Methylene Blue: A Dye for Energy and Memory Performance
Laura Chrobok 09.10.2026
A blue dye: methylene blue is an unusual medicinal substance. Its defining characteristic is not its striking colour, but its ability to accept and release electrons — and thereby influence fundamental processes in our bodies.
In today’s article, you will learn what methylene blue does in the body and why this substance, which is more than 100 years old, is now being investigated in a wide range of areas. These include its effects on the blood and mitochondria, as well as fascinating human studies on the brain and mental health — and new clinical findings that demonstrate just how versatile this substance really is.
Methylene Blue — From Dye to Medicinal Substance
Methylene blue, also known as methylthioninium chloride, was originally developed as a synthetic dye in the 19th century. However, the substance soon became of medical interest.
One of its most important properties is its so-called redox activity: methylene blue can accept electrons and subsequently release them again. This enables it to participate in biochemical redox reactions that play a crucial role in numerous processes in our bodies. This ability explains much of methylene blue’s distinctive effects. It is relevant both to its established medical use and to its effects on energy production in our cells.
(Rojas et al., 2012)
Methylene Blue for Methemoglobinaemia
The established medical use of methylene blue is the treatment of acquired methemoglobinaemia.
In this condition, the iron in the red blood pigment haemoglobin is oxidised from its divalent Fe²⁺ form to its trivalent Fe³⁺ form. The resulting methaemoglobin can no longer transport oxygen effectively. If its proportion in the blood rises significantly, the body is therefore at risk of oxygen deficiency. Possible symptoms include headaches, weakness, shortness of breath and a bluish discolouration of the skin and mucous membranes.
Methylene blue acts directly on this problem: it accelerates the conversion of the altered haemoglobin back into its normal form. This enables the haemoglobin to transport oxygen effectively again (Iolascon et al., 2021). In the European Union, methylthioninium chloride is authorised for the acute treatment of methemoglobinaemia caused by medicinal products or chemicals (EMA, 2025).
Methylene Blue for Mitochondrial Energy
Methylene blue is particularly fascinating in connection with mitochondria, which are often referred to as the “powerhouses of the cells”.
A large proportion of the ATP that our cells use to power their energy-dependent processes is produced through the mitochondrial respiratory chain. Within this respiratory chain, electrons are transferred step by step from one molecule to the next.
This is where methylene blue’s redox activity comes into play: at low concentrations, methylene blue itself can accept and transfer electrons. Experimental studies show that it can thereby act as an electron carrier within the mitochondrial respiratory chain and influence cellular respiration as well as the activity of cytochrome c oxidase (Rojas et al., 2012).
Another review describes effects not only on mitochondrial function, but also on oxidative stress and neuroinflammatory processes (Tucker et al., 2018).
This makes the substance particularly interesting for the brain. Nerve cells require large amounts of energy and are therefore particularly dependent on functioning mitochondria. However, many findings concerning more extensive neuroprotective effects of methylene blue come from cell and animal models. This makes the question of which effects can actually be demonstrated in humans all the more interesting.
Methylene Blue for Memory Performance
A randomised, double-blind, placebo-controlled study (Rodriguez et al., 2016) investigated the effects of a low dose of methylene blue in 26 healthy adults between the ages of 22 and 62.
Participants received either methylene blue or a placebo. Before and after administration, the researchers used functional magnetic resonance imaging to examine brain activity during tasks involving sustained attention and short-term memory.
After taking methylene blue, increased activity was observed in several brain regions involved in these tasks. Even more striking was the result of the memory test: methylene blue was associated with 7% more correct responses during subsequent memory retrieval (Rodriguez et al., 2016).
Thus, in healthy people, not only was a change in brain activity observed, but also a measurable improvement in the memory performance investigated. However, the study was small and examined only a single dose. It therefore tells us nothing about the effects of regular or long-term use in healthy people.
Another randomised double-blind study (Telch et al., 2014) also showed that methylene blue can influence memory processes. In this study, 42 adults with claustrophobia underwent exposure training. Immediately afterwards, 23 participants received methylene blue and 19 received a placebo.
One month later, a remarkable association emerged: participants who had successfully completed the training with low levels of fear and subsequently received methylene blue showed less fear than comparable participants in the placebo group. Memory of the context of the training was also better with methylene blue.
However, participants who had completed the training with persistently higher levels of fear did not benefit in the same way.
Methylene blue therefore does not simply enhance “positive memories”. Rather, the results suggest that it influences the consolidation — in other words, the stabilisation — of what has previously been learned.
Methylene Blue for Depressive Symptoms
Methylene blue has also been investigated in psychiatric research in a controlled human study. A six-month randomised double-blind study included 37 people with bipolar disorder who continued to experience depressive symptoms despite treatment with lamotrigine (Alda et al., 2017).
