G6PD (Glucose-6-Phosphate Dehydrogenase): what your level actually means
Also known as: G6PD Enzyme Level, Glucose-6-Phosphate Dehydrogenase · Updated 19 Aug 2026 · Educational — not medical advice
The short answer: Normal G6PD enzyme activity is generally above about 6.4 U/g Hb, and this enzyme protects red blood cells from a specific type of oxidative stress. People with low activity, sometimes below 4 U/g Hb, have G6PD deficiency, an inherited condition that leaves red blood cells vulnerable to sudden breakdown after exposure to certain triggers like fava beans or specific medicines, including some antibiotics and antimalarials.
Where does your value sit?
This G6PD (Glucose-6-Phosphate Dehydrogenase) value is inside the normal range. Your lab's printed reference range takes precedence — ranges vary slightly between laboratories.
What G6PD tells you
G6PD is an enzyme inside red blood cells that helps protect them from oxidative damage. People who inherit reduced G6PD activity are generally healthy day to day, but their red cells can break down rapidly — a reaction called hemolysis — after exposure to certain foods, most notably fava beans, or specific medicines such as some antibiotics, antimalarials, and other oxidant drugs. (Illustration is schematic.)
Common reasons it rises
- Not typically a clinical concern — G6PD activity above the normal range is not associated with a recognized disease pattern.
- Recent hemolytic episode — right after a crisis, surviving young red cells carry more enzyme, so activity can read falsely normal or high; retesting after ~3 months gives the true picture
And reasons it runs low
- Inherited G6PD deficiency — an X-linked genetic condition, more common in males, that reduces enzyme activity from birth.
What should I eat?
Eat freely
- Vegetables, fruit, and whole grains — a normal balanced diet is safe for this condition
- Dal, rajma, and other pulses — safe everyday protein sources for this condition
- Eggs, fish, or chicken — safe protein options if fava beans are avoided
- Leafy greens and citrus fruit — folate and vitamin C support making new red cells
Go easy on
- Unfamiliar foods when travelling or eating out — check whether a dish contains broad or fava beans
- Herbal or unlabelled traditional remedies — unknown ingredients can trigger red cell breakdown
Best avoided
- Fava beans (broad beans) — the best-known trigger for a hemolytic reaction
- Any new medicine without checking G6PD status — several common drugs can trigger a hemolytic crisis
- Sulfa medicines, nitrofurantoin, and quinolones — these antibiotics are known triggers in this condition
- Antimalarials such as quinine or primaquine — these are classic triggers unless a doctor prescribes them
- Naphthalene mothballs — breathing mothball fumes can trigger red cell breakdown
Can I exercise?
Stop and get help if
- Dark or tea-coloured urine
- Yellowing of the skin or eyes
- Chest pain, fainting, or severe breathlessness
- Pale skin with a rapid heartbeat
Regular activity is safe between episodes; the main focus is avoiding known food and medicine triggers.
Your week
- 4-5 days: 20-30 minute walk or light cardio
- 2 days: light strength training
- Rest fully during and after a hemolytic episode
- Resume gradually once your doctor confirms recovery
Start here: A 15-minute walk most days once you feel well.
Skip for now
- Intense exercise during or right after a hemolytic episode
- Ignoring dark urine or unusual tiredness after exertion
Check with your doctor first: If you or a family member has G6PD deficiency, tell every doctor and pharmacist before any new medicine is started, and keep naphthalene mothballs and henna away from babies.
General guidance for adults — not a personal diet plan. Your doctor or dietitian knows your full picture.
Checked against: G6PD deficiency (MedlinePlus) · G6PD test (MedlinePlus) · Glucose-6-phosphate dehydrogenase deficiency (MedlinePlus)
What to do next
Ask your doctor: “Which specific foods and medicines should I avoid given this result?”
Ask your doctor: “Should my family members be tested given the inherited nature of this condition?”
Ask your doctor: “If I recently had a hemolytic episode, does this result need to be repeated later for accuracy?”
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Questions people ask
What should I avoid if I have G6PD deficiency?
The best-known trigger is fava beans, but a range of medicines can also cause problems, including certain antimalarials, some antibiotics such as sulfa drugs, and a few other oxidant drugs. A doctor or pharmacist familiar with your specific G6PD status can give you a complete list relevant to your situation.
Is G6PD deficiency dangerous all the time?
No, most people with G6PD deficiency feel completely normal most of the time and only experience problems after exposure to a specific trigger, which causes red blood cells to break down rapidly and can lead to fatigue, jaundice, or dark urine. Avoiding known triggers prevents most episodes.
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