Ginsenosides

Ginsenosides: A Comprehensive Reference

1. Identity: Botanical Origin, Chemical Classification, and Natural Sources

Botanical Source and Nomenclature

Ginsenosides are a special group of triterpenoid saponins that can be classified into two groups by the skeleton of their aglycones, namely dammarane- and oleanane-type. They are found nearly exclusively in Panax species (ginseng). The genus name Panax derives from the Greek word meaning "all-healing," reflecting the plant's long-standing reputation in traditional medicine. The primary commercial species are Panax ginseng C.A. Meyer (Asian/Korean ginseng), Panax quinquefolius L. (American ginseng), and Panax notoginseng (notoginseng/tienchi ginseng), all members of the family Araliaceae.

Up to now, more than 150 naturally occurring ginsenosides have been isolated from roots, leaves/stems, fruits, and/or flower heads of ginseng. Traditionally, ginseng refers to the root, and the other parts of ginseng, such as the leaves and berries, are rarely used.

Chemical Structure

Ginsenosides are triterpenoid saponins with a four-ring skeleton structure and are unique to ginseng species belonging to the genus Panax. Ginsenosides are triterpene saponins. Most ginsenosides are composed of a dammarane skeleton (17 carbons in a four-ring structure) with various sugar moieties (e.g., glucose, rhamnose, xylose, and arabinose) attached to the C-3 and C-20 positions.

Ginsenosides are named as 'Rx', where the 'R' stands for the root and the 'x' describes the chromatographic polarity in an alphabetical order; for example, Ra is the least polar compound and Rb is more polar than Ra.

Classification

Ginsenosides are classified into three groups based on their aglycone structure: protopanaxadiol (PPD)-type ginsenosides, protopanaxatriol (PPT)-type ginsenosides, and oleanolic acid-type ginsenosides. These three groups are further classified based on the position and number of sugar moieties attached by a glycosidic bond at C-3, C-6, and C-20 positions of the rings in the chemical structure (aglycone). The oleanolic acid-type ginsenoside has a pentacyclic backbone and ginsenoside Ro is the only saponin having oleanolic acid as its aglycone.

To date, more than 40 ginsenosides have been isolated, and most of these are PPD-type ginsenosides. PPD-type ginsenosides include Rb1, Rb2, Rb3, Rc, Rd, gypenoside XVII, compound O, compound Mc1, F2, compound Y, compound Mc, Rg3, Rh2, and C-K. PPT-type ginsenosides include Re, Rg1, Rf, Rg2, Rh1, etc.

The main ginsenosides include the PPD-type ginsenoside Rb1, Rb2, Rc, Rd, and PPT-type ginsenoside Re and Rg1 in ginseng, which account for more than 90% of the total ginsenoside content.

The ginsenosides identified to date are classified as the protopanaxatriol type (PPT), protopanaxadiol type (PPD), oleanolic acid type (OA), ocotillol type (OT), C17 side-chain varied (C17SCV), and miscellaneous subtypes according to their known structures. The oleanane group consists of OA and OT types: the OA type consists of a pentacyclic structure with an aglycone oleanolic acid such as ginsenoside Ro; the OT has an epoxy ring at C–20, and includes majonoside R2 and the pseudoginsenoside F11.

Common Preparations and Commercial Forms

Fresh ginseng refers to immediate harvest without any additional processing. Because of problems during storage or circulation, in most cases, fresh ginseng is turned into white or red ginseng. White ginseng refers to dried ginseng, while red ginseng is the transformed ginseng created by traditional processing with successive steaming and drying.

The steaming process used to produce red ginseng significantly alters the ginsenoside profile, converting major ginsenosides into less abundant but biologically active forms such as Rg3, Rh1, and Rh2. The ginsenoside content of red ginseng has been reported as Rg1: 3.3 mg/g, Re: 2.0 mg/g, Rb1: 5.8 mg/g, Rc: 1.7 mg/g, Rb2: 2.3 mg/g, and Rd: 0.4 mg/g. The red ginseng extract is prepared through a water extraction (90°C for 14–16 hours) and concentration process (until its final concentration is 70–73 Brix at 50–60°C).

Ginsenosides are commercially available in a range of forms, including standardized root powders and capsules, standardized liquid and dry extracts, isolated individual ginsenosides (e.g., Rg3, Rh2, compound K), and fermented or enzymatically processed preparations designed to enhance bioavailability.

