12 de marzo de 2025 | science

Methylene Blue: An Antiviral Agent?

Methylene Blue is an old medicine that scientists are finding has exciting new uses. A study published in 2021 shows that this bright blue substance can kill both the COVID-19 virus (SARS-CoV-2) and the flu virus (H1N1), even without using UV light.

What Did Researchers Discover?

Scientists at the University of Geneva in Switzerland found something surprising about Methylene Blue (often called "MB" for short). They discovered that MB can destroy viruses even in the dark. Before this study, most people thought MB only worked against viruses when activated by light.

"Our findings reveal that methylene blue displays virus-killing activity against influenza virus H1N1 and SARS-CoV-2 at very low concentrations and without needing UV-activation," the researchers wrote in their paper.

How Does Methylene Blue Fight Viruses?

The study shows that MB works in several different ways to stop viruses:

When tested against the flu virus (H1N1), MB completely stopped the virus after just 2 hours, both with and without light.
Against the COVID-19 virus, MB worked in a dose-dependent way - meaning higher doses worked better. At concentrations between 10-50 μg/ml, it completely stopped the virus after 20 hours. Even at the lowest tested amount (0.08 μg/ml), it still reduced the virus by 99.9% (3.05 log reduction).
Most importantly, MB still worked when added to cells that were already infected with the COVID-19 virus. This suggests it could potentially help treat infections, not just prevent them.

What makes MB special is that it doesn't always need to destroy the virus's genetic material (RNA) to be effective. This means it likely attacks other parts of the virus too, like its outer coating (envelope).

Even Better With Antibodies

One of the most exciting findings was that MB worked even better when combined with blood serum from people who had recovered from COVID-19 (containing antibodies against the virus). When used together, they completely stopped the virus from infecting cells.

Is Methylene Blue Safe?

Methylene Blue has been approved by both the FDA (Food and Drug Administration) and EMA (European Medicines Agency) for decades. It's considered very safe at doses below 5 mg/kg.

The main side effect with long-term or high-dose use is a temporary blue coloration of urine, the whites of the eyes, and skin. These effects go away completely when treatment stops.

The only people who shouldn't use MB are those with:

Sensitivity to thiazine dyes
A condition called glucose-6-phosphate dehydrogenase deficiency

Real-World Possibilities

Based on this research, MB might be useful in several ways:

Prevention: It might help protect people at high risk from getting infected.
Treatment: For people already infected, MB might reduce the amount of virus and help limit how sick they get.
Combined therapy: Used alongside antibodies or other treatments, MB might make them work better.

The researchers noted an interesting observation: during the first wave of COVID-19, a group of 2,500 cancer patients receiving MB treatment had no reported cases of flu or COVID-19. While this doesn't prove MB protected them, it suggests this possibility should be studied further.

What's Next?

This research opens new possibilities for using Methylene Blue against respiratory viruses. The fact that it works against both flu and COVID-19 makes it especially valuable, since people can sometimes be infected with both viruses at once.

"Our work supports the interest of testing methylene blue in clinical studies to confirm whether it can prevent or treat both influenza virus H1N1 and SARS-CoV-2 infections," the researchers concluded.

More studies are needed to confirm these findings in people, but Methylene Blue shows promise as a potential tool to fight viral infections. If you want to try the purest form of Methylene Blue on the market, use code TRY10 at checkout for 10% off your first order.

References

Cagno, V., Medaglia, C., Cerny, A., Cerny, T., Zwygart, A.C.A., Cerny, E., & Tapparel, C. (2021). Methylene Blue has a potent antiviral activity against SARS-CoV-2 and H1N1 influenza virus in the absence of UV-activation in vitro. Scientific Reports, 11(1), 14295. https://doi.org/10.1038/s41598-021-92481-9

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MARCH 2025 |

SCIENCE

Methylene Blue: A Multifaceted Compound with Promising

Applications for UV Protection

Methylene Blue (MB) might be familiar to you as a laboratory dye or a medical treatment, but recent research suggests this century-old compound has remarkable properties that could revolutionize skincare and radiation protection. This versatile substance has demonstrated impressive capabilities ranging from UV protection to radioprotective effects, making it a compound of growing interest in both medical and cosmetic fields.

7 MIN READ

Methylene Blue as a Sunscreen Alternative

A 2021 study published in Scientific Reports by researchers at the University of Maryland and Mblue Labs investigated Methylene Blue's potential as a UV radiation protectant. The researchers found that MB not only provides effective UV absorption but also offers significant advantages over conventional sunscreen ingredients like Oxybenzone.

The study revealed several key findings about Methylene Blue:

It has a broad-spectrum absorption range covering UVA, UVB, and UVC wavelengths
It's more effective than Oxybenzone at blocking high-energy, short-wavelength UVB/C rays
It reduces DNA damage caused by UVB radiation in human keratinocytes
It increases cell survival after UVB exposure
It's a potent reactive oxygen species (ROS) scavenger, outperforming other antioxidants like Vitamin A

Perhaps most importantly, the researchers found that MB is environmentally friendly and safe for marine ecosystems. Unlike Oxybenzone, which has been banned in several locations due to its harmful effects on coral reefs, MB had no negative impact on the growth of coral species in laboratory tests.