Using a crossover design, the researchers compared a low dose of 15 mg of methylene blue with an active dose of 195 mg.
With the higher dose, depressive symptoms improved significantly on various depression scales. Anxiety symptoms also decreased significantly. By contrast, no significant effect was found on the cognitive functions investigated (Alda et al., 2017).
The study therefore provides clinical evidence of an antidepressant and anxiolytic effect as an adjunctive treatment in the patient group investigated.
In Which Cases Caution Is Required with Methylene Blue
Anyone reading about the interesting findings concerning the brain and memory should be aware of one crucial property of methylene blue: methylthioninium chloride inhibits monoamine oxidase and can therefore interact with serotonergic medicines. The combination can trigger severe and, in the worst case, fatal serotonin syndrome. The European product information warns against concomitant use with SSRIs, SNRIs, MAO inhibitors and certain opioids.
Another important contraindication is glucose-6-phosphate dehydrogenase deficiency, or G6PD deficiency. In people with this condition, the medicine is contraindicated because of the risk of haemolytic anaemia.
(EMA, 2025)
The Dose of Methylene Blue Determines Its Effects
An important characteristic of methylene blue is its so-called hormetic dose–response curve: Different doses can produce opposing effects.
This is also crucial when interpreting the research: a dose that has shown an effect on memory or other processes in a particular study cannot simply be transferred to another application.
Methylene Blue Conclusion: Promising, but Not a Substance for Self-Medication
Methylene blue is far more than an intensely blue dye. Its ability to accept and release electrons explains both its established medical use in methemoglobinaemia and the scientific interest in its effects on mitochondria.
The findings from brain research are particularly remarkable: controlled human studies show effects on memory performance and memory consolidation. Under certain conditions, improvements in depressive and anxiety symptoms have also been observed in people with bipolar disorder.
At the same time, methylene blue is a pharmacologically active substance with pronounced dose-dependent effects and relevant interactions. The research findings to date therefore make it an interesting substance with a wide range of properties — but not something for indiscriminate self-medication.
FAQ — Frequently Asked Questions About Methylene Blue
1. Is methylene blue the same as methylthioninium chloride?
Methylthioninium chloride is the pharmaceutical name for methylene blue. Both terms are therefore found in scientific publications (EMA, 2025).
2. Are there different forms of methylene blue?
Yes. Products intended for laboratory, staining or technical purposes are not automatically suitable for use in humans. With a medicinal substance, defined pharmaceutical quality, purity, manufacturing standards and dosage are crucial (EMA, 2025).
3. Why is methylene blue discussed in connection with biohacking?
The interest is primarily related to its effects on mitochondrial processes and human studies on memory and brain function. However, these research findings do not mean that long-term use for general cognitive enhancement has been clinically demonstrated (Arslan/BARMER, 2026).
4. Why does urine turn blue or green after taking methylene blue?
Its striking colour does not remain without visible traces in the body either. Methylene blue and its metabolites are excreted, among other routes, in the urine. The European product information explicitly lists blue-green discolouration of the urine as a possible consequence of its use (EMA, 2025).
5. Does methylene blue only discolour urine?
No. Because of its intense colour, methylthioninium chloride can also turn stools blue-green and temporarily discolour the skin blue, in addition to affecting the colour of urine. Such discolouration is also described in the European product information (EMA, 2025).
Further information — including on many other topics — can be found not only on our blog, but also in our “Medizinskandale” book series and the “Codex Humanus”, the fifth volume of which was recently published. We look forward to welcoming you to our online shop.
Sources:
· Rojas, J. C. et al. (2012): “Neurometabolic mechanisms for memory enhancement and neuroprotection of methylene blue,” Progress in Neurobiology.
· Iolascon, A. et al. (2021): “Recommendations for diagnosis and treatment of methemoglobinemia,” American Journal of Hematology.
· European Medicines Agency (2025): “Methylthioninium chloride Proveblue: EPAR – Product Information,” EMA.
· Tucker, D. et al. (2018): “From Mitochondrial Function to Neuroprotection – An Emerging Role for Methylene Blue,” Molecular Neurobiology.
· Rodriguez, P. et al. (2016): “Multimodal Randomized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain,” Radiology.
· Telch, M. J. et al. (2014): “Effects of Post-Session Administration of Methylene Blue on Fear Extinction and Contextual Memory in Adults With Claustrophobia,” American Journal of Psychiatry.
· Alda, M. et al. (2017): “Methylene blue treatment for residual symptoms of bipolar disorder: randomised crossover study,” The British Journal of Psychiatry.
· Arslan, L. (2026): “Methylenblau:
Welche Wirkung hat es wirklich?,” BARMER.
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