Welcome everyone to another edition of the Doctor’s Note where we talk about what’s on our minds when it comes to your health. 

This week we’re going to talk about G6PD deficiency. Most of you probably haven’t heard about this enzyme deficiency, but it’s important because of how it relates to Methylene Blue (an amazing medicine that has been a game changer for Post Covid Long Haulers, and a host of other neurodegenerative diseases). 

Let’s dive in. 


G6PD Deficiency 


G6PD stands for glucose-6-phosphate dehydrogenase, an enzyme that helps red blood cells work properly. If you don’t have enough G6PD, it’s known as G6PD deficiency.

G6PD deficiency is an inherited condition. In fact, it’s the most common human enzyme deficiency in the world. There’s over 400 million people worldwide with this enzyme deficiency (mostly in men, because it’s an X linked recessive trait). Men have an X and a Y chromosome, so if they get an X that has a mutation on it, they’re going to express it. Women have two X’s, so if they just have one of the genes that has the mutation, they will just carry it, but not express it. In the rare situation that the two X chromosomes both have the mutation, they will express the gene. Note: “express” the gene means they will have the disease. 

Most people that have G6PD deficiency are of African, Asian, or Mediterranean descent. I’ve seen very few cases of it in my career. The deficiency can be from mild to severe (FYI: the blood test will predict this). A lot of people will have a mild case and never know it. In fact, most people with G6PD deficiency never know it. So, why is it important that we check the G6PD? 


G6PD Test 


The G6PD test is a one-time test that tells the amount of G6PD in the blood. This is important for several reasons: (1) The G6PD enzyme helps red blood cells work. They’re sort of like the “housekeepers” for the red blood cells. Note: the red blood cells carry oxygen to all of your tissues. (2) It protects the red blood cells against harmful substances. Without enough of this G6PD enzyme, your red blood cells don’t have protection from oxidative stress. Note: oxidative stress is where your body’s antioxidant defense system can’t control the free radicals (think reactive oxygen species). 

Antioxidants are natural substances in foods, vitamins, and minerals that fight free radicals in your body. The body generates free radicals in response to environmental toxins and other factors like smoking and stress. Note: a big producer of free radicals can be certain foods (i.e.,sugar) and/or medications. In G6PD deficiency, the red blood cells get overwhelmed by these free radicals and start to break down. This can cause hemorrhagic anemia. You see this in rare forms in kids. It can be very serious in infants and newborns, the most common symptoms being: abnormal paleness or lack of color of the skin; jaundice or yellowing of the skin and eyes. 

I like to check the G6PD on a lot of my patients. I don’t see a lot of positive G6PD tests in my neck of the woods, but I like to check it anyway. It may be an overkill, but for some it can be very helpful in terms of what medications you are using, and maybe what food you eat. 


Triggers and Symptoms


Triggers are extremely important. They include:

  • Certain medications 
  • Infections
  • Stress
  • Certain foods (most common)

Eating fava beans is a common trigger. Have you ever heard of fava beans? I’ve never eaten them. They’re called broad beans, in the pea/bean family. They kind of look like lima beans, but bigger and a little darker. For most people they are nutritious, but for those with G6PD deficiency they are a nightmare. Other countries use fava beans more than we do. 

Other foods that might be triggers: 

  • Soy
  • Red wine 
  • Blueberries (which are very healthy otherwise)
  • Tonic water
  • Camphor

Medications that can cause this hemolytic anemia (if you have this particular inherited enzyme deficiency) include: 

  • Antimalarials (chloroquine, hydroxychloroquine)
  • Methylene Blue
  • Sulfonamides
  • Aspirin
  • High Dose IV Vitamin C

This is why, whenever I give someone high dose IV Vitamin C, I always check a G6PD test on them beforehand. Note: It’s ironic because low dose IV Vitamin C is actually good for the people with that enzyme deficiency. Non-steroidal anti-inflammatories can affect it also. 

If you had a reaction, your symptoms would be: 

  • Rapid heart rate
  • Shortness of breath
  • Dark urine
  • Fatigue
  • Paleness
  • Red blood cell count
  • Hemolytic anemia
  • Jaundice 

These are some things to look out for. Again, G6PD is rare, but it needs to be looked at, especially if you’re going to use medications that can be very helpful for other things. Also, it’s important to remember that G6PD deficiency is inherited. Children who have it are born with it because it was passed down in the genes. G6PD is a one-time, inexpensive blood test. I run them every day in my office.  




If you have G6PD deficiency, FIRST remove the trigger. Most people recover on their own. In the rare case it does progress to severe hemolytic anemia (the disorder in which red blood cells are destroyed faster than they can be made, you get jaundice and really sick) you may need oxygen. If it really gets bad, you may need a blood transfusion. That’s why I recommend the G6PD test, so if you have the deficiency, you can avoid the triggers. Simple as that. 


Up Next


My next couple of Notes will be updates on Methylene Blue and High Dose IV Vitamin C. IF YOU TAKE METHYLENE BLUE, YOU SHOULD DEFINITELY GET THE G6PD TEST DONE.  To learn more about Methylene Blue, check out my Common Sense MD podcast on our Performance Medicine YouTube channel.  

I know this all sounds complex, but don’t get bogged down in the minutiae. My goal is to turn the complex into common sense, so that you can make educated decisions about your health.

Till next week