2. Traditional and Historical Use

Chinese and East Asian Traditions

The medicinal history of ginseng can be traced back over approximately 2,000 years to one of the first descriptions in ancient Oriental medical literature. In China, ginseng preparations have been used for thousands of years in traditional medicine. The English name 'ginseng' is derived from the Chinese word meaning man-shaped root. Owing to this shape, ginseng is considered sacred in oriental medicine.

Among the 113 prescriptions described in the Shang-Han Lun, which was written by Zhong Jing Zhang (150–219 AD), 21 prescriptions contained ginseng. The Shang-Han Lun covers specific symptoms of disorders and their corresponding treatments and is designated as one of the four fundamental texts of traditional Chinese medicine. Among the 3,944 prescriptions in the Donguibogam, written by Jun Heo, 653 prescriptions contained ginseng as an ingredient.

Several traditional prescriptions were prepared from ginseng, which was used for its restorative, tonic, nootropic, and anti-aging properties. Panax ginseng Meyer has been widely used as a tonic in traditional Korean, Chinese, and Japanese herbal medicines and in Western herbal preparations for thousands of years.

In Traditional Chinese Medicine (TCM), ginseng is known to have a warming effect on the body and is used to tonify Qi (vital energy). Its slightly bitter taste is believed to help clear dampness and stagnation from the body.

Korean Tradition and Red Ginseng

It has been reported that Korean Red Ginseng has been manufactured for 1,123 years as described in the GoRyeoDoGyeong record. Korean traditional medicine used ginseng primarily as an adaptogenic tonic, prescribed to strengthen constitution, improve stamina, and support recovery from illness. Ginseng has long been used as a dietary supplement and regulator to relieve fatigue in Eastern countries, especially in China, Korea, and Japan.

American Ginseng

Demand for ginseng roots in the 18th century intensified the wild harvest of the main species Panax ginseng C.A. Mey. (Korean ginseng) and nearly extirpated it from the wild, but also fuelled a rapid expansion in wild-harvesting of Panax quinquefolius L. (American ginseng) that in turn destroyed wild populations in North America. American ginseng was used by several Native American peoples and later adopted into colonial herbal practice. In TCM, American ginseng (xi yang shen) was considered to have a cooling nature, in contrast to the warming nature attributed to Asian ginseng.

Intended Traditional Purposes

Across all traditions in which it was employed, ginseng root was prepared and administered as decoctions (boiled water extracts), tinctures, powders, and as an ingredient in complex multi-herb formulations. Traditional purposes attributed to ginseng and, by extension, its ginsenoside constituents (though the constituent-level attribution is a modern construct) included: strengthening vital energy (Qi), tonifying the spleen and lung, calming the mind, improving memory and mental clarity, enhancing physical endurance, and supporting recovery from weakness, illness, and aging. Ginseng has always been regarded as the "king of herbs" in Chinese traditional medicine, as it enhances fitness and tranquilizes the mind.

3. Key Constituents and Active Compounds

The Major Individual Ginsenosides

Based on the structural characteristics of steroidal saponins, ginsenosides are mainly divided into protopanaxadiol-type saponins (PDS, mainly including Rb1, Rb2, Rd, Rc, Rh2, CK, and PPD) and protopanaxatriol-type saponins (PTS, mainly including Re, R1, Rg1, Rh1, Rf, and PPT). Key ginsenosides of particular research interest include:

• Ginsenoside Rg1 (PPT-type): Ginsenoside Rg1 is the most abundant and active ginsenoside and has a structure similar to that of steroid hormones. It is among the most extensively studied individual ginsenosides for neuroprotection and cognitive effects.
• Ginsenoside Rb1 (PPD-type): Ginsenoside Rb1 is one of the most important active ingredients in Panax ginseng and Panax notoginseng. In the last two decades, more attention has focused on ginsenoside Rb1 as an antioxidative, anti-apoptotic, and anti-inflammatory agent that can protect the nervous system.
• Ginsenoside Rg3 (PPD-type): A minor ginsenoside in fresh root that accumulates during steaming to produce red ginseng. GS-Rg3 is one of the most studied ginsenosides and also one of the effective anticancer herbal ingredients.
• Ginsenoside Rh2 (PPD-type): Occurs in very small amounts in fresh ginseng but is enriched in red ginseng. It has been studied for anticancer and immunomodulatory effects.
• Ginsenoside Re (PPT-type): Re is also known to eliminate virus, enhance the immune response, improve osteoporosis, improve skin barrier function, enhance intracellular anti-oxidant actions, regulate cholesterol metabolism, alleviate allergic responses, and increase sperm motility, among other activities.
• Compound K (20-O-β-(D-glucopyranosyl)-20(S)-protopanaxadiol; CK): Although the structure of CK was unraveled by early 1996, it did not attract much attention until the specific metabolizing pathways for converting ginsenosides to CK, carried out by the intestinal flora, were determined. Moreover, compared to the ginsenosides, CK is better absorbed in the gut. Often, the most active component in ginseng is considered to be CK, with just one glucopyranosyl group.

