Lion's Mane Mushroom Side Effects: Risks, Precautions, and Benefits

Lion's Mane Mushroom Side Effects: Risks, Precautions, and Benefits

Many people are interested in lion's mane mushrooms these days. 

But before you start incorporating it into your diet, it's important to understand the potential side effects as well.

Lion's mane is a type of mushroom that is commonly found in Asia, Europe, and North America. It has a distinct appearance that looks like white icicles or fur, hence the name lion's mane.

It has been studied for its ability to support cognitive function by helping new brain cells grow, boost immune health, and even aid in digestion. It's also been shown to have anti-inflammatory and antioxidant properties.

While these potential benefits are exciting, it's crucial to also consider the potential side effects of lion's mane. 

Just like any supplement or medication, it's possible to experience negative reactions. That's why understanding the potential risks is important before adding it to your routine.

What is Lion's Mane?

Lion’s mane is a type of mushroom that has long, shaggy spines that resemble the mane of a lion - hence the name! It's also known as "yamabushitake" in Japanese and "hóu tóu gū" in Chinese.

This funky-looking mushroom has actually been used for centuries in traditional Chinese and Japanese medicine to treat a variety of ailments.

In recent years, scientific research has started to explore the potential health benefits of lion's mane. Some studies suggest that it may be able to stimulate nerve growth and support cognitive function

It's also been shown to have anti-inflammatory properties and may even help lower cholesterol levels.

Lots of people also find it beneficial for managing ADHD symptoms. 

While more research is needed to fully understand the effects of lion's mane, its long history of use in traditional medicine and promising early research make it an interesting mushroom to keep an eye on!

Potential side effects of lion's mane

While it's generally considered safe for consumption, there are some risks associated with taking it as a supplement.

One of the potential risks is an allergic reaction. If you're allergic to other types of mushrooms, you may also be allergic to lion's mane. It's also possible to experience stomach discomfort or diarrhoea if you take too much.

Lion's mane may also interact with certain medications, such as blood thinning medication, so it's especially important to check with your doctor if you're taking any prescription drugs.

Common side effects of lion's mane

While side effects are not commonly reported after taking lion’s mane, when they are reported, these are the most common:

  1. Upset stomach: Some people have reported experiencing stomach discomfort or even diarrhoea after taking lion's mane. 
  1. Skin rash: A few users have reported developing a rash after taking lion's mane.
  1. Headache: While rare, some people have reported experiencing headaches after taking lion's mane.

  1. Panic attacks: A very small percentage of people who take lion’s mane experience feelings of panic and some even have full blown panic attacks. It’s not understood why this happens, but may be linked with the mushroom’s neurogenerative properties. 
  1. Sleep problems and overactive mind: Some people also experience problems getting to sleep due to an overactive mind when they take lion’s mane.

It's important to note that lion’s mane side effects are uncommon, generally mild and don't last very long. In most cases, they go away on their own within a few hours or days. If you experience any of these side effects, it's best to stop taking lion's mane and see if they go away.

Severe lion’s mane side effects

Alarmingly, a subreddit called r/LionsManeRecovery, that was established in 2022, presents some scary reports of severe negative effects from lion’s mane.

Most notably, these side effects include intense headaches, panic attacks, sleep problems and feelings of derealisation/depersonalisation. Some even claim that lion’s mane causes symptoms of psychosis and other mental health disorders. 

The subreddit, which has 1.6k members at the time of writing this article, offers support for those dealing with the “devastating and life-changing” side effects of lion’s mane mushroom.

However, it must be pointed out that these side effects are only reported by a very small percentage of lion’s mane consumers, and there is little consensus on how lion’s mane might cause these effects - or if they are even caused by lion’s mane to start with.    

Some people have suggested these negative effects of lion's mane could be down to heavy metals (lead, mercury) present in some supplements, while others believe that those suffering are attributing the effects to lion’s mane when it’s more likely another condition such as long covid. 

Whatever is causing these symptoms, if you experience any headaches or feelings of panic when taking lion’s mane, it’s probably best to stop taking it to see if the symptoms stop. 

Lion’s mane has the power to boost brain cell growth. This could have positive or negative effects on a person’s mental state, depending on many factors. 

How to reduce risk of lion’s mane side effects

To minimise the risk of side effects of lion's mane, there are a few things you can do.

- Don’t overdo it: Firstly, it's important to follow the recommended dosage guidelines - 400mg of extract per day is a good starting point. Taking too much lion's mane can increase the risk of side effects, so it's best to start with a small dose and work your way up slowly.

- Check your current medication: Be mindful of potential interactions with other medications or supplements you may be taking. Lion's mane may interact with certain drugs, like blood thinning or blood sugar lowering medication, so it's important to check with a health professional before taking it if you're currently on medication.

- Find a quality brand: When buying lion's mane supplements, it's important to use high-quality products that have been tested for heavy metal, and to only buy from reputable brands, such as these.

- Observe your reaction: It's important to pay attention to any changes in your body or symptoms that may appear after taking lion's mane. If you experience any side effects, such as a headache, anxiety, stomach discomfort or a rash, it's best to stop taking lion's mane.

Be sure to do your research on lion’s mane (or any supplement, for that matter). Lion’s mane mushroom can be a very useful tool, but for some it may cause problems. 


In conclusion, lion's mane is a fascinating mushroom that has been shown to offer several potential benefits, including supporting cognitive function, boosting immune health, and aiding digestion, among other things. 

However, like any supplement or medication, there are potential risks and side effects to consider. Some of the possible side effects include an allergic reaction, stomach discomfort or diarrhoea, and interactions with certain medications. 

There are also reports of uncommon side effects, such as headaches, panic attacks, and insomnia. 

Overall, lion's mane is considered safe for consumption for most people, but it's crucial to understand the potential risks and side effects before adding it to your routine. Remember, always follow the recommended dosage guidelines and start with a small dose to minimise the risk of side effects.

See our range of independently tested, super high-quality lion's mane extracts here

Or sign up to our newsletter at the bottom of the page for more Mushies magic...

Related Posts


> The subreddit, which has 1.6k members at the time

Now 6k and counting… How many more lives needs to be devastated before the world will know that this substance is highly dangerous?


After 2 weeks @ 500 mg / day I hab panic attack and headacke

Audree Simard

Leave a comment

Please note, comments need to be approved before they are published.