Written by the NooBlue editorial team. NooBlue makes and sells methylene blue capsules, gummies and drops, so we have a commercial interest in this question. Every study figure below links to its source at the end of the page, and we say plainly where the evidence stops.
Short answer
Methylene blue can be good for you in a narrow set of circumstances and harmful in others. For a healthy adult who takes no serotonergic medicine, has normal G6PD status and is not pregnant, a low oral dose has a plausible way of supporting cellular energy, and in the best-known human trial the side effect participants reported was blue urine. The human evidence is thin: a few single-dose studies at doses far above a supplement serving, one of which found the opposite of what its authors expected. No trial has tested daily supplement doses in healthy people over months.
It is bad for you if you take SSRIs, SNRIs, MAOIs or other serotonergic medicines (the combination can cause serotonin syndrome), if you have G6PD deficiency, if you are pregnant or breastfeeding, or if the product is industrial, lab or aquarium grade.
Our view: treat it as a personal experiment with a clear safety checklist, not a proven health habit. If you pass the checklist, start with the smallest dose you can take, and talk to your doctor first if you take any prescription medicine.
Is methylene blue good for you? The evidence scorecard
“Good for you” is really five separate questions. Methylene blue does well on one, is unproven on two and carries real risk on the last. Here is how the evidence stacks up for each.
| Question | What the evidence shows | Strength |
|---|---|---|
| Is it a real medicine? | Yes. It has been used in medicine for more than a century. Hospitals give it by injection under monitoring and use it as a surgical dye. | Established clinical use |
| Does it support memory in healthy people? | Two small randomized trials found better memory scores after one large dose. A 2023 study found lower brain blood flow instead. | Limited and mixed |
| Does it support cellular energy? | Cell and animal studies show more mitochondrial activity at low doses and less at high doses. | Mostly lab and animal work |
| Does it make you look younger? | Tested on skin cells in a dish and a lab-grown skin model. No human trial has measured appearance. | Unproven |
| Is it safe to take every day? | No long-term trial of supplement doses exists. It interacts dangerously with common antidepressants. | Unknown long term, clear risks for some people |
So the honest answer depends on who is asking. If you take an antidepressant, it is not good for you, full stop. If you are healthy and curious, it is a compound with an interesting mechanism and a small evidence base, and the rest of this guide helps you decide whether that is enough. For the full list of claims and the studies behind each one, see our review of what the research shows on methylene blue benefits.
What methylene blue does in your body
Methylene blue is a synthetic dye first made in 1876. Its biology comes from one chemical habit: it picks up electrons and hands them on, switching between its blue form and a colorless form called leucomethylene blue. It is not used up in the process, so one molecule can do this many times.
Inside mitochondria, that habit lets methylene blue act as a spare electron carrier in the chain that ends at cytochrome c oxidase (complex IV), the step where cells use oxygen to make energy. In a 2014 review in Biochemical Pharmacology, Gonzalez-Lima, Barksdale and Rojas describe how low-dose USP methylene blue raised mitochondrial respiration and improved memory in animal studies. In human fibroblasts grown in a dish, Atamna and colleagues (FASEB Journal, 2008) found that nanomolar amounts raised complex IV activity by 30%.
Two more properties matter for anyone deciding whether to take it.
- The dose curve bends back. Bruchey and Gonzalez-Lima (2008) reviewed methylene blue’s effects and found a hormetic pattern: responses rise with dose, fall back as the dose climbs, then drop below baseline at higher doses. Cytochrome oxidase activity, for example, went up at intermediate doses and down at high ones. “More is not better” is a literal description of the data.
- It blocks an enzyme that clears serotonin. Ramsay, Dunford and Gillman (British Journal of Pharmacology, 2007) showed that methylene blue is a potent, reversible inhibitor of monoamine oxidase A. That is the root of its most serious drug interaction, covered below.
Our explainer on methylene blue for brain and cellular health goes further into the mitochondrial side, and our history of methylene blue covers how a textile dye ended up in hospitals.