Biotransformation and Metabolism

Ginsenosides can be metabolized in the stomach (acid hydrolysis) and in the gastrointestinal tract (bacterial hydrolysis) or transformed to other ginsenosides by drying and steaming processes. The metabolization of intact ginsenosides plays an important role in their biological effects. Large, polar ginsenosides (e.g., Rb1, Rc, Rd) are poorly absorbed in their intact form and are extensively converted by intestinal microbiota into compound K (CK) before systemic absorption. The bioavailability rate of ginsenosides without conversion or modification indicates limited intestinal absorption. According to research, some microorganisms and gut bacteria or soil fungi around ginseng roots hydrolyze ginsenosides to produce CK. It is essential to research the metabolic processes that control intestinal microbiota since it plays a crucial role in the biological transformation and therapeutic effects of CK.

The structural differences between PDS and PTS result in differences in pharmacological activities. As a general principle, PPD-type ginsenosides tend to display sedative, anti-proliferative, and hypoglycemic properties, while PPT-type ginsenosides tend to demonstrate stimulatory, neuroprotective, and immunomodulatory effects, although there is considerable overlap and individual ginsenoside behaviour varies considerably.

4. Mechanisms of Action

Antioxidant Mechanisms

Many studies have reported that various ginsenoside monomers (such as ginsenosides Rg1, Rb1, and Rh3) can exert antioxidant effects by activating the Keap1/Nrf2/ARE signaling pathway. Ginsenoside Rg1 can also inhibit liver inflammatory reactions and reduce the expression of TNF-α, interleukin-1 beta (IL-1β), IL-6, and COX-2, and its potential mechanism of action may be related to the activation of the Nrf2 signaling pathway. Ginsenoside CK has neuroprotective and antioxidant effects via activation of the Keap1/Nrf2/HO-1 signaling pathway.

Anti-inflammatory Mechanisms

Ginsenosides exert effective neuroprotective effects on neurological conditions, including stroke, Alzheimer's disease, Parkinson's disease, and brain/spinal cord injuries through a variety of molecular mechanisms, including anti-inflammatory, antioxidant, and anti-apoptotic. Among them, some signaling pathways play important roles in related processes, such as PI3K/Akt, TLR4/NF-κB, ROS/TXNIP/NLRP3, HO-1/Nrf2, Wnt/β-catenin, and Ca²⁺ pathways. Ginsenoside Rh2 inhibited the expression of COX-2, TNF-α, and IL-1β, and promoted the anti-inflammatory cytokine IL-10, depending on the AP-1 and protein kinase A (PKA) pathway.

Neuroprotective Mechanisms

The neuroprotective mechanisms of ginsenosides include antioxidant effect, antiapoptosis effect, estrogen-like effect, restraining the influence of nitric oxide and nitric oxide synthase, and improving mitochondrial dysfunction. It is believed that Rg1 could cross the blood–brain barrier and exert potential neuroprotective effects. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) play a significant role in Alzheimer's disease. The inhibition of AChE and BChE provides additional benefits in AD treatment. Ginsenosides Rb1, Rb2, Rc, Re, Rg1, and Rg3 have significant inhibitory effects against AChE and BChE.

Anticancer Mechanisms

Ginsenosides exert their anticancer effects by modulation of diverse signaling pathways, including regulation of cell proliferation mediators (CDKs and cyclins), growth factors (c-myc, EGFR, and vascular endothelial growth factor), tumor suppressors (p53 and p21), oncogenes (MDM2), cell death mediators (Bcl-2, Bcl-xL, XIAP, caspases, and death receptors), inflammatory response molecules (NF-κB and COX-2), and protein kinases (JNK, Akt, and AMP-activated protein kinase).

The anticancer activities of ginsenosides and their metabolites have complicated antitumor mechanisms; they achieve antitumor effects mainly through inhibiting tumor cell proliferation, invasion, and metastasis; inducing tumor cell apoptosis, autophagy, and cell cycle arrest; and enhancing cell immune regulation.

