Methylene Blue for Depression: What the Research Actually Shows in 2026

If you searched for methylene blue for depression, start with this: it is not an established treatment, and it is not safe to combine with most antidepressants. What does exist is a small body of real research. Three controlled trials tested methylene blue in people under psychiatric care, two of them at doses far above any supplement serving. Lab studies explain how it acts on mood-related brain chemistry, and case reports explain why it can be dangerous alongside common medicines.

This page walks through that research, what it does and does not show, and the safety rules that matter most. NooBlue sells methylene blue capsules, gummies and drops for everyday focus and cellular energy, so we have a commercial interest in the subject. We do not sell methylene blue for mood care, and nothing here is a claim that our products help with depression. Written by the NooBlue editorial team.

Methylene Blue and Depression: Not an Established Treatment

Methylene blue has a real research history in mood disorders, which is more than most supplements can say. It is still a thin one. Every controlled trial used people under a psychiatrist’s care, two of the three used doses of 195 mg a day or more, and two of the three gave methylene blue on top of a prescription mood stabilizer. No trial has compared it head to head with a modern antidepressant.

Two of the three trials found their effect at 195 to 300 mg a day, and in both of those the comparison arm was 15 mg. The third, from 1987, reported a result at 15 mg against placebo, and nobody has repeated it. When we searched PubMed in September 2026 for methylene blue studies of mood published since 2015, the only controlled clinical trial we found was the 2017 one. The rest were lab studies, imaging studies and case reports.

Who Should Not Take Methylene Blue

Read this list before anything else on the page. It applies to supplement servings as well as prescription doses.

• Anyone taking an SSRI, SNRI, MAOI or other serotonergic medicine. Methylene blue is a potent inhibitor of monoamine oxidase A (MAO-A), one of the enzymes that break down serotonin, and it has been reported to trigger serotonin toxicity in patients taking SSRIs (Ramsay et al., 2007). Serotonin syndrome is a medical emergency. The list includes common antidepressants such as sertraline, fluoxetine, escitalopram, venlafaxine and duloxetine, as well as tramadol, dextromethorphan cough medicines and St. John’s wort. Our guide to what not to take with methylene blue has the longer list.
• People with G6PD deficiency. Clinical references list G6PD deficiency as a contraindication because methylene blue can break down red blood cells in people with it (StatPearls, 2026). A blood test can check your status. See methylene blue and G6PD deficiency.
• Anyone pregnant or breastfeeding. Methylene blue given into the amniotic fluid has been linked to serious harm to the fetus (StatPearls, 2026). Do not take it while pregnant or breastfeeding.
• Anyone under 18. NooBlue products are for adults.
• Anyone who takes a prescription medicine. Talk to your doctor or pharmacist first, even if your medicine is not named here.

Methylene blue can also turn urine blue or green, with any format. Clinical references describe this as expected and benign, but it alarms people who were not warned. Drops can stain the mouth and tongue, gummies avoid that, and capsules are swallowed whole.

If you have depression and already take an antidepressant, do not add methylene blue, and do not stop your medicine to make room for it. Both decisions belong with the doctor who prescribes it. Our pages on methylene blue and serotonin syndrome and who should not take methylene blue cover the warning signs and every group that should avoid it. If you are in crisis or thinking about harming yourself, call or text 988 in the US, or contact your local emergency number.

If none of those warnings applies to you and you want methylene blue for everyday focus and cellular energy, which is what NooBlue makes it for, these are the three formats.

A Century of Methylene Blue in Psychiatry

Methylene blue was first made in 1876 by a German chemist, as a dye, and moved into medicine soon after (Liester, Psychology Today, 2024). Psychiatrists have tried it for more than a century, first in psychotic illness and later in mood disorders. That history is set out in a 2019 review by Martin Alda, the Dalhousie University psychiatrist who led the most recent trial (Alda, CNS Drugs, 2019). Our article on the history and uses of methylene blue covers the rest of the story.

The controlled research starts with G. J. Naylor and colleagues, who ran two trials in the mid-1980s. Interest then went quiet for about thirty years, until Alda’s group published a 6-month crossover trial in 2017.

