Panax Ginseng

What ginseng is

What is meant here is Panax ginseng, also called Korean or Asian ginseng. The root is used. Red and white ginseng are the same plant; the names stand for two types of processing. American ginseng, Panax quinquefolius, is a different species, and some studies and reviews lump the two together.

The ginsenosides, a group of saponins, are considered the most important constituents. Standardized extracts are adjusted to their content; the EU monograph lists, for example, a dry extract with 4 percent ginsenosides. Because ginseng is sold in so many forms, studies are often difficult to compare.

How it is supposed to work

Many effects of ginsenosides have been described in the laboratory. In humans, one point in particular has been measured: in a British crossover study, single doses of 200 and 400 mg of a standardized extract lowered blood sugar in 30 healthy young adults at all three measurement points after intake. The authors suspect that this effect is related to better concentration under sustained mental load.

Neuroprotective effects, by contrast, have so far been described mainly from cell culture and animal experiments.

Energy and fatigue

This is the use ginseng traditionally stands for, and the data here are friendlier than is often claimed. In a Korean study with 90 people with chronic fatigue without an identifiable cause, participants received 1 or 2 g of an extract or placebo for 4 weeks. The total score on the fatigue scale did not fall significantly more than with placebo, but mental fatigue did, and with 2 g so did fatigue on the visual analog scale. A 2018 systematic review of 10 studies with Asian and American ginseng found modest evidence against fatigue in people with chronic illness, and a 2023 review of 19 studies with 2,413 participants cited by the NCCIH saw a small benefit for ginseng alone in general fatigue.

There are also indications in healthy people, albeit from small short-term studies. In the crossover study mentioned, a single dose of 200 mg improved mental arithmetic and reduced subjective mental fatigue during a demanding test series.

User reports and tradition

How people actually use ginseng is shown by a 2025 Chinese survey of 5,041 people at 15 medical facilities. 72.78 percent said they used ginseng, people without a chronic illness mainly to strengthen their defenses. 68.14 percent were satisfied overall, among the chronically ill only 41.39 percent, and 52.30 percent reported side effects. These are self-reports without a control group, and many respondents used American ginseng.

One idea from Traditional Chinese Medicine is that high-dose red ginseng generates “heat”. A randomized study with 180 participants tested this in 2019: after 4 weeks with 1.8 or 3.6 g per day there was no increase in heat symptoms compared with placebo, but there was less fatigue.

What the studies show

Zeng 2024, cognition across all groups

Systematic review and meta-analysis of 15 randomized trials with 671 participants, including healthy people and people with cognitive impairment, schizophrenia and Alzheimer’s disease. Ginseng improved memory with a standardized mean difference of 0.19, high doses with 0.33. The authors found no effect on overall cognitive performance, attention and executive functions.

Reay 2005, single dose under sustained load

Double-blind, placebo-controlled crossover study with 30 healthy young adults who received 200 mg, 400 mg or placebo and then completed a ten-minute test battery six times in a row. Both doses lowered blood sugar significantly. 200 mg improved serial sevens subtraction and reduced subjective mental fatigue almost throughout.

Lee 2021, Cochrane on erectile dysfunction

Nine studies with 587 men with mild to moderate erectile dysfunction, all against placebo, follow-up up to 12 weeks. On the erectile function questionnaire IIEF-15, ginseng improved the score by 3.52 points, with a minimal clinically important difference of 4; the authors regard this as trivial. The self-reported ability to have intercourse increased with a risk ratio of 2.55. The evidence is predominantly low, and comparisons with PDE-5 inhibitors are lacking.

Shishtar 2014, blood sugar

Meta-analysis of 16 randomized trials of at least 30 days in people with and without diabetes. Ginseng lowered fasting blood sugar by 0.31 mmol/l, with no significant effect on HbA1c, fasting insulin or insulin resistance. 67 percent of the studies ran for less than 12 weeks.

Where the data stop

The biggest problem is quality. A 2023 umbrella review found a total of 19 meta-analyses, of which 5 were methodologically weak and 14 critically weak. The NCCIH points out that most studies had fewer than 200 participants and ran for less than 3 months. The 2010 Cochrane review on cognition found no convincing evidence of enhanced performance in healthy people, and in people with dementia the small improvements do not reach the threshold of clinical relevance according to a 2026 meta-analysis. For athletic performance, the majority of studies show no benefit. That the effect builds up over weeks has not been demonstrated: in a study with 8 days of intake, repeated dosing brought no additional benefit over the first dose. For blood pressure, a meta-analysis of 17 studies showed no effect, a newer one of 45 studies a reduction in systolic pressure of 2.57 mmHg with high heterogeneity. For the immune system there are only very preliminary data suggesting a lower risk of flu, but not a milder or shorter illness.

Status, approval and legal

In the EU there is a 2024 EMA monograph for Panax ginseng as a traditional herbal medicinal product for fatigue and weakness. The classification is based on long-standing use, not on clinical proof of efficacy. The monograph limits use to 3 months and specifies 40 to 200 mg daily for the extract standardized to 4 percent ginsenosides; use under 18 years of age is not recommended. Ginseng is also on the market as a food supplement. There are no authorized health claims, because the assessment of botanical claims has been suspended for years.

Safety

In the short term, ginseng is well studied. According to the NCCIH, oral intake for up to 6 months in usual amounts appears safe for most people; the most common side effect is sleep disturbance. A systematic review of side effects found a similar frequency to placebo in clinical trials with single-ingredient preparations, most commonly headache, sleep disturbances and gastrointestinal complaints; more serious events come from individual case reports and combination preparations. Caution is warranted with warfarin: one case report described weakened anticoagulation, and in 24 healthy people Asian ginseng increased the clearance of S-warfarin by a factor of 1.14, without a direct effect on clotting. Ginseng can lower blood sugar; with diabetes medication this belongs in the hands of a physician. LiverTox considers liver damage from ginseng alone unlikely, but describes cases with concomitantly taken medicines such as imatinib. In pregnancy and breastfeeding, the EMA advises against use for lack of data.

Sources

• EMA/HMPC, EU herbal monograph Panax ginseng, radix, 2024
• NCCIH, Asian Ginseng, 2025
• Zeng et al., Phytother Res 2024
• Kim et al., Complement Med Res 2025
• Geng et al., Cochrane Database Syst Rev 2010
• Lee et al., Cochrane Database Syst Rev 2021
• Reay et al., J Psychopharmacol 2005
• Kim et al., PLoS One 2013
• Shishtar et al., PLoS One 2014
• Coon and Ernst, Drug Saf 2002