Cordyceps has not been shown to treat or prevent cancer.
Cordyceps, used in traditional Chinese medicine, contains a fungus that grows on caterpillar larvae; both are contained in the product and both are consumed. Cordyceps has not been studied extensively in the laboratory, but existing studies show that it stimulates many different immune cells when directly applied to them in a test tube.
It is not known if cordyceps stimulates the immune system in humans. Animal studies suggest that cordyceps can stimulate progesterone production and reduce kidney toxicity from harsh medications, but how cordyceps exerts these effects, or whether this would occur in humans, is unknown. Studies in kidney transplant patients suggest cordyceps can help improve kidney function, but more study is needed.
Cordyceps has blood-thinning properties. It may also reduce blood sugar levels.
To stimulate the immune system
Laboratory studies show that cordyceps stimulates several aspects of the immune system, but it is not known whether this effect occurs in the human body.
To treat kidney failure
A few studies show that cordyceps may help improve renal function.
You have a myelogenous type cancer such as AML or CML: Cordyceps has been shown to increase proliferation of red blood cell precursor cells. These cells arise from the same lineage as the cells that cause myelogenous cancers.
You take insulin or other blood-glucose lowering medications: Cordyceps may have an additive hypoglycemic effect; blood glucose should be monitored.
You take a drug that has “blood thinning” activity: Cordyceps may increase the risk of bleeding.
Cordyceps includes the fungus that grows on the larvae of the caterpillar Hepialus armoricanus Oberthuer. Both are contained in the product and both are consumed. Cordyceps is used for a wide range of conditions including fatigue, sexual dysfunction, coughs, and as an adaptogen or immune stimulant. In vitro and animal studies show antitumor (10)(11)(14), radioprotective (12), antiplatelet (19) and antidiabetic effects (15)(16). In addition, cordyceps enhances recovery of mice with taxol-induced leukopenia (13) and increases the cytotoxicity of cisplatin in non-small cell lung cancer cells (17).
Cordyceps products improved renal function and reduced nephropathy in renal transplant patients (18)(21)(23) and diabetes patients with renal insufficiency undergoing coronary angiography (25). However, a systematic review determined the evidence for its utility as an adjuvant immunosuppressive agent in renal transplant recipients is limited and that more study is needed (26). Studies on exercise performance in healthy subjects yielded mixed results (22)(24).
Cordyceps may increase the adverse effects of antidiabetic or anticoagulant/antiplatelet drugs. Animal studies showed proliferation of progenitor red blood cells with cordyceps (8). Therefore, it should not be used by those with myelogenous type cancers. Cordyceps also stimulated testosterone production in mice (9). Whether it exerts similar effects in humans is not known.
Strength and stamina
Cordyceps stimulates the number of T helper cells, prolongs the survival of lymphocytes, enhances TNF-alpha and interleukin 1 production, and increases the activity of natural killer cells in cultured rat Kupffer cells (3). Enhanced proliferation of erythroid progenitor cells in the bone marrow of mice is also shown (8). One study suggests that cordyceps can stimulate progesterone production in animal cells (5). Another study shows that cordyceps may be effective against tumor celIs by down-regulating MHC class II antigen expression (7). In addition, anecdotal data suggest reduction of cyclosporin and aminoglycoside-induced renal toxicity, although the mechanism of action is not known (4). Cordycepin, an active constituent in cordyceps, inhibits collagen-induced platelet aggregation by lowering calcium ion and thromboxane A2 activities (19).
Hypoglycemics / Insulin: Cordyceps may have additive hypoglycemic effects (16)(17). Anticoagulants / Antiplatelets: Cordyceps inhibits platelet aggregation and may increase the effects of these drugs (19).
Huang KC. The Pharmacology of Chinese Herbs, 2nd ed. Boca Raton: CRC Press; 1999.