Ginseng: Immediate Effects, Action Timeline and Treatment Duration, According to Studies

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Red Ginseng HRG80

A Panax ginseng root cultivated hydroponically, in indoor soil-free culture, without pesticides or chemical fertilizers, standardized for rare ginsenosides (Rg3, Rg5, Rk1) and verified in each batch. Two vegetable capsules per day provide 200 mg of HRG80 root extract, with a large glass of water, all at once or spaced throughout the day.

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Researchers distinguish two types of trials. Acute trials give a single dose and measure its effects in the hours that follow, often at 1, 2.5, 4, and 6 hours, according to a crossover design: each volunteer receives, approximately a week apart, the placebo and the different doses. Course trials compare over weeks a group taking ginseng daily to a placebo group.

Second distinction: the word ginseng covers several plants and preparations. Panax ginseng, or Asian ginseng, is consumed white, simply dried, or red, steamed then dried. This cooking modifies its ginsenosides, the compounds considered its active principles: some of the ginsenosides Rb1, Rb2, and Rc becomes, for example, Rg3. Panax quinquefolius, or American ginseng, has a different ginsenoside profile. Standardized extracts are added to these: G115 for Panax ginseng, Cereboost for American ginseng, HRG80 for a red ginseng grown hydroponically.

The authors of a trial on American ginseng conclude that its effects on the brain depend closely on its ginsenoside profile: a result obtained with one preparation does not transfer to another. Our comparison red or white ginseng details these differences, and our article on ginseng benefits covers the studied effects.

Most of the data comes from crossover trials conducted by the same university team with the standardized extract G115. In the first, 20 young adults received 200, 400, or 600 mg of G115 or placebo, with computerized tests at 1, 2.5, 4, and 6 hours. At 400 mg, "memory quality" improved at each measurement, from the first hour onward. At 200 and 600 mg, attention speed decreased at the last measurements, and perceived alertness was lower 6 hours after 200 and 400 mg.

Subsequent trials point in the same direction: attention and memory tasks faster with 200 mg of G115 in 28 young adults, improved mental calculation and reduced mental fatigue at the end of long tasks in 27 others, as with a drink of 25 g glucose. After 8 days of daily intake, the effects from day one were neither amplified nor diminished: 400 mg improved mental calculation on days 1 and 8, perceived calm on day one; 200 mg conversely slowed down calculation responses.

With American ginseng, it is primarily working memory that improves: 100 to 400 mg of Cereboost, an extract standardized to 10.65% ginsenosides, improved it 1 to 6 hours after intake in 32 young adults, without affecting blood sugar, and 200 mg at 3 hours in 52 adults aged 40 to 60.

These results remain limited: small trials, variable effects depending on dose, and the Cochrane review finds no convincing evidence of an effect of Panax ginseng on cognition in healthy individuals. For other strategies against mental fatigue, see our article mental fatigue: what to do.

This is an acute effect measurable from the first hour, variable depending on the ginseng. In healthy fasting volunteers, 200 and 400 mg of G115 lowered blood glucose at each measurement following intake, and 200 mg lowered it from the first hour in a second trial, when ginseng was taken without sugar.

With American ginseng, everything depends on timing. In 10 non-diabetic adults, 3 g taken 40 minutes before 25 g of glucose reduced the glycemic response by 18%, but not when taken at the same time. In 9 people with type 2 diabetes, the reduction reached 19% before and 22% during. The authors advise non-diabetic individuals to take this ginseng with meals to avoid inadvertent hypoglycemia.

Not all ginsengs are equal: in 12 healthy adults, eight ginsengs at 3 g had opposite effects, Asian ginseng increasing blood glucose after a sugary drink, while American and Vietnamese ginseng tended to lower it. In a course of treatment, a meta-analysis of 16 trials lasting at least 30 days found a modest decrease in fasting blood glucose of 0.31 mmol/L, with no overall effect on glycated hemoglobin.

Practical consequence: with antidiabetic treatment, ginseng may expose individuals to excessive blood glucose reduction. This is why our Red Ginseng HRG80 and our Organic red ginseng powder are not recommended for people on antidiabetic treatment. Our article on elevated blood glucose presents the studied options.

For physical exercise, the data are less favorable. A systematic review of 14 trials on red ginseng, three of which tested a single dose before exercise, found no improvement in aerobic capacity, nor, for most measurements, anaerobic power, with trials of low methodological quality. In treatment courses lasting 4 to 8 weeks, a meta-analysis of 8 trials and 212 participants found no effect on physical performance, with an effect size of −0.01.

Ginseng is therefore not a quick fix to take just before a workout. If fatigue sets in over the course of training, our guide fatigue or overtraining helps you find the cause.