That history matters for one reason. Methylene blue is not a new discovery that doctors have overlooked. It has been tested, the results were encouraging but small, and nobody has yet run the large trial that would settle the question.

The Three Controlled Trials in Detail

Naylor, 1986: two years alongside lithium

This was a two-year maintenance trial in 31 people with bipolar illness (then called manic-depressive psychosis), all kept on lithium. Each person spent one year on 300 mg of methylene blue a day and one year on 15 mg, double-blind, in a crossover design. During the 300 mg year they were significantly less depressed than during the 15 mg year. Manic symptoms did not differ (Naylor et al., Biological Psychiatry, 1986).

The authors listed the weaknesses themselves: a small sample, only 17 people completing both years, simple rating scales, doubts about whether the blinding held, and uncertainty over whether 15 mg really behaved like a placebo. That last point comes up again below.

Naylor, 1987: three weeks at 15 mg

The next study compared 15 mg of methylene blue a day with placebo over three weeks in patients with severe depressive illness. The abstract reports significantly greater improvement on methylene blue, calls it “a potent antidepressant” at that dose, and says further clinical evaluation is essential (Naylor et al., Biological Psychiatry, 1987). The abstract does not say how many patients took part, and we found no attempt to repeat the design in the nearly four decades since.

Alda, 2017: six months alongside lamotrigine

This is the most recent trial and the best documented. Researchers in Canada enrolled 37 people with bipolar disorder who still had symptoms despite taking lamotrigine, a prescription mood stabilizer. Everyone spent one phase on 195 mg of methylene blue a day and one phase on 15 mg, double-blind, across 6 months.

On 195 mg, scores improved on the Montgomery-Åsberg and Hamilton rating scales for low mood (P = 0.02 and 0.05) and on the Hamilton anxiety scale (P = 0.02). Mania scores stayed low and stable. Thinking and memory did not change significantly, and side effects were mild and short-lived (Alda et al., British Journal of Psychiatry, 2017).

Two details are easy to miss. Methylene blue was an add-on here, so the trial says nothing about taking it instead of standard medication. And the 15 mg arm was not an inert pill, which makes the placebo response hard to judge.

The 15 mg Question

Fifteen milligrams a day is the figure that travels furthest online, because it comes from the 1987 abstract and sits close to supplement servings. Look at how the three trials used it, though. In 1987 it was the active dose. In 1986 and 2017 it was the comparison dose, described in the 2017 abstract as a low “placebo” dose. A sugar pill would have been a poor comparison, because methylene blue turns urine blue or green and people would know which phase they were in.

So the evidence on 15 mg points two ways at once. One short study found an effect at 15 mg against placebo. Two longer studies treated 15 mg as close to inactive and found their effect at 195 to 300 mg. That is an unresolved signal, not a dose to copy, and it is not a reason to manage depression from a supplement bottle.

How Methylene Blue Acts on Brain Chemistry

Researchers point to several actions that could explain the trial results. Most of this evidence comes from test tubes and animals, so it describes possible mechanisms rather than proven effects in people.

MAO-A inhibition

Methylene blue is a potent, reversible, tight-binding inhibitor of MAO-A, the enzyme that breaks down serotonin and norepinephrine. It also inhibits MAO-B, but only at much higher concentrations. Working with purified human enzyme, Ramsay and colleagues calculated that at the blood levels reported after intravenous doses, MAO-A would be completely inhibited (Ramsay et al., British Journal of Pharmacology, 2007). Older MAOI antidepressants block the same enzyme, and this action is the reason for the interaction warning above.

Nitric oxide signaling

Methylene blue also inhibits nitric oxide synthase and guanylate cyclase. A 2017 review by Delport, Harvey, Petzer and Petzer notes that the nitric oxide and cGMP pathway is closely tied to the biology of mood, anxiety and psychosis, and that inhibiting it has been associated with an antidepressant response (Delport et al., Metabolic Brain Disease, 2017).