Does methylene blue have any real health benefits?
In healthy people, the evidence comes down to three small studies. All three gave a single dose, and the doses were far larger than a supplement serving.
The memory trials
In a randomized, double-blind, placebo-controlled trial published in Radiology in 2016, Rodriguez and colleagues at the University of Texas enrolled 26 healthy adults aged 22 to 62. Thirteen received 280 mg of oral USP methylene blue (about 4 mg per kilogram) and the rest a placebo. Functional MRI one hour later showed more brain activity during attention and short-term memory tasks, and the methylene blue group gave 7% more correct answers during memory retrieval. Every participant who took methylene blue reported blue urine afterward.
An earlier trial in The American Journal of Psychiatry (Telch and colleagues, 2014) gave 42 adults with a marked fear of enclosed spaces either 260 mg of methylene blue (23 people) or a placebo (19 people) straight after an exposure session. Methylene blue improved memory for the setting of the session. Its effect on fear a month later depended on how the session had gone: people whose fear had dropped by the end did better with methylene blue, while people whose fear stayed moderate or high tended to do worse. The authors concluded that methylene blue helps retain what was just learned, which is only useful if what was learned was helpful.
The study that went the other way
In 2023, Singh and colleagues at King’s College London gave healthy volunteers methylene blue into a vein at 0.5 and 1 mg per kilogram and measured brain blood flow and oxygen use (Journal of Cerebral Blood Flow & Metabolism). Both went down, the opposite of their hypothesis. Harvard Health’s summary puts the fall in brain blood flow at about 8%. The authors suggested the hormetic curve as one explanation: doses that are clinically relevant may already sit on the downslope.
What these studies do and do not tell you
The 280 mg dose in the Rodriguez trial is about 56 times the 5 mg in one of our capsules. So these trials tell you that methylene blue acts on the human brain. They do not tell you what a 5 mg capsule does. We know of no controlled trial that has tested daily doses of 5 to 25 mg in healthy adults over months, and none that has measured energy or fatigue at supplement doses.
That leaves the benefits people describe, such as steadier focus and energy without a caffeine jolt, as reports that fit the mechanism rather than trial results. Our guides to how methylene blue relates to energy, methylene blue for brain fog and whether methylene blue works at all go through each claim against the studies.
Does methylene blue make you look younger?
Not on current evidence. The claim traces mainly to one lab study. In 2017, Xiong and colleagues at the University of Maryland (Scientific Reports) applied methylene blue to cultured human skin fibroblasts and to a lab-grown 3D model of human skin. In the cells it mopped up reactive oxygen species, helped fibroblasts divide and slowed the signs of cell aging. In the skin model it improved hydration and dermis thickness, raised elastin gene activity and caused no irritation.
Those are interesting results, with two big limits. The methylene blue was applied straight to cells and tissue, not swallowed, and no trial has measured wrinkles, tone or any other part of appearance in people. The Atamna study that extended fibroblast lifespan in a dish by more than 20 population doublings has the same limit: cells are not people. Harvard Health lists “slow aging” among the claims supporters make, not among the findings.
If appearance is your reason for looking at methylene blue, our evidence review on methylene blue and aging separates the cell data from the marketing, and our guide to methylene blue and your skin covers staining and skin reactions.
What happens if you take methylene blue every day?
For a healthy adult on a low dose, the changes you can expect are mostly cosmetic. The unknowns are about the long run.
- Your urine will probably turn blue or green. StatPearls, the NCBI clinical reference, calls blue-green urine expected and benign. MD Anderson notes that stool can turn green too, and that this is normal until the compound clears.
- Your mouth may pick up color. Undiluted drops stain. NooBlue gummies don’t leave that blue mouth. Capsules bypass the mouth.
- Some people get side effects. StatPearls records headache, nausea, dizziness and confusion, largely from hospital use at far higher doses. If a low dose makes you feel off, stop and talk to your doctor. Our guide to why methylene blue can make you feel weird covers the common reports.
