What Ginseng does
The biochemical mechanisms of ginseng remain unclear, although there is extensive literature that deals with its effects on the brain (memory, learning, and behavior), neuroendocrine function, carbohydrate and lipid metabolism, immune function, and the cardiovascular system. Reports are often contradictory, perhaps because the ginsenoside content of ginseng root or root extracts can differ, depending on the species, method of extraction, subsequent treatment, or even the season of collection. Ginseng does have the potential to help with blood sugar levels.

Availability of Ginseng product
Countless varieties and dosages of ginseng products are available. One option is to buy a ginseng product that has a standardized extract of 3 to 7 percent ginsenosides. Use 100 mg of this extract in the morning a few times a week. You may require 500 to 2,000 mg of he dried ginseng root to feel the effects. It’s best to cycle the use of ginseng. For instance, you can take ginseng for two or three weeks and then take off a few weeks.

Ginseng side effects
Insomnia is a common side effect from ginseng overuse, particularly Asian ginseng—especially when it’s combined in high doses with other herbs or nutrients that cause alertness. Althea, a 38 year-old owner of a garden shop in Maui, says, "I took ginseng that was recommended by a Chinese physician for fatigue. I took the ginseng for two weeks. I felt really better emotionally, mellow, and with increased energy. Then I started to have increased sleep problems and insomnia. I went three days being so mentally and physically overstimulated that I hardly got any sleep. I imagine this is what being on "speed" must feel like. I stopped taking the ginseng and within two days I slowly returned to my normal state."
   This story confirms my recommendations that dosages of nutrients and herbs have to be constantly evaluated since they can build up in the system.
   Patients being treated with the blood-thinning drug Coumadin (warfarin) should probably avoid using ginseng, since ginseng seems to reduce the drug's effects. Ginseng use for two weeks was tied to a significant reduction in the INR, meaning that the blood was now less thin and more prone to clotting.

American ginseng and diabetes
American ginseng modulates pancreatic beta cell activities.
Chin Med. 2007 Oct 25.
Recent studies show that American Ginseng, Panax quinquefolius, increases insulin production and reduces the death of pancreatic beta cells. American Ginseng influences immune fucntion and mitochondrial function through various factors. Clinical studies show that American Ginseng improves postprandial glycemia in type 2 diabetic patients.

Ginseng and exercise performance
Ginseng supplementation does not change lactate threshold and physical performances in physically active Thai men.
J Med Assoc Thai. 2007 Jun;90(6):1172-9. Kulaputana O, Thanakomsirichot S, Anomasiri W. Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
Ginseng has been one of the most popular herbs said to improve human exercise performance. Unclear and anecdotal information is known about the effect of ginseng on lactate threshold and aerobic performance in humans. The purpose of the present study was to investigate the effect of ginseng supplementation on lactate threshold in physically active young men. Sixty men from the Naval Medical Corps, Royal Thai Navy, aged 17- 22 years old, were randomized into either the ginseng or placebo group. The ginseng group took 3 grams of 100% ginseng orally, while the placebo group took an equal amount of lactose powder each day, for 8 weeks. Daily administration of 3 g of ginseng for an 8-week period did not improve LT nor did it affect physical performances. Therefore, ginseng supplementation did not exert an ergogenic property on aerobic fitness enhancement in well-fit individuals.

Panax Ginseng as impotence herb
Effects of tissue-cultured mountain ginseng (Panax ginseng CA Meyer) extract on male patients with erectile dysfunction.
Department of Urology, School of Medicine, Kyung Hee University, Seoul 134-727, Korea.
Korean ginseng and mountain ginseng (Panax ginseng CA Meyer) are important traditional herbal plants whose ginsenosides are generally accepted as serving to improve sexual functions, such as penile erection. We investigated the effects of tissue-cultured mountain ginseng extract on male patients with impotence. A double-blind, placebo-controlled study was conducted with 143 patients experiencing impotence. Over the course of 8 weeks, one group took 1 000 mg of ginseng extract twice a day, and the other group took 1 000 mg of placebo twice a day. Erectile function and overall satisfaction scores after medication were significantly higher in the ginseng extract group than in the placebo group. Erectile function of patients in the ginseng extract treated group significantly improved, suggesting that ginseng extract could be utilized as an impotence herb in male patients.

Ginseng Summary
Many people who take ginseng find this herb to be a good overall energizer and cognitive enhancer. Due to the tremendous variety of ginseng products sold, it is difficult to give definite dosage recommendations. You could certainly try a few ginseng products to see which one(s) give you a positive effect. In practical and simple terms, Asian ginseng raises body temperature and is more stimulating while American ginseng is more calming. The effects of Siberian ginseng fall somewhere between these two. See information on panax ginseng.