G6PD Enzyme Deficiency: Foods, Medicines and Products to Avoid

Why some foods and medicines are a problem

G6PD is an enzyme that protects red blood cells from oxidative damage. When it is low, red cells cope with everyday life but break apart (hemolysis) when they meet a strong oxidant. Fava beans, certain medicines, naphthalene and the inflammation of an infection all create that kind of stress. The result is sudden hemolytic anemia: tiredness, pale skin, yellow eyes and dark urine, usually 24 to 72 hours after exposure.

How strongly you react depends on your variant. The African A- variant usually causes milder, self-limiting episodes. The Mediterranean variant causes more severe ones and is the type most linked with favism. For how the condition is inherited, tested and treated, see our full guide to glucose-6-phosphate dehydrogenase deficiency.

Foods to avoid with G6PD deficiency

Fava beans

Fava beans (broad beans) are the one food with clear evidence. A reaction to them is called favism. It can follow eating fresh, dried, cooked or frozen beans, and rare reports describe reactions to the pollen of flowering fava plants. Breastfed babies have reacted after the mother ate fava beans. Because severity varies widely and is hard to predict, guidance is to avoid them entirely. Check ingredient lists for fava or broad bean flour, falafel made with fava beans, and some Middle Eastern and Mediterranean dishes.

Foods with weak or no evidence

Many online lists also ban soy, other legumes, bitter melon, blueberries, red wine, menthol or sulfites. For most people with G6PD deficiency there is little evidence that these cause hemolysis. Ordinary beans, peas, lentils and chickpeas are not the same as fava beans. If you have a severe variant or have reacted to a food before, ask your doctor for advice specific to you rather than following a long, unnecessary list.

Supplements and herbal remedies

• High-dose vitamin C, especially given into a vein, has caused severe hemolysis. Vitamin C from food is fine.
• Some Chinese herbal medicines, such as Coptis chinensis (huang lian), have been linked to hemolysis and newborn jaundice.
• Large amounts of tonic water (quinine) are sometimes advised against.

Medicines to avoid with G6PD deficiency

Always tell every doctor, dentist and pharmacist that you have G6PD deficiency. The table sorts common medicines by risk, based on major clinical guidelines.

Malaria tablets and travel

G6PD deficiency is common in regions where malaria is found, and two key malaria drugs, primaquine and tafenoquine, can cause dangerous hemolysis. The WHO advises G6PD testing before these are prescribed. If you are traveling, tell the travel clinic about your diagnosis so they choose a safe alternative.

In hospital

Tell the team on arrival. Methylene blue, used to treat methemoglobinemia and in some surgery, can make things worse in G6PD deficiency. Rasburicase, used to prevent kidney damage during cancer treatment, is contraindicated, and many hospitals test G6PD before giving it.

Household products and other triggers

• Naphthalene mothballs and some toilet deodorizer blocks. Babies have had severe hemolysis from clothes or blankets stored with mothballs. Use cedar or other naphthalene-free products, and never let children handle mothballs.
• Henna (natural or black henna tattoos) on the skin of babies and young children has caused severe hemolysis.
• Infections are the most common trigger of all. Pneumonia, hepatitis A, B or E, urinary tract infections and gastroenteritis can all set off an episode. Keep vaccines up to date and see a doctor early for fever.
• Diabetic ketoacidosis can also trigger hemolysis.

What to do if you are exposed

1. Stop the trigger: stop the medicine (after speaking to the prescriber if it is essential), and avoid further contact with the food or chemical.
2. Watch for symptoms for 3 days: dark urine, yellow eyes or skin (jaundice), unusual tiredness, breathlessness or back pain.
3. Drink plenty of fluids to protect the kidneys.
4. Get medical care the same day if any symptom appears. A blood count and bilirubin test show whether hemolysis is happening. Severe anemia may need a blood transfusion.

Most episodes settle within 1 to 2 weeks as the bone marrow replaces the damaged cells.

Babies and children

G6PD deficiency is an important cause of newborn jaundice, which can rise quickly and, if untreated, damage the brain. Parents of a baby with G6PD deficiency should keep the baby away from mothballs and henna, mention the diagnosis at every visit, and check with a pharmacist before giving any medicine or herbal remedy.

Frequently asked questions

What foods should I avoid with G6PD deficiency?

Avoid fava (broad) beans in all forms, including flour and dishes made from them. This is the only food with strong evidence. High-dose vitamin C supplements and some Chinese herbal remedies should also be avoided. Ordinary beans, peas, lentils and soy are safe for most people.

What medicines should I avoid with G6PD deficiency?

The highest-risk medicines are primaquine, tafenoquine, dapsone, rasburicase, pegloticase, methylene blue and nitrofurantoin. Some sulfa antibiotics, high-dose aspirin and phenazopyridine also carry risk. Tell every prescriber and pharmacist about your diagnosis and check new medicines, including herbal products, before taking them.

Is acetaminophen (paracetamol) safe with G6PD deficiency?

Yes, at normal doses acetaminophen is considered safe for people with G6PD deficiency. Follow the label dose. Ibuprofen and low-dose aspirin are also generally safe. An overdose of acetaminophen is dangerous for anyone and can cause hemolysis as well as liver damage.

Can people with G6PD deficiency eat chickpeas, soy or peanuts?

For most people, yes. Chickpeas, soy, peanuts and other legumes have not been shown to cause hemolysis the way fava beans do. If you have a severe variant or have reacted to a food before, ask your doctor for personal advice.

Why are mothballs dangerous with G6PD deficiency?

Many mothballs contain naphthalene, a chemical that damages red blood cells in people with G6PD deficiency. Breathing the fumes, chewing a mothball, or wearing clothes stored with mothballs can trigger severe hemolysis, especially in babies. Use naphthalene-free alternatives.