- The drug interaction is there every day you take it. The enzyme blocking described above does not switch off because the dose is small, so the medicine rules apply to daily use too.
- Long-term effects are unknown. Nobody has run a multi-month trial of daily supplement doses in healthy adults.
Most people who take it daily take it in the morning or early afternoon with food and keep the dose steady for a week or two before changing anything. Our articles on whether methylene blue is safe to take daily, the best time of day to take it and methylene blue side effects and precautions go into each point.
When methylene blue is bad for you
Do not take methylene blue if any of these apply to you
- You take a serotonergic medicine. StatPearls names SSRIs, SNRIs, MAOIs, certain opioids and dextromethorphan. Combined with methylene blue, these can cause serotonin syndrome. A systematic review by Ng and Cameron (2010) found 26 patients who became acutely confused after a methylene blue infusion, and 24 of them were taking a serotonin reuptake inhibitor. Harvard Health warns that adding methylene blue to antidepressants such as fluoxetine or duloxetine “can result in a dangerous and sometimes fatal interaction.” Do not stop a prescribed medicine to make room for it. Talk to your doctor.
- You have G6PD deficiency. StatPearls lists it as a contraindication because methylene blue can break down red blood cells in these people. If you do not know your status, ask your doctor about a test before you start.
- You are pregnant or breastfeeding. StatPearls notes that methylene blue may cause fetal harm in pregnancy. Do not take it while pregnant, or while breastfeeding without your doctor’s advice.
- You have reacted to methylene blue or other dyes before. MD Anderson advises people with dye allergies to avoid it.
Three more situations make it a poor choice.
Tyramine-rich food and drink. Because methylene blue inhibits monoamine oxidase, MD Anderson advises avoiding tyramine-rich foods and drinks while taking it, including red wine, draft beer and aged or fermented cheeses and meats, since the combination can raise blood pressure. Baptist Health gives the same warning about cured meats.
High doses. StatPearls reports low blood pressure and wheezing from about 3 mg per kilogram and significant toxicity at cumulative doses of 7 mg per kilogram, which works out to hundreds of milligrams for an adult. A 5 mg supplement serving is a small fraction of that. Given the hormetic curve, taking more is also unlikely to help.
The wrong product. Harvard Health points out that even pharmaceutical-grade methylene blue contains impurities, and that industrial or chemical-grade methylene blue sold as a stain or dye “should not be used in humans or animals.” Aquarium products are not made for people either. Our guide to lab grade vs pharmaceutical grade methylene blue explains how to tell them apart.
Before you combine methylene blue with anything, read our reference on what not to take with methylene blue, along with who should not take methylene blue and our page on methylene blue and G6PD deficiency.
Why doctors don’t recommend methylene blue
Three of the medical pages that rank highest for this question land in the same place.
- Raphael Wald, PsyD, a neuropsychologist at Baptist Health, says: “I would not recommend using methylene blue unless you discuss it first with your healthcare provider.”
- Carlos Roldan, MD, a pain medicine physician at MD Anderson who researches a methylene blue mouth rinse, writes that “not all the health claims you hear about methylene blue are proven.”
- Harvard Health’s April 2025 overview makes the point that a drug working in a highly specific clinical setting does not mean the general population can or should use it.
Their reasons are sound. The human evidence for everyday use is a few single-dose studies. The interaction involves common antidepressants. There is no agreed wellness dose, and product quality varies widely between sellers. A doctor has little to base a recommendation on and a clear reason for caution.
Where we differ is on the conclusion for healthy adults. We think someone who takes no interacting medicine, knows their G6PD status and is not pregnant can reasonably try a low dose from a documented source, ideally with their doctor in the loop. Our article on why doctors don’t prescribe methylene blue sets out the clinical view in full, and whether you need a prescription for methylene blue covers how it is sold.
