Most Common Reishi Mushroom Side Effects
Historically known as “the mushroom of mortality,” Ganoderma lucidum is the scientific name for the reishi mushroom. Reishi comes in all shapes, sizes, and flavors and has long been used to promote health and longevity in traditional Chinese medicine. Today, reishi mushroom capsules are one of the easiest and most popular ways to consume the supplement in western cultures.
Reishi Mushroom Side Effects
Reishi mushrooms are most well-known for their immune-boosting and cancer-fighting properties. Laboratory test-tube studies support the idea that they could be effective in fighting cancer and shrinking tumors. Additionally, in vitro and animal studies suggest that reishi may support the immune system.
However, few human studies have been done, and more is necessary before any final conclusions are made about the health benefits of reishi.
If you’re interested in using reishi to boost your overall well-being, you’ve probably wondered about the potential risks and side effects. Due to the limited body of research in humans, many side effects of reishi mushrooms remain unknown.
That said, reishi has been used for thousands of years, and few side effects have been recorded. We will explore potential reishi mushroom side effects and their risks in more detail below.
The Reishi Mushroom: A Superior Herb
The Chinese herbal system consists of a few thousand herbs. Within this system is a group of about a hundred “elite” herbs, known as the “superior herbs.” In Chinese herbalism, these unique herbs have also been named “tonic” herbs, and one of them is reishi.
To be classified as “tonic” in nature, herbs must meet specific qualifications. Here are the four requirements that need to be met:
- It must have been discovered over many centuries to have deep-rooted health-promoting properties that result in a long and healthy life.
- Must have no negative side effects when used appropriately over long periods of time.
- Must be believed to affect the psyche in a way that helps improve an individual’s state of emotional and spiritual well-being and happiness.
- They are considered to be superfoods, making up the fifth food group in the Chinese diet. This is a testament to their safety profile.
Classified as a superior herb, reishi is believed to be safe, non-toxic, and well-tolerated by most people. The mushroom has long been used in Chinese medicine as a nervous-system tonic. This means that it promotes balance and calmness in the whole body.
Potential Reishi Mushroom Side Effects
While reishi mushrooms are generally considered safe, effective, and well-tolerated, there are a few potential side effects to be aware of.
In some instances, mild digestive upset and skin rashes may occur. However, these side effects tend to disappear and usually only affect sensitive people with impaired immune systems.
A 2016 review of studies reported that reishi might help boost the immune system. However, the authors were reluctant to recommend the mushroom as a first response to cancer because some study participants reported side effects including upset stomach, skin rashes, and liver damage.
According to studies, reishi extract appears to be safe for up to one year when taken orally. Interestingly, though, there is a greater risk associated with using a powdered form of the reishi mushroom. In two separate case studies, individuals who previously used reishi mushrooms without any issue experienced adverse effects when switching to a powdered form.
Both of these individuals suffered from liver toxicity, a dangerous side effect that could result in death. There is also a report of a 49-year old man with non-Hodgkin’s lymphoma who experienced chronic diarrhea after long-term use of a powdered reishi mushroom extract.
Other potential side effects include:
- Dry mouth, throat, and nose
- Bloody stool
Generally, the side effects are minor and nothing to be alarmed by. However, if you do experience any of the above, it’s best to consult with your doctor to ensure you’re not having an allergic reaction or experiencing liver toxicity.
When to Avoid Reishi Mushrooms
Reishi contains a substance that may act as a blood thinner, meaning it could trigger nosebleeds, bloody stools, and easy bruising. Therefore, the mushroom should be avoided by those with bleeding disorders or liver disease.
As a result, you should stay away from reishi mushroom extract if you are using anticoagulants like warfarin or are due to have surgery as it could increase the risk of bleeding.
Additionally, reishi may lower blood pressure, which means it should be avoided if you are on antihypertensive medications. This is because it could cause hypotension, thereby triggering nausea, dizziness, fatigue, and blurry vision.
Also, avoid reishi if you’re taking immunosuppressants since it could stimulate immune responses. Researchers also advise those undergoing chemotherapy against the use of reishi because, in theory, it could make the chemotherapy drugs less effective.
Final Thoughts on Reishi Mushroom Side Effects
Reishi is a powerful medicinal mushroom that boasts an array of potential health benefits. Plus, it’s generally considered safe and non-toxic, with most people responding well to its effects.
However, there are a few potential negative side effects, and they may interfere with certain medications, which is why it’s important to exercise caution and speak to a doctor if you are concerned.
Research suggests that powdered forms of reishi extract pose a greater risk than other types, like capsules.
That said, research is still very limited, and more studies need to be done to determine a complete list of side effects and dangers.