HRG80 is obtained from Panax ginseng roots cultivated hydroponically, steam-cooked to produce a red ginseng, then reduced to powder; according to the pilot trial authors, this cooking converts some of the major ginsenosides into so-called rare ginsenosides, such as Rg3 or Rk1. We identified three human studies with HRG80 in PubMed.

This is a pilot trial, with two weeks per treatment and without correction for multiple comparisons, whose first author works for the HRG80 producer; the authors themselves call for larger, longer trials. On memory, the effect appeared only on day 12, as with the commercial preparation. The dose was two capsules of 209 mg of HRG80 root powder, or 418 mg per day; our Red Ginseng HRG80 provides 200 mg of HRG80 root extract per day, in two capsules, or approximately twice less than in this trial, which did not test this dose (the open trial described below: 100 to 400 mg per day). For reference, one HRG80 capsule from the trial contained 31.8 mg of ginsenosides for 209 mg of powder, the commercial preparation 9.8 mg for 382 mg.

An electroencephalography study in 30 people aged 60 to 75 compared HRG80, a white ginseng powder, and placebo, two capsules each morning for 4 weeks. Recorded 2 hours after intake, the brain's electrical activity deviated slightly more from placebo with HRG80 from day one (differences described, not tested), in the frontal and temporal regions during an attention test, and after 4 weeks, both ginsengs produced significant changes, judged comparable by the authors. This is an indirect marker, not performance scores.

An open trial in 188 people with chronic fatigue syndrome or fibromyalgia reports 60.1% of participants reporting improvement after one month of HRG80, at 100 to 400 mg per day; the authors emphasize the absence of placebo, subjective criteria, and approximately one quarter of enrolled participants lost to follow-up.

Finally, a larger randomized trial involved a red Panax ginseng root powder cultivated hydroponically and rich in rare ginsenosides, whose text does not specify the brand name. In 149 moderately stressed adults, 200 mg per day for 3 weeks lowered the perceived stress score by 4.3 points, compared to 2.7 under placebo, and reduced negative emotions, effects that the authors consider moderate. For other studied effects of red ginseng, see our article red ginseng: benefits.

For fatigue, a meta-analysis of 4 trials and 429 participants, combining Asian and American ginseng, finds an effect size of 0.34, between small and medium, significant only beyond 6 weeks of use (0.39) and from 1 g per day (0.40). The authors nonetheless judge the evidence insufficient, as 271 of the 429 participants came from a single trial. These thresholds apply to the preparations studied, with different concentrations, which do not compare gram for gram.

Shorter trials are mixed: in 90 people suffering from unexplained chronic fatigue, 4 weeks of Panax ginseng extract, at 1 or 2 g per day, did not reduce overall fatigue score compared to placebo, but improved its mental component, and the visual fatigue scale with 2 g. A more recent meta-analysis of 19 trials, including formulas combining ginseng with other plants, finds no overall effect; small but significant effects with formulas (0.39), in chronic fatigue (0.30), and without identified disease (0.48). Our article ginseng and fatigue goes into detail on these trials.

For erectile function, the Cochrane review brings together 9 trials and 587 men suffering from mild to moderate disorders, followed for no more than 12 weeks: effect judged minimal on the erectile function score, 3.52 points out of 30, below the clinical relevance threshold of 4 points, but ability to have intercourse, reported by men, 2.55 times more frequent, with a weak level of evidence. Our article ginseng, libido and erectile function details these trials.

For immune defenses, a review of 5 trials and 747 participants concerns only American ginseng, taken preventively for 8 to 16 weeks: colds were shortened by 6.2 days in two trials, with no significant decrease in the number of people with colds. Our article immunity: what really works presents other options.

The most abundant ginsenosides in ginseng, such as Rb1, are poorly absorbed. Colon bacteria transform them into simpler metabolites, the most studied of which is compound K. In 10 men who took 9 g of Korean red ginseng extract, compound K was detected in the blood between 4 and 9 hours after intake (first sample at 4 hours), and it peaked on average at 12.2 hours; its half-life was approximately 8 hours.

These individual differences are the rule: the ability to convert ginsenosides varies with diet, health status and stress, according to the authors of another Korean study. In 13 men, they showed that a red ginseng extract treated with enzymes, enriched in Rg3, Rk1, Rg5 and compound K, was better absorbed than the standard extract, with a compound K peak at an average of 4.8 hours, versus 8.2 hours.

