How Much Lion’s Mane Is Too Much?

Most people should not exceed 3,000mg (3g) of Lion’s Mane per day.

This is the highest dose commonly used in clinical research and is considered safe and effective. Taking more than 3g may increase the risk of side effects like nausea or digestive upset, without providing additional benefit.

Mitesh Desai, Nutritionist at Landy’s Chemist, adds: “Lion’s Mane mushroom supplements are powerful, but more isn’t always better. At high doses, you risk overstimulating the nervous system. I recommend increasing gradually and always staying within clinically supported ranges.”

What Is the Recommended Daily Dosage of Lion’s Mane?

The recommended daily dosage of Lion’s Mane mushroom is between 500mg and 3,000mg, ideally taken in divided doses - such as morning and afternoon with food to support absorption and reduce the chance of digestive upset.

A 2010 study in Biomedical Research showed that 1,000mg daily significantly improved memory in older adults without side effects. This dosage is commonly used in Lion’s Mane supplements sold in the UK.

Is Lion’s Mane Toxic in High Doses?

No, Lion’s Mane is not considered toxic - even at higher doses.

However, that doesn’t mean more is better. However, exceeding the upper threshold may overstimulate nerve growth factor (NGF), increasing the risk of side effects - particularly in people with gut or neurological sensitivities.

Nerve Growth Factor (NGF) is a natural substance in the body that helps your nerves grow, stay healthy, and repair themselves when damaged.

Common Side Effects Above 3g Daily:

• Nausea or bloating
• Loose stools or diarrhoea
• Headaches
• Rare allergic responses

These typically subside when intake is reduced.

Mitesh Desai explains: “Excessive Lion’s Mane can make the nervous system more reactive. This is especially true for people with sensitive digestion or pre-existing neurological imbalances.”

What Happens if You Take Too Much Lion’s Mane?

Symptoms of excess may include:

• Gastrointestinal discomfort (bloating, loose stools, nausea)
• Cognitive side effects like brain fog or tension headaches
• Allergic-type reactions in rare cases, particularly among those with fungal allergies

There’s no clinical data showing long-term toxicity in humans, but it’s important not to exceed label guidance, especially if combining with other nootropic or mushroom supplements.

Is There Any Benefit to Taking More Than 3g?

No. Research does not support enhanced Lion’s Mane benefits above 3,000mg daily.

Based on current clinical research, human studies on Lion's Mane (Hericium erinaceus) typically utilise daily dosages up to 3 grams. There is limited evidence to suggest that higher doses provide additional benefits, and some studies have not demonstrated significant improvements at these higher levels.

How to Take Lion’s Mane Safely

To maximise benefit and reduce side effects:

• Start with 500–1,000mg/day
• Increase gradually based on how your body responds
• Always take the supplement with a meal
• Consider cycling: e.g) 5 days on, 2 off, or monthly breaks
• Use a standardised, organic, high quality extract. Shop from our range of trusted Lion’s Mane Supplements here 

Final Verdict: Take 500mg-3,000mg of Lion’s Mane per day for best results.

Higher doses do not offer extra benefit and could increase side effect risk. Choose a trusted supplement, take it consistently, and stay within this range to support memory, focus, nerve repair, and cognitive performance - without unnecessary risks.

Sources

1. What the Evidence Says About Lion’s Mane Mushroom for Patients With Cancer | Oncology Nursing Society
2. Medicinal Mushrooms: Bioactive Compounds, Use, and Clinical Trials - PMC
3. Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake - PubMed
4. Mycotherapy: Potential of Fungal Bioactives for the Treatment of Mental Health Disorders and Morbidities of Chronic Pain

This article is for informational purposes only and is not a substitute for medical advice. Consult your doctor or healthcare provider before starting any supplements, treatments, or remedies. Ensure a varied and balanced diet and a healthy lifestyle before considering supplements. Supplements should not replace a balanced diet.