"Altogether, our study suggests that MB has the potential to be a coral reef-friendly sunscreen active ingredient that can provide broad-spectrum protection against UVA and UVB," the researchers concluded (Xiong et al., 2021).

Methylene Blue's Radioprotective Properties

Beyond its potential as a sunscreen, Methylene Blue has demonstrated remarkable radioprotective effects. A 1975 study published in the Journal of Radiation Research examined MB's ability to protect rats from gamma radiation.

The researchers found that administering Methylene Blue before radiation exposure significantly reduced radiation damage as measured by several biomarkers:

It reduced increases in serum glutamic oxaloacetic transaminase (SGOT) after radiation exposure
It delayed the rise in serum glutamic pyruvic transaminase (SGPT)
It protected against decreases in serum amylase activity
It preserved serum lipase activity
It delayed the decrease in serum lecithinase A
It preserved protein bands in pancreatic juice that would otherwise be lost after radiation exposure

The researchers concluded that "methylene blue has a marked biochemical radioprotective action on the serum enzymes and on the proteins of pancreatic juice of rats when it is given before exposure" (Chung & Nam, 1975).

This radioprotective effect appears to be optimal when MB is administered shortly before radiation exposure at doses of 38-40 mg/kg, suggesting potential applications in radiation therapy or radiation protection scenarios.

Methylene Blue as an Antioxidant Powerhouse

A particularly impressive aspect of Methylene Blue is its antioxidant capabilities. The University of Maryland researchers compared MB with other popular antioxidants used in skincare, including Vitamin A (retinol) and Vitamin C.

Their experiments showed that:

MB enhanced cell proliferation similar to Vitamin C
MB was the most effective at reducing mitochondrial reactive oxygen species (ROS) in all tested cell lines
When combined with Vitamin C, MB showed synergistic benefits, especially in older skin cells
Unlike BP-3 (Oxybenzone) and Vitamin A, which had minimal effects, MB consistently demonstrated antioxidant properties

"MB is no doubt the most effective ROS scavenger in human skin cells," the researchers stated. The combination of MB and Vitamin C produced "the highest skin cell proliferation rate and lowest cellular stress as determined by mitochondrial ROS assay" (Xiong et al., 2021).

Mechanisms of Action

How does Methylene Blue achieve these diverse protective effects? Several mechanisms have been proposed:

DNA repair activation: MB appears to stimulate DNA repair pathways, potentially reversing damage caused by UV radiation.
Antioxidant cycling: MB has a low redox potential of 11 mV, allowing for efficient cycling between oxidized (MB) and reduced (leucomethylene blue) forms. This facilitates electron transport in mitochondria and reduces superoxide production.
Free radical scavenging: Evidence suggests MB protects biological molecules against radiation-induced oxidation of water and decreases oxygen tension in organisms.
Protection of sulfhydryl enzymes: MB may protect sensitive parts of certain sulfhydryl (SH) enzymes against radiation damage.

Future Applications and Research Directions

The remarkable properties of Methylene Blue suggest numerous potential applications:

Next-generation sunscreens: MB-based sunscreens could provide both UV blocking and DNA damage mitigation while being environmentally friendly.
Anti-aging skincare: The combination of MB and Vitamin C could form the basis of highly effective anti-aging formulations.
Medical radiation protection: MB might be useful for protecting patients undergoing radiation therapy or in radiation emergency scenarios.

Before MB can be widely incorporated into consumer products, regulatory hurdles remain. In the US, the FDA regulates sunscreens as over-the-counter medications, and new ingredients must undergo rigorous safety testing. Nevertheless, the mounting evidence of MB's benefits makes it a promising candidate for future applications.

Conclusion

Methylene Blue's remarkable combination of UV protection, antioxidant properties, and radioprotective effects makes it one of the most versatile compounds being studied for skin protection and health. While more research is needed to fully understand its mechanisms and optimize its applications, the current evidence suggests that this century-old compound may play an important role in next-generation skincare and medical treatments. If you're ready to try the purest form of Methylene Blue on the market, use code TRY10 at checkout for 10% off your first order with Meraki Medicinal.

References

Xiong, Z. M., Mao, X., Trappio, M., Arya, C., el Kordi, J., & Cao, K. (2021). Ultraviolet radiation protection potentials of Methylene Blue for human skin and coral reef health. Scientific Reports, 11(1), 10871.
https://doi.org/10.1038/s41598-021-89970-2
Chung, S. O., & Nam, S. Y. (1975). The Radioprotective Effect against Gamma-Irradiation of Methylene Blue in the Rat with Reference to Serum Enzymes and Pancreatic Protein Fractions Examined by Isoelectric Focussing. Journal of Radiation Research, 16(4), 211-223.