’t necessarily translate into real-world health benefits.

So far, the wider well-being benefits of methylene blue are speculative, with most of the evidence coming from cell or animal studies, not clinical trials in humans.

That said, for those interested in longevity strategies or struggling with chronic illness or infections, methylene blue could be worth a look between you and your doctor.

Next, I’ll describe what scientific evidence is emerging to support the use of methylene blue in three main health areas: aging/cognition, mood/energy, and infectious diseases.

Anti-Aging and Cognitive Effects

Cell and animal studies, along with some inconclusive early-stage human research, suggest that methylene blue may help protect mitochondria and, in turn, offer potential longevity benefits such as 5:

• Slowed aging of cells
• Improved memory and focus
• Cancer prevention
• Reduced risk of neurodegenerative disease including Alzheimer’s disease

Mouse studies have shown that methylene blue can help reduce the aggregation of tau proteins in the brain—one of the early signs of Alzheimer’s disease 6. This raises hopes that it might slow or prevent this type of dementia.

However, a Phase III clinical trial—the definitive test of a new treatment’s efficacy—produced disappointing results. One possible reason is that methylene blue may target a specific form of tau. While it appears to reduce tau fibrils, it may increase tau oligomers—the type of tau that’s more directly involved in brain cell death and Alzheimer’s onset 6.

In practice, I typically start with safer, well-established cognitive support strategies—like an anti-inflammatory diet, regular exercise, sleep hygiene, stress reduction, and possibly huperzine A supplementation—before considering something as niche as methylene blue.

Still, its ability to reduce oxidative stress (cell damage from free radicals) and support mitochondrial function makes methylene blue an interesting candidate for further research in brain health and aging.

Energy and Mood Support

Through its proposed ability to protect mitochondria from oxidative damage, methylene blue may help support the electron transport chain and ATP production—the foundation of cellular energy production.

This potential mechanism could explain why some people report increased vitality and reduced brain fog when using methylene blue.

However, these effects are still largely anecdotal, and more research is needed to confirm any benefits in humans.

Methylene blue’s MAO-inhibiting (serotonin-enhancing) properties may partly explain the mood improvements some users report. However, MAO inhibitors are powerful substances, making it critical to stick to safe dosages and avoid combining methylene blue with certain medications (I’ll go into more detail on this below).

Antimicrobial and Antiparasitic Potential 

The functional medicine community is exploring whether methylene blue might help manage certain vector-borne diseases—in addition to malaria—in humans.

So far, we have laboratory studies that show methylene blue has antimicrobial effects against Borrelia burgdorferi (responsible for Lyme disease) 7 and Bartonella henselae (cause of cat scratch disease) 8. 

The effects are still under investigation in humans. However, I feel cautiously confident, based on the results of using methylene blue in our own clinic with carefully selected cases of chronic vector-borne infections.

Our guidance for use of methylene blue in vector-borne conditions like borrelliosis, bartonellosis, and babesiosis is informed by the respected clinicians Dr. Richard Horowitz, Dr. Tania Dempsey, Dr. Marty Ross, and Dr. Bill Rawls.

In a published case study by Dr. Horowitz’s team, three patients with relapsing Lyme disease and co-infections all benefited from a protocol including methylene blue, two antibiotics, and an anti-tuberculosis drug 9. 

Although this doesn’t separate out the effects of methylene blue, it suggests the need for further research.

Other Medical Uses

Beyond its approved use for methemoglobinemia, methylene blue has a long history in medicine and has been used off-label (non-FDA-approved) in many clinical contexts. These include 3 10:

• Treating severe low blood pressure (vasoplegic syndrome) when standard medication fails during heart surgery
• As a dye (stain) to highlight where certain cancers have spread
• Relieving pain caused by injecting propofol (a sedation drug used, for example, during colonoscopy)
• Enhancing the effectiveness of chloroquine, an antimalarial drug, in treating drug-resistant malaria 
• Countering brain toxicity caused by the chemotherapy drug ifosfamide
• Helping identify parathyroid glands during surgery
• Acting as part of the treatment strategy in cyanide poisoning
• Alongside photodynamic therapy, helping to heal certain skin conditions such as psoriasis and chronic wounds

Bottom line? The benefits of methylene blue for certain specific and serious medical conditions aren’t in question. What’s unclear is whether it’s safe or effective for more general symptoms and wellbeing, especially without a clear medical reason.

