Does Reishi Have Side Effects?

Reishi mushroom has been used safely in traditional medicine for thousands of years. Modern research generally confirms its safety profile, but like any supplement, it can cause side effects in some people. Understanding what to expect can help you make an informed decision about using Reishi.

Common Side Effects

The most frequently reported side effects of Reishi are mild digestive issues. Some people experience upset stomach, diarrhea, or dry mouth when they first start taking Reishi. These effects usually diminish as the body adjusts. Starting with a lower dose and gradually increasing can help minimize these initial reactions.

Skin Reactions

A small number of people report skin-related reactions to Reishi, including itching or rash. These reactions are relatively rare but can occur, particularly in those with mushroom sensitivities. If you experience skin reactions, discontinuing use typically resolves the issue.

Dizziness and Headaches

Some users report occasional dizziness or headaches, particularly when first starting Reishi supplementation. These effects are usually temporary and mild. Staying well-hydrated and taking Reishi with food may help reduce these symptoms.

Blood-Related Considerations

Reishi may have blood-thinning properties and could potentially lower blood pressure. While this is generally considered beneficial, it can be problematic for people already on blood thinners or blood pressure medications. Anyone with bleeding disorders should consult their healthcare provider before using Reishi.

Long-Term Use

Most studies on Reishi have looked at short to medium-term use. While traditional use suggests long-term safety, some practitioners recommend taking periodic breaks from supplementation. There have been rare reports of liver issues with very high doses over extended periods, though these cases are not well-documented.

Who Should Be Cautious

Pregnant or breastfeeding women should avoid Reishi due to lack of safety data. People scheduled for surgery should stop taking Reishi at least two weeks beforehand due to its potential blood-thinning effects. Those with autoimmune conditions should consult a healthcare provider, as Reishi can affect immune function.

The Bottom Line

Reishi is generally well-tolerated by most healthy adults when taken at recommended doses. Side effects, when they occur, tend to be mild and temporary. However, individual responses vary, and certain groups should exercise caution. Starting with a low dose and monitoring your response is the safest approach.