What ginseng root 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. It does have the potential to help with blood sugar levels and does increase energy.

Drug metabolism
Ginseng doesn't seem to alter how most prescription and over-the-counter drugs are absorbed or metabolized in the body, unlike other herbs such as Saint John's wort.

Laboratory and Human studies
Let’s examine some of the studies done with ginseng.

Adaptogen effect?
Adaptogen is a term coined to loosely define certain herbs that help improve energy, vitality, mood, wellbeing, etc. Users of this term imply that these adaptogens are healthy to take and may prolong life, although there usually is little research to back up these claims. We prefer not to use the term adaptogen since it does not have a reliable scientific definition. Most who take ginseng notice more energy, vitality, sexual enjoyment, and mental clarity.

Anti-inflammatory
Allan Lau of the University of Hong Kong identified seven ginseng constituents -- ginsenosides -- which can help reduce inflammation. "The anti-inflammatory role of ginseng may be due to the combined effects of these ginsenosides, targeting different levels of immunological activity, and so contributing to the diverse actions of ginseng in humans," Allan Lau said in a statement in 2009.

Antioxidants, and Lipids
The administration of several grams of ginseng daily increases the ability of the body to maintain its antioxidant status. Furthermore, lipid levels such as LDL cholesterol are lowered.

Effects of Panax ginseng extract on lipid metabolism in humans.
Pharmacol Res. 2003.
The purpose of this study was to examine the effects of Panax ginseng extract (PGE) on lipid metabolism in humans by measuring cholesterol, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT). Serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and plasma MDA levels were decreased by administration of PGE for 8 weeks (6g per day), however, high density lipoprotein (HDL) was increased. Administration of PGE increased SOD and CAT activities while decreased MDA level indicating that antioxidant potential of PGE might induce hypolipidemic effect as one of action mechanism.
       
Cognitive functioning
Various tests of mental performance were carried out in a group of sixteen healthy male volunteers given a standardized preparation of Asian ginseng (100 mg twice a day for twelve weeks of a product called G 115). A similar group was given identical placebo capsules under double-blind conditions. A favorable effect of ginseng was observed in attention, mental arithmetic, logical deduction, and auditory reaction time.         
   Researchers at the Cognitive Drug Research Ltd., Beech Hill, Reading, in the United Kingdom evaluated the effects of a Ginkgo biloba/ginseng combination on cognitive function. The study lasted ninety days and was performed in a double blind, placebo-controlled manner with sixty-four healthy volunteers (aged 40 to 65 years) who had mild fatigue and low mood. The treatment was well tolerated by all volunteers. There were improvements noted in memory and overall cognitive functioning.
   Ginseng root saponin at a dose of 50 mg three times a day was given for two months to 358 middle and old age individuals. The results showed that the herb improved memory and immunity.

Impotence and sex enhancement
Ginseng has been touted as a sex stimulant for countless generations. it has compounds that enhance nitric oxide production which helps dilate blood vessels. This may partially account for the improvement in impotence or erectile dysfunction.

A double-blind crossover study evaluating the efficacy of korean red ginseng in patients with erectile dysfunction: a preliminary report.
J Urol. 2002.
PWe investigated the efficacy of Korean red ginseng for erectile dysfunction using the International Index of Erectile Function, RigiScan (UroHealth Systems, Laguna Niguel, California), hormonal levels and penile duplex ultrasonography with audiovisual sexual stimulation. A total of 45 patients with clinically diagnosed erectile dysfunction were enrolled in a double-blind, placebo controlled, crossover study (8 weeks on treatment, 2 weeks of washout and 8 weeks on treatment) in which the effects of Korean red ginseng and a vehicle placebo were compared using multiple variables. The ginseng dose was 900 mg. 3 times daily. Mean International Index of Erectile Function scores were significantly higher in patients treated with Korean red ginseng than in those who received placebo. Scores on questions 3 (penetration) and 4 (maintenance) were significantly higher in the ginseng than in the placebo group. In response to the global efficacy question 60% of the patients answered that Korean red ginseng improved erection. Among other variables penile tip rigidity on RigiScan showed significant improvement for ginseng versus placebo. Our data show that Korean red ginseng can be as effective alternative for treating male erectile dysfunction.

Passion Rx benefit
This natural sexual enhancer is ideal for Men and Women who are not enjoying sex as much as before, and also for those who wish to enhance a normal sex life to new heights of Passion. After years of research, renowned herbal expert and bestselling author Dr. Ray Sahelian, M.D., author of Natural Sex Boosters, has formulated a brand new product that has a powerful effect on sex drive, passion, desire, and performance. "Passion Rx works. My patients appreciate the enhancement in pleasure and urge that they notice within a few days."
   Passion Rx has a combination of more than a dozen different sexual enhancing herbs, mixed in the right combination, extract potencies, and dosages to provide all day sexual enhancement. The herbs in Passion Rx include ashwagandha, catuaba herb, cnidium herb, muira puama herb, tribulus herb, tongkat ali herb, and yohimbe herb. Tongkat ali is a potent aphrodisiac, more so than ginseng root.