Is Methylene Blue Safe?

The short answer is no—methylene blue is a synthetic compound your body would not normally come across and, as such, must be treated with respect.

That said, methylene blue is typically well tolerated at low doses of under 2 mg/kg body weight 3. At doses over 7 mg/kg, the risk of negative side effects increases significantly 3.

As a rough guide, that equates to:

Serotonin Syndrome Warning

The monoamine oxidase inhibitor (MAOI) action of methylene blue means that when combined with other MAOIs or certain antidepressants, it can cause serotonin syndrome—a serious and potentially fatal condition marked by symptoms such as muscle twitching, agitation, sweating, and tremors 3. 

These effects can occur even at doses as low as 5 mg/kg. If you are taking any serotonergic drugs (like MAOIs, SSRIs, SNRIs, or tricyclic antidepressants), don’t take methylene blue.

Other Special Precautions

You should also avoid methylene blue if you 3:

• Have the genetic disorder G6PD deficiency, which makes red blood cells break down faster than they should
• Are pregnant, especially in the second trimester 
• Have a known allergy or previous severe reaction to methylene blue

Make sure to check into these with your doctor if you’re considering methylene blue. If you have kidney failure or significantly reduced blood flow to the kidneys, you may be able to use methylene blue with caution and a doctor’s oversight.

What to Know Before Trying Methylene Blue 

First and foremost, DO NOT purchase methylene blue online or take it without working with a qualified health care professional. A pharmaceutical-grade version is very different from bulk chemicals or aquarium products, which may contain dangerous impurities.

Before starting treatment, your doctor should order a G6PD test—which checks for glucose-6-phosphate dehydrogenase (G6PD) deficiency. As I mentioned, anyone who has G6PD deficiency mustn’t take methylene blue. 

If you don’t fall into one of the above groups that should avoid methylene blue, you should be safe to try it with clinical supervision. Your practitioner will help you decide if oral administration (capsules, liquid, or lozenges) or having intravenous methylene blue is the better option for you.

Some practitioners also combine methylene blue with light therapy in photodynamic therapy protocols.

Clinical Dosing Protocols

You should work with your practitioner to establish the right dose of methylene blue for your own needs. But as a general guide, these are the dosages we would typically use with our clients taking oral methylene blue:

• Vector-borne illnesses
  • Start with around 50 mg per day, then increase up to 100 mg per day. We have seen some people have Herxheimer (die-off) reactions, so it is best to avoid increasing the dosage until the die-off goes away.
  • In some cases, the dose may need to go as high as 300 mg, twice daily (only if side effects stay manageable).
    
• Mitochondrial dysfunction
  • A typical dose range would be lower—about 10–50 mg per day. 

Common side effects that could occur include: 

• Blue or green discoloration of the urine or tongue (harmless)
• Dizziness, headache, or confusion
• Nausea or mild gastrointestinal discomfort

Methylene Blue Benefits: Still Much to Learn

Methylene blue is a fascinating compound with proven value in medicine. It’s FDA-approved for treating methemoglobinemia and has well-documented effects in certain off-label situations such as severe low blood pressure and malaria.

Although its potential for promoting longevity, supporting mitochondrial function, and killing other infectious microbes is exciting, these benefits remain unproven in large-scale human trials. Methylene blue is not a supplement to self-experiment with, and it is certainly not a cure-all. Most touted methylene blue benefits remain speculative, and it can have side effects.

Used responsibly and under the care of an experienced clinician, methylene blue may offer therapeutic value. But as always—be cautious, stay informed, and avoid the hype.

If you’re interested in using methylene blue or working through any aspect of your health, you can reach out to one of our experienced practitioners for a personalized assessment.

The Ruscio Institute has developed a range of high-quality formulations to help our clients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you. The information on DrRuscio.com is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.