Agaricus blazei Murill is a mushroom from Brazil, also grown in Japan under the name Himematsutake. It supplies beta-glucans and other polysaccharides. Those compounds draw attention for how they influence the immune system.
People take agaricus extract or powder in capsules, tablets, or loose powder. They often take it with meals so the body can use it better. Follow the dosing directions on the product label since potency varies from one brand to another.
Anyone with an autoimmune condition needs to talk to a doctor before starting agaricus. The mushroom may lower blood sugar, so check glucose regularly if you have diabetes or take blood-sugar medicine. Organ transplant recipients and people on drugs that suppress the immune system should be careful. Mild stomach upset shows up in some users.