Safety of Combining Methylene Blue with L-Glutamine

Hello, and thank you for reaching out with this question!

The simple answer is that L-glutamine is not known to interact directly with methylene blue, so taking them together in the morning is not expected to cause a problem. There also is no established reason they would need to be separated by a certain number of hours.

Interestingly, although methylene blue is commonly sold and used in supplement or “nootropic” products, it is also available as an FDA-approved prescription drug. The FDA-approved form is an intravenous injection used to treat acquired methemoglobinemia, a condition in which the blood cannot effectively deliver oxygen to the body.

Since methylene blue has a long history of medical use, we actually have considerably more information about its potential drug interactions than we do for many conventional dietary supplements. There is no indication from the available information that it interacts with L-glutamine, although this specific combination has not been formally studied.

The Bigger Concern With Methylene Blue

The more important consideration is whether methylene blue could interact with any of your medications. Methylene blue is a potent, reversible monoamine oxidase-A inhibitor, or MAOI. This means it can interact seriously with medications that increase serotonin, potentially causing a dangerous condition known as serotonin syndrome.

The FDA specifically warns about combining methylene blue with serotonergic medications, including many antidepressants and certain other drugs. Examples include SSRIs, SNRIs, other MAOIs, buspirone, mirtazapine, clomipramine, dextromethorphan and certain opioid pain medications.

Methylene blue should also generally be avoided in people with G6PD deficiency because it can cause the breakdown of red blood cells, known as hemolysis. Additional caution is necessary in people with kidney impairment and during pregnancy.

The Bottom Line

You can generally take L-glutamine and methylene blue at the same time in the morning, and separating them would not be expected to provide any meaningful benefit.

However, I would not recommend taking methylene blue until a pharmacist or doctor has reviewed your complete medication and supplement list. Taking methylene blue at a different time of day from an interacting medication does not eliminate the risk.

It is also important to use only a product specifically manufactured and tested for human use, never aquarium, industrial or laboratory-grade methylene blue.

The FDA-approved methylene blue product is an intravenous medication used for acquired methemoglobinemia. Oral use for energy, cognition or general wellness is not FDA approved, and many of the health claims surrounding it have not been established in well-designed clinical studies.

So, while combining it with L-glutamine does not raise a specific concern, please speak with your doctor or pharmacist before using methylene blue regularly.

Thanks!