Hospital methylene blue and supplement methylene blue are not the same use
Much of what you read about methylene blue online describes the hospital drug. There it is a prescription injection, dosed by body weight and given into a vein under monitoring for a rare problem with how blood carries oxygen, and surgeons use it as a dye to make tissue easier to see. Those doses are many times larger than a supplement serving and go straight into the bloodstream, which is where most of the alarming side-effect lists come from.
Low-dose oral use is a different proposition. The molecule is identical, which is exactly why grade and purity matter. The amount is a small fraction of a clinical dose, and the goal is supporting normal cellular energy in an otherwise healthy adult. The hospital record cuts both ways: it shows the compound is well characterized, and it says nothing about taking 5 mg a day for a year.
If you decide to try it: how to take methylene blue
If you have been through the checklist above and want to try methylene blue, these steps keep the experiment small and sensible.
- Check your medicines first. Ask your doctor or pharmacist about anything you take, especially antidepressants, some pain medicines and cough syrups with dextromethorphan.
- Know your G6PD status. If you have never been tested, ask your doctor.
- Start low. One 5 mg capsule, or 10 drops of a 1% solution (5 mg) diluted in water. Healthspan, a clinician-led telehealth service, says a typical protocol begins at around 5 mg and rises gradually to a maximum of about 25 mg a day, adjusted by a clinician.
- Take it with food, early in the day. Morning or early afternoon suits most people.
- Change one thing at a time. Hold a dose for a week or two before you adjust it, and stop if you feel unwell.
- Buy from a seller that shows its paperwork. Look for a named laboratory report and a plain statement of what it does and does not cover.
We make three formats. The molecule is the same in each, and the difference is how you dose it.
- Ultimate Methylene Blue Capsules: 5 mg of USP-grade methylene blue with 10 mg of vitamin C per capsule, 60 capsules for $37.99, about $0.63 a day at one capsule. The label says to take one capsule daily with food. This is the simplest way to start at a fixed low dose.
- Methylene Blue Gummies: 10 mg of methylene blue with 25 mg of vitamin C per gummy, 60 gummies for $49.99. Chew one a day. They don’t leave the blue mouth that drops can.
- Methylene Blue Drops, 1% solution: 0.5 mg per drop, so 10 drops make 5 mg. A 50 mL bottle costs $29.99 and gives about 100 servings at 5 mg. Best for fine adjustment. Dilute them to limit staining, as our guide to taking methylene blue drops explains.
On testing: NooBlue publishes a report from Contract Testing Laboratories of America on its methylene blue ingredient (report 135621, lot 2025022801). It records an HPLC identity result of “Conforms” and individual results for arsenic, cadmium, mercury and lead. It covers the raw ingredient only. It does not give a purity percentage, and it is not a test of every finished batch.
For daily amounts by goal, see our guide to how many mg of methylene blue to take per day. To choose a format, read our capsules vs liquid comparison and our explainer on what USP grade means. If you are comparing brands, our best methylene blue supplements roundup sets NooBlue against other brands on dose, price and testing, or you can browse the NooBlue shop.
Frequently asked questions
Is methylene blue safe to take every day?
For a healthy adult on a low dose, the known daily effects are mostly harmless, such as blue or green urine. It is not safe with SSRIs, SNRIs, MAOIs or other serotonergic medicines, with G6PD deficiency, or in pregnancy. No long-term trial has tested daily supplement doses, so keep the dose small and check with your doctor if you take any medicine.
Is methylene blue good for your brain?
Two small trials found better memory scores after a single dose of 260 to 280 mg, and brain imaging showed more activity during memory tasks. A 2023 study found that methylene blue lowered brain blood flow. No trial has tested supplement doses of a few milligrams a day, so any brain benefit at those doses is unproven.
Can methylene blue be bad for you?
Yes. Combined with serotonergic medicines it can cause serotonin syndrome, which can be fatal. It is also unsafe for people with G6PD deficiency and in pregnancy, and high doses cause toxicity. Industrial, lab or aquarium methylene blue should never be taken by mouth.
How much methylene blue should you take?