An extra electron carrier in mitochondria

Methylene blue can accept and donate electrons. The same review describes it restoring mitochondrial function, improving energy production in nerve cells and limiting superoxide formation, which is why it keeps appearing in research on brain energy. Our explainer on how methylene blue works goes through the redox cycle step by step.

What the animal work adds

In 2018 the same South African group made five methylene blue analogues that are much weaker MAO-A inhibitors than methylene blue itself (IC50 values of 0.518 to 4.73 µM, against 0.07 µM). All five still showed antidepressant-like effects in the rat forced swim test, similar in size to imipramine and methylene blue (Delport et al., ACS Chemical Neuroscience, 2018). The authors take this as a sign that MAO-A inhibition is only part of the story. A swim test in rats is a screening tool, though. It does not show that anything works in people.

Newer imaging work

A 2024 study from the University of Sussex used methylene blue as a probe rather than a therapy. Fifteen people with bipolar I disorder and fifteen matched controls each had two brain scans, one after an intravenous infusion of 0.5 mg/kg of methylene blue and one after placebo. Oxygen use in frontal and anterior cingulate regions fell more in the patients than in the controls (Russo et al., Journal of Affective Disorders, 2024). The study measured brain metabolism, not mood, and it does not show a benefit.

What the Research Has Not Shown

• No trial has tested supplement servings of 5 to 15 mg a day for mood over months. The only study near that range lasted three weeks.
• No trial has compared methylene blue with a modern antidepressant.
• The two longer trials gave methylene blue on top of lithium or lamotrigine, so neither shows what it does on its own.
• All three trials were small. The two abstracts that give a number report 31 and 37 people.
• No study has measured how much MAO-A a 5 mg oral serving inhibits, so nobody can name a safe threshold alongside serotonergic medicines.
• The animal results, including the forced swim test, have not been confirmed in people.

Why Don’t Doctors Prescribe Methylene Blue for Depression?

• The evidence is small. Three short or small trials, the newest from 2017, are not enough to change routine practice.
• It clashes with the medicines most patients already take. Because methylene blue inhibits MAO-A, it cannot be combined with SSRIs, SNRIs and many other antidepressants without a risk of serotonin toxicity (Ramsay et al., 2007). A doctor would have to stop those first, with a gap before starting.
• The doses that showed an effect are prescription doses. 195 to 300 mg a day was given by psychiatric research teams, not self-selected from a bottle.
• Its hospital role is elsewhere. In hospitals, methylene blue is an injected drug for a few emergency uses, not a mood medicine.
• Nobody owns the molecule. It dates from 1876, which leaves little commercial reason to fund the large trials psychiatry would need.

We cover this in more detail in our article on why doctors rarely prescribe methylene blue.

Is Methylene Blue Good for Mental Clarity?

This is the question behind most supplement use, and the evidence here comes from healthy volunteers, not the mood trials. In a 2016 randomized, double-blind, placebo-controlled trial at the University of Texas, 26 healthy adults aged 22 to 62 took a single 280 mg oral dose (about 4 mg/kg) or placebo. One hour later, brain scans showed stronger responses during attention and short-term memory tasks, and correct answers during memory retrieval rose by 7% (Rodriguez et al., Radiology, 2016). A 2017 follow-up from the same team used the same single 280 mg dose and found stronger resting-state connectivity between regions linked to perception and memory (Rodriguez et al., Brain Imaging and Behavior, 2017).

The limits are familiar by now. The volunteers were healthy, it was one dose measured after one hour, and 280 mg is 56 times one 5 mg NooBlue capsule. There is no imaging data at supplement servings. For more on focus and mental energy, see our guides to methylene blue for brain fog and what the research on methylene blue benefits shows.

Where Supplement Servings Fit

NooBlue sells methylene blue for everyday focus and cellular energy in healthy adults who take none of the medicines listed above. That is a different use from the psychiatric trials, and we do not offer it as a substitute for mood care.