This enriched extract owed its rare ginsenosides to enzymes, those of HRG80 come from steam cooking: our HRG80 Red Ginseng is standardized for Rg3, Rg5 and Rk1 and standardized for each batch. We have not identified any studies measuring the absorption rate of HRG80 itself in humans: its trials measured effects from the first day, without describing its blood kinetics.

No identified trial compares morning and evening intake, but recent trials gave ginseng in the morning: at 10 a.m. in the pilot trial on HRG80, every morning in seniors and in the 3-week stress trial. Sleep disturbances are among the most frequently reported adverse effects, and 7 participants in the open trial found HRG80 too stimulating: preferably take it in the morning or late morning, earlier if falling asleep becomes difficult.

With or without meals? The pharmacokinetic studies cited here were conducted on an empty stomach, but breakfast has an argument: on an empty stomach, G115 lowered blood sugar within an hour, and the authors of the American ginseng trial advise non-diabetics to take it with meals. This is practical advice, not a result on efficacy.

Both formats work well: two capsules of HRG80 Red Ginseng with a large glass of water, together in the morning or spaced between morning and noon, or a teaspoon of organic red ginseng powder, approximately 2 g, in a hot morning beverage, added at the end of preparation. For variety, our recipe forginger lemon infusion can serve as a base.

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Organic Red Ginseng Powder

100% whole root red ginseng (Panax ginseng C.A. Meyer) from organic farming, micronized, with no additives or fillers. One teaspoon per day, approximately 2 g, in hot water, herbal tea, smoothie or dish, added at the end of preparation.

See Red Ginseng Powder

Most trial courses last 4 to 16 weeks. One of the longest, in 200 patients with chronic obstructive pulmonary disease, gave 200 mg of G115 twice daily for 24 weeks: without reducing exacerbations, it was well tolerated, with as many adverse effects as placebo. Beyond that, the effects of prolonged intake remain unknown, according to the authors of the 3-week stress trial.

Should you take breaks? The data are limited: after 8 days of G115, acute effects were not diminished; in a small 8-week trial in 30 adults, 200 mg per day of Panax ginseng improved social functioning and overall mental health score at 4 weeks, but not at 8 weeks, and ginseng participants guessed more often that they were receiving the active product (58% versus 17%). The break therefore remains a reasonable precaution, not a proven rule.

In acute trials, ginseng does not have the profile of a stimulant: 400 mg of G115 and 100 mg of American ginseng increased perceived calm, and perceived alertness was lower 6 hours after 200 or 400 mg of G115. On a pharmacokinetic level, the combination with coffee showed no notable interaction: in 15 healthy men, 15 days of red ginseng extract only weakly modified the elimination of a cocktail of marker drugs, caffeine included, a risk of interaction deemed minimal by the authors.

Energy drinks that highlight ginseng muddy the waters: in 20 volunteers, a beverage combining 37.5 g of glucose, 75 mg of caffeine and ginseng at a simple aromatic dose improved memory and attention speed; the authors see a synergy between glucose and caffeine.

In practice, if you are sensitive to caffeine or if your sleep is fragile, keep coffee and ginseng for the morning. In the pilot trial on HRG80, coffee was moreover limited to one cup in the morning, as a methodological precaution. Our article on caffeine before exercise details its doses, timing, and effect on sleep.

In a systematic review of safety data, the frequency of adverse effects under ginseng alone was close to that of placebo; the most frequent were headaches, sleep disturbances and digestive disorders, generally mild and transient. In a 4-week trial at 1 or 2 g per day of Panax ginseng extract, digestive discomfort, hot flushes, insomnia and constipation appeared also under placebo, and the Cochrane review on erectile function finds no significant difference in adverse effects with placebo (weak evidence).

Trials on HRG80 describe effects of the same order. In the open trial, over one month, 7 participants found the product too stimulating, 3 had diarrhea, 3 worsening of their headaches, and one person saw their blood sugar drop to 61 mg/dL. In the pilot trial, 3 of the 50 participants reported a bothersome event: diarrhea with the commercial preparation, abdominal distension and fatigue under placebo or HRG80.

Interactions deserve more attention. In 20 healthy volunteers receiving warfarin, two weeks of American ginseng reduced the anticoagulant effect (maximum INR lowered by 0.19 compared to placebo). In 12 volunteers, 28 days of Panax ginseng at 500 mg twice daily reduced midazolam exposure by approximately one third, a sign of CYP3A enzyme activation, which eliminates many drugs. Conversely, 15 days of red ginseng extract did not cause notable interaction in the drug cocktail study. The safety review also cites possible interactions with phenelzine, an MAOI antidepressant, and with alcohol.

Our complete ginseng guide details all precautions, and our file on chronic fatigue presents other plants and nutrients studied when energy is lacking.

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