Supplement users typically start at about 5 mg a day, which is one of our capsules or 10 drops of a 1% solution. Healthspan, a telehealth service, describes a typical protocol that rises to a maximum of about 25 mg a day under a clinician. Because the dose curve bends back, the smallest dose that works for you is the target.
Is methylene blue natural?
No. Methylene blue is fully synthetic. It was first made in 1876 as a textile dye and does not occur in plants, food or minerals. Being synthetic says nothing about safety one way or the other. What matters is the grade and whether the seller shows a laboratory report from a named lab that states what was tested.
Does methylene blue give you energy like caffeine?
No. Methylene blue is not a stimulant, and it works on the mitochondrial electron chain rather than on adrenaline or adenosine. People describe the effect as steady rather than a jolt, but no controlled trial has measured energy or fatigue at supplement doses.
The bottom line
Methylene blue is good for you only if you fit its safety profile, and even then the benefits at supplement doses are unproven. If you take no serotonergic medicine, have normal G6PD status and are not pregnant, a low dose from a documented source is a reasonable experiment. Keep it small, keep it steady, and involve your doctor.
This article is for educational purposes only and is not medical advice. Talk to a qualified healthcare professional before starting any new supplement, especially if you take medication or have a health condition.
Sources
- Rodriguez P, Zhou W, Barrett DW, et al. Multimodal randomized functional MR imaging of the effects of methylene blue in the human brain. Radiology. 2016;281(2):516-526. PubMed 27351678 · full text (dose, groups)
- Telch MJ, Bruchey AK, Rosenfield D, et al. Effects of post-session administration of methylene blue on fear extinction and contextual memory in adults with claustrophobia. American Journal of Psychiatry. 2014;171(10):1091-1098. PubMed 25018057
- Singh N, MacNicol E, DiPasquale O, et al. The effects of acute methylene blue administration on cerebral blood flow and metabolism in humans and rats. Journal of Cerebral Blood Flow & Metabolism. 2023;43(2 suppl):95-105. PubMed 36803299
- Gonzalez-Lima F, Barksdale BR, Rojas JC. Mitochondrial respiration as a target for neuroprotection and cognitive enhancement. Biochemical Pharmacology. 2014;88(4):584-593. PubMed 24316434
- Atamna H, Nguyen A, Schultz C, et al. Methylene blue delays cellular senescence and enhances key mitochondrial biochemical pathways. FASEB Journal. 2008;22(3):703-712. PubMed 17928358
- Bruchey AK, Gonzalez-Lima F. Behavioral, physiological and biochemical hormetic responses to the autoxidizable dye methylene blue. American Journal of Pharmacology and Toxicology. 2008;3(1):72-79. PubMed 20463863
- Ramsay RR, Dunford C, Gillman PK. Methylene blue and serotonin toxicity: inhibition of monoamine oxidase A (MAO A) confirms a theoretical prediction. British Journal of Pharmacology. 2007;152(6):946-951. PubMed 17721552
- Ng BK, Cameron AJ. The role of methylene blue in serotonin syndrome: a systematic review. Psychosomatics. 2010;51(3):194-200. PubMed 20484716
- Xiong ZM, O’Donovan M, Sun L, et al. Anti-aging potentials of methylene blue for human skin longevity. Scientific Reports. 2017;7(1):2475. PubMed 28559565
- Ostrovsky A, Afzal M. Methylene Blue. StatPearls, last update January 2, 2026. NCBI Bookshelf NBK557593
- Goldman L, reviewed by Shmerling RH. What to know about methylene blue. Harvard Health Publishing, April 24, 2025. health.harvard.edu
- Roldan C. Methylene blue: Should you take it? MD Anderson Cancer Center, March 3, 2026. mdanderson.org
- Wald R. Methylene blue: benefits, risks and expert guidance. Baptist Health, August 7, 2025. baptisthealth.net
- Healthspan. Methylene blue (read September 25, 2026). gethealthspan.com
- NooBlue product pages and ingredient report (read September 25, 2026): capsules · gummies · drops