• Capsules: 5 mg of USP-grade methylene blue with 10 mg of vitamin C per capsule, 60 capsules, one a day with food (Ultimate Methylene Blue Capsules).
• Gummies: 10 mg of methylene blue with 25 mg of vitamin C per gummy, 60 gummies, one a day. They avoid the blue mouth and tongue that drops cause (Methylene Blue Gummies).
• Drops: a 1% USP solution in a 50 ml bottle at 0.5 mg per drop, so 10 drops give 5 mg (Methylene Blue Drops). Drops can stain the mouth and tongue.

Start with the lowest serving and keep to the label. Our guide to how many mg of methylene blue per day explains serving sizes by format, and the best time to take methylene blue covers timing. If you plan to take it every day, read whether methylene blue is safe to take daily and our summary of methylene blue side effects first.

Grade matters more with methylene blue than with most supplements, because industrial grades are sold as stains and dyes. Harvard Health Publishing warns that chemical-grade methylene blue should not be used in humans (Goldman, 2025). Pharmaceutical grade is defined by the USP monograph, which requires 97.0% to 103.0% methylene blue on the dried basis (USP). NooBlue publishes a report from Contract Testing Laboratories of America (CTLA) on its methylene blue ingredient, with an HPLC identity result and heavy metal results for one ingredient lot. It covers the raw ingredient, not each finished batch. Our guide to methylene blue purity explains what the grades mean.

Frequently Asked Questions

Can methylene blue replace my antidepressant?

No. None of the trials tested methylene blue as a replacement. Two gave it on top of lithium or lamotrigine, and the third lasted three weeks. Combining it with an SSRI or SNRI also carries a risk of serotonin syndrome. If you take an antidepressant, do not stop it or add methylene blue without speaking to the doctor who prescribes it.

Can I take methylene blue with an SSRI?

No. Methylene blue is a potent MAO-A inhibitor, and it has been reported to trigger serotonin toxicity in people taking SSRIs (Ramsay et al., 2007). Clinical references say to avoid combining it with serotonergic medicines and opioids (StatPearls, 2026). The same applies to SNRIs, MAOIs and other serotonergic drugs. Our methylene blue interactions guide lists them.

Why do I feel so good on methylene blue?

No study has measured how people feel on supplement servings, so nobody can answer this with data. Methylene blue does act on brain chemistry, as an MAO-A inhibitor and as an electron carrier in mitochondria, and a single 280 mg dose changed brain activity in healthy volunteers within an hour. Expectation also shapes how any supplement feels. If you feel agitated, sweaty, shaky or confused, especially after starting another medicine, stop and get medical help, because those can be signs of serotonin toxicity.

How much methylene blue did the mood studies use?

The 1987 study used 15 mg a day for three weeks. The 1986 study used 300 mg a day for a year, and the 2017 study used 195 mg a day, with 15 mg as the comparison dose in both. These were supervised research doses, not a protocol to copy. If you have depression, ask your doctor about dosing rather than following a supplement label. The servings in our dosage guide are for a different, everyday use.

Does methylene blue help with anxiety?

The 2017 trial found lower Hamilton anxiety scores on 195 mg than on 15 mg in people with bipolar disorder who were also taking lamotrigine. No trial has tested it for anxiety in anyone else, and there is no data at supplement servings. If anxiety is affecting your daily life, talk to your doctor.

What is the best medication for severe depression?

That depends on the person, and it is a decision for a doctor who knows your history, not for a supplement company. Methylene blue is not one of the standard options. If you are struggling, a primary care doctor or a mental health professional is the right first call. In a crisis in the US, call or text 988, or contact your local emergency number.

The Bottom Line

Methylene blue has more mood research behind it than most supplements: three small controlled trials and a well-described pharmacology. The clearest results came at 195 to 300 mg a day, as an add-on to lithium or lamotrigine, in people under psychiatric care. That does not make it a supplement for depression, and its MAO-A activity makes it unsafe with SSRIs, SNRIs and other serotonergic medicines.

If you are healthy, take none of those medicines, and want methylene blue for everyday focus, start with the lowest serving and read the safety list first. If you have depression, talk to your doctor before trying any supplement. You can see all three formats in the NooBlue shop.

Sources

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