Can I take Reishi and Shiitake together?

Why this happens

Both reishi and shiitake contain compounds that have 'antiplatelet' effects. This means they make the tiny cells in your blood (platelets) less 'sticky', which slows down the formation of blood clots. Taking them together creates an additive effect, further thinning the blood.

What you should do

It is usually fine to take these together in standard food or supplement amounts if you are healthy. However, you should stop taking both at least two weeks before any scheduled surgery. If you take blood-thinning medications (like warfarin, aspirin, or clopidogrel), speak to your doctor before combining these supplements. Watch for unusual bruising, nosebleeds, or bleeding gums.

Important precautions

Bleeding disorders or surgery

These supplements may slow blood clotting and increase the risk of bleeding. You must stop taking these at least 2 weeks before any scheduled surgery. Use with caution if you are taking blood-thinning medications like warfarin or aspirin.

Diabetes

These supplements can lower blood sugar levels. If you are taking insulin or other diabetes medications, monitor your blood sugar closely as your dose may need adjustment to prevent hypoglycaemia (dangerously low blood sugar).

Auto-immune conditions (e.g., multiple sclerosis, lupus, rheumatoid arthritis)

Reishi can increase immune system activity, which may worsen the symptoms of autoimmune diseases. Avoid use if you have these conditions.

Low blood pressure (Hypotension)

Reishi may lower blood pressure. If you already have low blood pressure or take medication to control high blood pressure, they could cause your blood pressure to drop too low.

Shiitake dermatitis

Eating raw or undercooked shiitake mushrooms can cause a severe, itchy skin rash known as 'flagellate dermatitis' that looks like whip marks. Ensure mushrooms are thoroughly cooked.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol when taking medicinal mushrooms. Both alcohol and certain compounds in these mushrooms are processed by the liver; combining them may increase the strain on your liver or alter how the supplements are metabolised.

Caffeine

Reishi is often used for its calming effects, while caffeine is a stimulant. Consuming high amounts of caffeine may counteract the intended relaxing effects of the supplement.

General Food Intake

These medicinal mushrooms contain complex polysaccharides (beta-glucans). For the best absorption, it is often recommended to take them on an empty stomach, at least 30 minutes before a meal, or with a small amount of Vitamin C (such as a small glass of orange juice) which may help the body absorb the active compounds.

Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.