Cordyceps sinensis is often referred to as the caterpillar fungus. It is actually a parasitic fungus that infects the catepillar of the moth, Hepialus armoricanus, killing the insect as it sprouts its fungal fruiting body. The dead insect then becomes the medicinal mushroom mycelium. Today, more practical harvesting methods have been developed upon sterile mediums.
Cordyceps is most commonly found in the highlands of China, Nepal, and Tibet; specific to habitat’s above 3500 feet elevation. It has been used in Traditional Chinese Medicine (TCM) for thousands of years. The Chinese view this particular fungus as both a general tonic and therapeutic agent in many bodily processes.
The Chinese have been using Cordyceps as a tonic for over two-thousand years. It is said to be a “yin nourishing” and “yang invigorating” tonic to balance the “Qi,” or one’s life force.  It was traditionally used to rebuild stamina after prolonged stress, for infertility and to increase libido, to improve kidney function, and to improve respiration.
Today, Cordyceps is still used according to TCM for asthma and other respiratory disorders, exercise enhancement, infertility, and immunomodulation. Studies have also shown it to be useful for high cholesterol, cancer, chemotherapy palliation, and for its anti-oxidant potential.
The active constituents in Cordyceps include polysaccharides - mannitol, sterols, and adenosine. Many supplements will standardize their product to the polysaccharides or adenosine, due to the research conducted on these more active constituents. The Cordyceps strain Cs-4 is regarded as the best, as it contains the highest amount of bioactive ingredients.
The whole mushroom can be used for therapeutic benefit. Often times, the mushroom is ground into a fine powder and put into capsules, made into a liquid tincture or liquid extract. Some studies have been performed using only the fruiting body, with conflicting results as to whether or not its efficacy is consistent.
Most studies conducted on Cordyceps have been carried out in animals, with a few notable trials completed on human subjects. Still, Cordyceps is highly regarded and widely used in both Eastern and Western cultures. Most of its therapeutic application is based upon the TCM theory and understanding of the mushroom. The following is a summary of the research that has been carried out, supporting uses of Cordyceps according to Traditional Chinese Medicine theory.
- Cordyceps may be a useful treatment for hormonal imbalances in both men and women. The traditional usage of Cordyceps for specific hormonal conditions, points to its effectiveness at improving libido, sexual performance, as well as being a legitimate treatment for infertility. Cordyceps was found to stimulate testosterone production and improve reproductive function in vivo.  It was also found to induce the production of estradiol, the estrogen made by the ovary. These findings conclude that it may be a viable treatment option for in vitro fertilization. 
- Cordyceps may be a useful adjunctive treatment for individuals with diabetes. It was found to lower blood sugar, and to decrease the increased urination rates and thirst associated with diabetes. 
- Cordyceps contains multiple constituents that are immunosuppressive. Certain studies imply that this fungus may be a useful treatment for cancers and autoimmune disease. However, more research is needed to confirm these preliminary findings. [5, 6]
- Cordyceps has also been shown to lower total cholesterol.  Cordyceps may be an effective treatment for persons with elevated cholesterol levels, heart disease, and atherosclerosis.
- Cordyceps has been shown to decrease fibrosis of the liver, and to prevent the development of cirrhosis from chronic liver injury.  As an alternative treatment, Cordyceps may be useful for many liver conditions.
- Cordyceps most effective use, may lie within its ability to combat fatigue and stress. It has been shown to increase time to fatigue, and to reduce stress, allowing for better performance in certain animal studies.  In fact, this use received world-wide attention in the early 90’s, as Chinese marathon runners on a Cordyceps-containing diet broke world long-distance records.
The typical daily dosage recommendation of Cordyceps is between 525 milligrams and 1000 milligrams, taken twice a day. Natural Cordyceps can be very expensive at these dosages, so many use the cultivated products. Some supplements offer a standardized product to insure greater efficacy, but often times lower dosages to save money on the manufacturing processes.
There have been no toxicities or deficiencies reported by the ingestion of Cordyceps available literature. Various dosages have proven safe. However, caution is advised for patients taking anti-coagulant or immuno-modulating drugs, and individuals preparing for surgery, due to Cordycep’s reported platelet aggregation-inhibitory activity.
1. Siu KM, Mak DH, Chiu PY, Poon MK, Du Y, Ko KM. Pharmacological basis of yin nourishing and yang invigorating actions of Cordyceps, a Chinese tonifying herb. Life Sci. 2004 Dec 10; 76(4): 385-395.
2. Huang YL et al. In vivo stimulatory effect of Cordyceps sinensis mycelium and its fractions on reproductive function in male mouse. Life Sci. 2004 Jul 16; 75(9): 1051-1062.
3. Huang BM et al. Upregulation of steroidogenic enzymes and ovarian 17-beta estradiol in human granulose-lutein cells by Cordyceps sinensis mycelium. Biol Reprod. 2004 May; 70(5): 1358-1364.
4. Lo HC, Tu ST, Lin KC, Lin SC. The anti-hyperglycemic activity of fruiting body of Cordyceps in diabetic rats induced by nicotinamide and streptozotocin. Life Sci. 2004 Apr 23; 74(23): 2897-2908.
5. Kuo YC, Tsai WJ, Shiao MS, Chen CF, Lin CY. Cordyceps sinensis as an immunomodulating agent. Am J Chin Med. 1996; 24(2): 111-125.
6. Kuo YC et al. Growth inhibitors against tumor cells in Cordyceps sinensis other than cordycepin and polysaccharides. Cancer Invest. 1994; 12 (6): 611-615.
7. Koh JH, Kim JM, Chang UJ, Suh HJ. Hypocholesterolemic effect of hot water extract from mycelia of Cordyceps sinensis. Biol Pharm Bull. 2003 Jan; 26(1): 84-87.
8. Liu YK, Shen W. Inhibitive effect of Cordyceps sinensis on experimental hepatic fibrosis and its possible mechanism. World J Gastroenterol. 2003 Mar; 9(3): 529-533.
9. Koh JH, Kim KM, Kim JM, Song JC, Suh HJ. Anti-fatigue and anti-stress effects of the hot water fraction from mycelia of Cordyceps sinensis. Biol Pharm Bull. 2003 May; 26(5): 691-694.