Quality of life, wellbeing
The aim of this study was to compare the quality-of-life parameters in subjects receiving multivitamins plus ginseng with those found in subjects receiving multivitamins alone. The study was randomized and double-blind, and it involved 625 patients of both sexes divided into two groups taking one capsule per day for twelve weeks. Group A received vitamins, minerals, trace elements and ginseng extract while group B received vitamins, minerals and trace elements only. By the end of the study, both the group-A and the group-B tested positively on a questionnaire evaluating quality of life, but Group A had a higher score.  
      
Availability over the counter
Countless varieties and dosages of ginseng 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 Revitalizer, Planetary Herbals
Ginseng is a legendary energy enhancer first written about in the Sui Dynasty of China ( 580 - 601 A.D. ). In traditional Chinese herbalism it is rarely used alone, but rather is combined with herbs considered to assist and augment its tonifying actions. Planetary Herbals Ginseng Revitalizer is based on a classic formula that has been in continued use since 1078 A.D. This dynamic combination is designed to support energy levels without the use of stimulants.

Ginseng side effects, safety
Insomnia is a common side effect from 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 our 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.

Before I start to use ginseng I would like to request for your advice. I am heart patient - I went through angioplasty two years back and taking medicine to control blood pressure and blood thinner every day. Is this herb Ok for me to take? If yes, which type and what should doses and so on. I am 54 years old and half retired person.
   Ginseng, and many herbs that have a stimulant nature, are not advised for heart patients, at least not in high dosages. See heart disease for more info.

Q. I took ginseng 2 days ago and I still have horrible side effects, massive anxiety, panic attacks, exhaustion, pink lips, everything is aching, it is absolutely horrible. I have to take antidepressants and Valium here with my doctor in the UK.
   A. The side effects from herbs often go away after a couple of days, at most 4 or 5 days, rarely lasting more than a week. Just curious, did you take them the same day as pharmaceutical drugs? What was your ginseng dosage and extract potency?
      Q. I feel much better now after two weeks and I have medical help as it triggered of a panic attack and an overwhelming sense of anxiety. I took Ginseng just out of interest and I did not use anything else. The dosage was 200 mg and I also contacted Korean company that produced it.

Mechanisms of action, how it works
The roots of Chinese and American ginseng contain several saponins named ginsenosides that are believed to contribute to their properties. Saponins are interesting natural compounds found in many plants, herbs, roots, and beans. They are used in traditional Chinese medicine to improve stamina and combat fatigue and stress. Saponins have potential in the prevention and treatment of diseases of the heart and circulatory system. For instance, they inhibit the formation of lipid peroxides (fat oxidation) in cardiac muscle and in the liver. Saponins also influence the function of enzymes; decrease blood coagulation, cholesterol, and sugar levels in the blood; and stimulate the immune system. Some saponins may even have anti-tumor properties. Recent studies in laboratory animals have shown that both the Asian and American forms of ginseng enhance libido and copulatory performance. These effects of ginseng may not be due to changes in hormone secretion, but to the direct effects of ginseng, or its ginsenoside components, on the central nervous system and gonadal tissues. There is good evidence that ginsenosides can facilitate penile erection by directly inducing the vasodilatation and relaxation of penile corpus cavernosa. Moreover, the effects of ginseng on the corpus cavernosa appear to be mediated by the release of nitric oxide from endothelial cells and from nerves that surround the vessels. Treatment with American ginseng also affects the central nervous system and has been shown to significantly alter the activity of hypothalamic catecholamines, such as dopamine and norephinephrine, involved in the facilitation of copulatory behavior and hormone secretion. According to recent findings, that ginseng treatment decreases prolactin secretion, which also suggests a direct effect of ginseng at the level of the pituitary gland. High levels of prolactin inhibit libido. Studies sometimes have provided contradictory results, 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.

Review
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. Ginseng may help in erectile dysfunction but there are other herbs that are more effective..

Experience
The sexual effects from ginseng are subtle but definitely present. We have tried Asian ginseng on numerous occasions. Most of my trials have been with ginseng root powder at a dosage ranging from 500 to 1,000 mg. We notice an enhancement in alertness, motivation, focus, and mood, along with a mild sexual stimulation. The effects seem to improve on subsequent days of use. I find high doses to cause anxiety and interfere with sleep.