Methylene blue, a synthetic dye developed in the 1870s, has historical applications in textiles and medicine. It is currently approved by the U.S. Food and Drug Administration (FDA) for the treatment of methemoglobinemia, a rare blood disorder. Despite its established medical uses, methylene blue is also being promoted online for various wellness purposes, leading to discussions about its purported benefits, scientific evidence, and potential health risks.
Historical Context and Approved Medical Applications
Initially developed in the 1870s, methylene blue served as a textile dye. Its early medical uses included the treatment of malaria and as an antidote for cyanide poisoning. In the United States, the FDA has approved methylene blue as a prescription medication specifically for methemoglobinemia, a rare condition affecting red blood cells.
Online Wellness Claims and Promotion
Within online health optimization and biohacking communities, methylene blue is promoted for a range of wellness benefits. Proponents suggest it can improve mitochondrial function, which some link to anti-aging effects, enhanced mood, sharper cognition, and alleviation of jet lag. In early 2024, a public figure was observed in a video using an eyedropper to mix a cobalt blue liquid into water. The substance's appearance was noted to resemble methylene blue products sold online, though the individual did not confirm its identity.
Scientific Research and Findings
Laboratory studies and animal trials have investigated the effects of methylene blue. Research indicates its capacity to enhance cellular energy production by facilitating electron movement within mitochondria, particularly when normal metabolic pathways are compromised or under stress. Studies conducted in rodents and worms further suggest that methylene blue may improve brain energy utilization, reduce inflammation, and offer protection against neurological damage.
In human subjects, several smaller trials have explored potential antidepressant and cognitive benefits from pure methylene blue in specific populations. However, Lorne Hofseth, a researcher at the University of South Carolina College of Pharmacy, describes these findings as preliminary. He also noted ongoing research in the United Kingdom on a modified form of methylene blue for Alzheimer's disease, distinguishing it from products available over-the-counter. Nicole Brandt, a professor at the University of Maryland School of Pharmacy, mentioned that cognitive improvement can be subjective and influenced by daily factors such as sleep and diet.
Potential Health Risks and Adverse Effects
Medical experts, including Hofseth and Brandt, advise against using methylene blue as an unapproved supplement due to potential health risks. Identified adverse effects include:
- Serotonin Toxicity: A severe drug reaction that can cause elevated blood pressure, diarrhea, seizures, and potentially be fatal. Individuals taking certain antidepressants, such as Zoloft (sertraline) and Lexapro (escitalopram), are considered particularly susceptible.
- Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency: Methylene blue may pose dangers for individuals with this genetic disorder affecting red blood cells.
- Discoloration: Consumption of methylene blue can result in temporary blue discoloration of the teeth, tongue, and urine.
Regulatory Oversight and Product Concerns
Concerns have been raised regarding the content and quality of methylene blue products sold over-the-counter. In the United States, dietary supplements are not subject to pre-market FDA approval for safety and efficacy, unlike prescription drugs. While manufacturers must adhere to labeling regulations and may undergo inspections, the FDA monitors safety concerns primarily after products enter the market. Federal oversight resources for supplements are finite.
Methylene blue is listed in an FDA database as a generic prescription drug, indicating it requires a prescription. However, many over-the-counter methylene blue products are not found in federal registries for dietary supplement labels and are not explicitly identified as supplements. Dr. Joshua Sharfstein, a professor at Johns Hopkins Bloomberg School of Public Health and former principal deputy commissioner at the FDA, advises caution regarding these products due to varying safety standards. Jeff Ventura of the Council for Responsible Nutrition also noted the absence of many online methylene blue products in federal registries for dietary supplement labels. The FDA has not provided public comment on the sale of non-prescription methylene blue by online retailers.
Expert Recommendations
Medical professionals recommend that individuals considering methylene blue use consult with a clinician beforehand. Such a consultation can help assess potential risks and discuss any underlying health concerns. A primary care provider can also offer guidance on appropriate interventions for issues like brain fog or fatigue. Hofseth stated that the current risks associated with methylene blue as a supplement are considered to outweigh its potential benefits, and resources spent on it may not yield desired outcomes.