Methylene blue goes viral—but what is the R&D backstory on this 150-year-old dye?

Methylene blue is suddenly the talk of social media, thanks to a viral clip showing Robert F. Kennedy Jr., likely the incoming health secretary, adding a striking blue liquid to his in-flight beverage. Overnight, searches for “methylene blue” spiked, with Google Trends data revealing a dramatic jump in February 2025 (see chart below). Newsweek notes the clip was viewed 8.1 million times.

Online vendors selling the substance tout snake oil-like claims, asserting without evidence that it can boost energy and metabolism, enhance cognition, improve mood, and slow aging. Yet this synthetic dye has a rich, research-heavy backstory that goes far beyond TikTok memes and trending hashtags.

Methylene blue’s history in scientific inquiry dates back nearly 150 years. Heinrich Caro, a German chemist, synthesized it in 1876 when employed at the chemical firm BASF. It first found use as a textile dye, and it quickly found its way into medical and microbiological labs when scientists discovered that it could selectively stain bacteria. In 1891, Paul Ehrlich used it to stain malaria parasites, laying the groundwork for modern chemotherapy. By the 1930s, the substance found adoption as first-line treatment for methemoglobinemia (FDA-approved in 1950).

Here’s a recap of common R&D uses for methylene blue:

• Blood smear analysis: A fundamental staining agent in hematology, helping differentiate blood cells and detect parasitic infections.
• Antimicrobial photodynamic therapy (aPDT): Under certain light wavelengths, methylene blue produces reactive oxygen species that kill drug-resistant bacteria and even viruses (Springer Nature). This technology has sparked interest for wound dressings.
• Pain and shock management: Some clinical research explores MB injections to relieve chronic pain—particularly low back pain caused by intervertebral disc degeneration—by reducing inflammatory mediators such as excess nitric oxide. (See: Frontiers in Neuroscience (2021) and Progress in Facial Plastic & Maxillofacial Surgery (PFM) Journal (2022)). MB’s ability to restore abnormal vasodilation and modulate inflammation has also been investigated in conditions like osteoarthritis and colitis.
• Neuroprotection: Some studies suggest that methylene blue may bolster mitochondrial function, spurring investigations into Alzheimer’s, Parkinson’s, and other neurodegenerative conditions.
• Photodynamic cancer imaging and therapy: Ongoing research harnesses MB’s strong optical properties to highlight tumors and lymph nodes in surgical oncology. When activated by specific wavelengths of light, MB can produce reactive oxygen species that selectively kill tumor cells (photodynamic therapy, PDT). (See: PFM Journal (2022)).
• Potential adjuvant for COVID-19 and viral inactivation: In addition to its role in pathogen inactivation in blood products, studies have proposed MB for early-stage COVID-19 treatment. Under light exposure, MB can damage viral RNA and mitigate disease severity. (Reference: Pharmaceuticals (MDPI, 2022) and Annals of Thoracic Medicine (2023)).
• Revival in malaria control: MB is being re-investigated as a fast-acting antimalarial, effective against drug-resistant Plasmodium falciparum. It uniquely kills mature gametocytes (transmissible stages) that other antimalarials often spare. (See: mBio (2022).)
• Advanced photodynamic antimicrobial surfaces: Researchers are blending MB with nanoparticles (e.g., gold or graphene-based) to create “light-activated” antibacterial coatings for surfaces, wound dressings, and implants. Some coatings remain antimicrobial even in the dark, reducing hospital-acquired infections. (See: R&D World (2014) – Background article on dual-dye surface and Polymers (MDPI, 2023)).
• Neuroprotection: In animal models of Alzheimer’s-like pathology (chronic cerebral hypoperfusion in rats), low-dose MB preserved mitochondrial cytochrome oxidase activity and protected memory. Ongoing human trials explore MB or its derivatives (e.g., “hydromethylthionine”) for Alzheimer’s or Parkinson’s. (See: Frontiers in Cellular Neuroscience (2020)).
• Energy storage and “green battery” research: Emerging work uses MB in redox flow batteries (as the catholyte) or as a carbon-doping precursor to improve lithium–sulfur batteries. MB’s redox activity helps store charge efficiently. (See: ACS Energy Letters / PMC (2024) and the Press Release at EurekAlert! (2022)).
• Wastewater treatment and catalytic degradation: MB is widely used as a test molecule to gauge new photocatalysts’ effectiveness in degrading organic contaminants under visible or UV light. Success in degrading MB signals potential for broader industrial wastewater applications. (See: Frontiers in Chemistry (2024)).
• Wound dressings: Incorporating MB into alginate or polymeric hydrogels allows on-demand photodynamic disinfection of chronic wounds. Light activation triggers production of reactive oxygen species that kill bacteria without systemic antibiotics. (See: Polymers (2023)).

Google Trends hits for “methylene blue” jumped from a low baseline (scores around 5–17) to a high of 100 on February 6. If you compare the lowest baseline value (around 5) to the peak of 100, that’s roughly a 1,900% increase. If you compare 17 to 100, it’s closer to 500%, although interest in it started increasing in January. Although interest began ticking upward in January, the real surge came once the clip amassed millions of views in early February.