Reishi mushroom (Ganoderma lucidum) may help lower blood pressure, although the evidence is weak. You can also take a tincture of this mushroom extract. Reishi may interact with other medications and increase the risk of bleeding. There really isn't a definitive answer as to whether Reishi mushroom lowers blood pressure or not.
Lingzhi doesn't seem to affect blood pressure in normal people or in people with slightly higher blood pressure, although it does seem to help people with very high blood pressure. Studies show mixed results, but reishi mushrooms may lower blood pressure in some people. If you have low blood pressure or use medications to lower it, talk to your doctor before taking reishi mushrooms. They can also increase bleeding during surgery, so doctors recommend stopping consuming reishi mushrooms at least two weeks before the scheduled surgery.
Because reishi mushrooms can stimulate the immune system's response, they can worsen symptoms in people who take immunosuppressive medications to treat conditions such as rheumatoid arthritis, inflammatory bowel disease, or psoriasis. Reishi mushrooms can lower blood sugar levels, so taking them together with medications to treat diabetes can cause your blood sugar level to drop too low. While more research in humans is needed, laboratory studies show that reishi mushrooms also stimulate a type of white blood cells called “natural killer cells” that attack abnormal cells, including cancerous ones. Reishi mushrooms can also help regulate the body's testosterone levels, which promotes good energy levels.
However, some people with high blood pressure reported that their blood pressure had dropped after using Reishi mushrooms. Reishi mushrooms are considered safe for most people and, throughout their long medicinal history, there is no evidence of toxic effects. There isn't enough information to determine if reishi mushrooms are safe for pregnant or breastfeeding women. Studies show that reishi mushrooms can increase the number of white blood cells in the body and improve their function.
You can eat fresh reishi mushrooms and they are also sold as nutritional powder, dietary supplement, and tea.