Functional mushrooms are rapidly gaining attention in the wellness world—and for good reason. From Lion’s Mane for sharper focus to Reishi for stress relief, these powerful fungi offer a wide range of potential health benefits. But like any supplement, they aren’t without risks. While most people tolerate functional mushrooms well, some may experience side effects, and it’s important to understand these before adding them to your routine.
In this guide, we’ll break down the most common side effects of functional mushrooms, highlight who should approach them with caution, and share practical tips for reducing risks. Our aim is to give you a clear, evidence-based perspective so you can make confident, informed choices about your health. At Vital Pour, we believe in transparency—and that means talking honestly about both the benefits and the possible downsides of natural remedies.
Common Functional Mushroom Side Effects
While generally considered safe, functional mushrooms can cause side effects in some individuals. These are typically mild and often resolve on their own, but it's important to be aware of them. The most commonly reported side effects include:
- Digestive Upset: This is the most common side effect and can include bloating, gas, stomach pain, and nausea. It's often caused by the high fiber content of mushrooms and can sometimes be mitigated by starting with a lower dose and gradually increasing it.
- Allergic Reactions: While rare, some people may have an allergic reaction to certain mushrooms. Symptoms can range from a mild skin rash to more severe reactions like difficulty breathing and swelling of the throat. If you have a known allergy to mold or other fungi, you may be at a higher risk.
- Changes in Blood Pressure and Blood Sugar: Some mushrooms, like Reishi, can lower blood pressure and blood sugar levels. This can be beneficial for some people, but it can also be dangerous for those who are already taking medication for these conditions. It's crucial to monitor your levels closely and consult with your doctor if you have any concerns.
- Increased Risk of Bleeding: Certain mushrooms, such as Reishi and Turkey Tail, can have a blood-thinning effect. This can increase the risk of bruising and bleeding, especially in individuals with bleeding disorders or those who are taking blood-thinning medications.
Individual Mushroom Safety Profiles
While there are general side effects to be aware of, each functional mushroom has its own unique safety profile. Here is a breakdown of the most common mushrooms and their specific side effects and contraindications:
Reishi (Ganoderma lucidum)
- Side Effects: Dizziness, dry mouth, itching, nausea, stomach upset, rash.
- Contraindications: Pregnancy/breastfeeding, bleeding disorders, low blood pressure, upcoming surgery.
- Drug Interactions: Blood pressure medications, blood thinners, diabetes medications.
Turkey Tail (Trametes versicolor)
- Side Effects: Gastrointestinal issues, constipation, cold/flu symptoms, low blood pressure, low blood sugar, low white blood cell count, heart palpitations, rash.
- Contraindications: Pregnancy/lactation.
- Drug Interactions: Chemotherapy (consult with oncologist).
Lion's Mane (Hericium erinaceus)
- Side Effects: Generally well-tolerated, but some reports of mild digestive upset.
- Contraindications: None well-documented, but caution is advised for those with mushroom allergies.
Cordyceps (Cordyceps militaris)
- Side Effects: Generally well-tolerated, but some reports of mild digestive upset.
- Contraindications: Autoimmune conditions (may stimulate the immune system).
Caption: Mushroom compounds like ergothioneine interact with multiple body systems, which is why side effects can vary widely between individuals.
Who Should Avoid Mushroom Supplements?
While functional mushrooms are safe for most people, there are certain individuals who should exercise caution or avoid them altogether. This includes:
- Pregnant or Breastfeeding Women: There is not enough research on the safety of functional mushrooms during pregnancy or lactation. It is best to err on the side of caution and avoid them.
- Individuals with Bleeding Disorders: As mentioned earlier, some mushrooms can have a blood-thinning effect. If you have a bleeding disorder or are taking blood-thinning medication, it is important to consult with your doctor before taking any mushroom supplements.
- People with Autoimmune Conditions: Some mushrooms, like Cordyceps, can stimulate the immune system. This can be problematic for individuals with autoimmune conditions such as rheumatoid arthritis, lupus, or multiple sclerosis.
- Those with Mushroom Allergies: If you have a known allergy to mushrooms or mold, it is best to avoid functional mushroom supplements.
How to Minimize Side Effects
If you are new to functional mushrooms, there are several steps you can take to minimize the risk of side effects:
- Start with a Low Dose: Begin with a small dose and gradually increase it over time. This will give your body a chance to adjust and can help to prevent digestive upset.
- Choose a Reputable Brand: Not all mushroom supplements are created equal. Look for brands that use high-quality, organic mushrooms and provide third-party testing for purity and potency. VitalPour is committed to providing the highest quality mushroom supplements on the market.
- Listen to Your Body: Pay attention to how you feel after taking a mushroom supplement. If you experience any adverse effects, stop taking it and consult with your doctor.
- Consult with a Healthcare Provider: Before starting any new supplement, it is always a good idea to talk to your doctor or a qualified healthcare provider. They can help you to determine if functional mushrooms are right for you and can provide guidance on dosage and potential interactions.
The Takeaway
Functional mushrooms can be a powerful tool for supporting your health and well-being. However, it is important to be aware of the potential side effects and to take steps to minimize your risk. By starting with a low dose, choosing a reputable brand, and listening to your body, you can safely enjoy the many benefits that these incredible fungi have to offer.
For more information on the benefits of functional mushrooms, be sure to check out our articles on The Health Benefits of Mushroom Coffee and Reishi Mushroom Benefits for Sleep and Stress Relief.
References
- WebMD. (n.d.). Reishi Mushroom: Uses, Side Effects, and More. Retrieved from https://www.webmd.com/vitamins/ai/ingredientmono-905/reishi-mushroom
- Gaia Herbs. (2022, December 26). Turkey Tail Mushroom Side Effects and Precautions. Retrieved from https://www.gaiaherbs.com/blogs/seeds-of-knowledge/turkey-tail-mushroom-side-effects
- Forbes Health. (2023, September 5). Mushroom Supplements: Benefits, Types and Potential Risks. Retrieved from https://www.forbes.com/health/supplements/mushroom-supplement/
- GoodRx. (2023, November 7). Do Functional Mushrooms Help Pain, Inflammation, and Sleep? Yes!. Retrieved from https://www.goodrx.com/well-being/supplements-herbs/functional-mushrooms