Antidiabetic Mechanisms

Recent studies have revealed that ginsenosides play roles in the treatment of diabetes and its complications dominantly through improving insulin resistance, regulating glucolipid homeostasis, preventing oxidative stress, and inflammatory responses. Ginsenosides may improve blood glucose through the regulation of glucose absorption, intervention in glucose transport and/or glucose disposal, and the alteration of insulin secretion and binding. Ginsenosides control glucolipid metabolism mainly through regulation of AMPK and its downstream substrates including PEPCK and G6Pase, two key enzymes of gluconeogenesis, as well as ACC and HMGCR, rate-limiting enzymes in the synthesis of fatty acids and cholesterol, respectively.

Cardiovascular Mechanisms

Numerous studies have indicated that ginsenosides have potential cardiovascular benefits, including antioxidative, anti-inflammatory, and anti-apoptotic effects, and have also been found to regulate mitochondria. Several preclinical studies have indicated that ginseng and the major bioactive ingredient (ginsenosides) can modulate several cardiovascular diseases through diverse mechanisms.

Steroid Hormone-like Activity

Ginsenosides may act as ecdysteroids — the insect molting and metamorphosis hormones — due to the structural similarities between the two groups of chemicals. The ecdysteroids have a steroid backbone with a C-20 sugar side-chain and a C-3 hydroxyl group, resembling the structure of most of the PPT-type ginsenosides such as Rg1 and several metabolites of PPDs such as compound Y and compound K. This structural similarity to steroid hormones is considered relevant to observed effects on the glucocorticoid receptor and other nuclear receptors.

5. Scientific Evidence by Area of Health Effect

5.1 Cognitive Function and Neuroprotection

Current scientific studies demonstrate in vivo and in vitro beneficial effects in a wide range of pathological conditions such as cardiovascular disease, cancer, immune deficiency, and hepatotoxicity. Ginsenosides, as the active ingredients, have antioxidant, anti-inflammatory, anti-apoptotic, and immunostimulant properties, which raised speculations that these compounds could positively affect neurodegenerative disorders and delay neuronal aging. However, conclusive clinical data in humans are still missing.

Animal/Preclinical Evidence: A preclinical systematic review selected 32 studies including a total of 1,643 animals. According to various cognitive behavioral tests, the results of the meta-analyses showed that ginsenoside Rg1 significantly improved cognitive behavioral impairments in most Alzheimer's disease models (P < 0.05), but there were no significant effects in animals with neuronal degeneration induced by chronic stress or in SAMP8 transgenic mice.

Human/Clinical Evidence: A ginsenoside complex extracted from red ginseng was found to improve patients' cognitive function after at least 12 weeks of treatment. In another randomized controlled trial, 97 individuals were orally treated with Panax ginseng powder (which contains a total of 8.19% of ginsenosides) at a dose of 4.5 g/d or 9 g/d; the results demonstrated that ginsenoside supplementation can increase the Alzheimer's Disease Assessment Scale (ADAS) and Mini-Mental State Examination (MMSE) scores, revealing improvement of cognitive function. Furthermore, in a randomized, double-blind, placebo-controlled study, Korean red ginseng (KRG) administration at a dose of 1000 mg/day for 8 weeks was found to increase gray matter volume and composite cognitive scores in healthy individuals.

There have been numerous clinical trials and observational studies on ginseng supplementation. While some studies have shown benefit, others have shown a lack of benefit. In a 2020 systematic review of various randomized controlled trials in Alzheimer's patients testing various supplements, the overarching conclusion was that benefits of most dietary interventions on cognition in Alzheimer's patients remain inconclusive.

Evidence strength: Preclinical evidence for cognitive effects is substantial, but human clinical evidence is inconsistent and limited by small sample sizes, methodological heterogeneity, and variable ginsenoside standardization. Current evidence is considered preliminary.

5.2 Fatigue Reduction and Physical Performance

Ginsenosides, the most important ingredients of ginseng, have been documented with various pharmacological activities such as anti-fatigue, anti-oxidation, neuroprotection, anti-inflammation, and anti-diabetes. Ginsenoside Rg3 may improve exercise performance and increase fatigue resistance by enhancing deacetylase activity of silent information regulator of transcription 1 (SIRT1) and inhibiting the transcriptional activity of p53.

Human/Clinical Evidence: Out of 155 articles meeting initial criteria, 12 RCTs involving 630 participants (311 in the intervention group and 319 in the placebo group) were included in a meta-analysis. In the fixed-effect meta-analysis of four RCTs, there was a statistically significant efficacy of ginseng supplements on fatigue reduction (standardized mean difference, SMD = 0.34; 95% confidence interval [CI] = 0.16 to 0.52). Approximately 40 ginsenosides have been identified in P. ginseng with various pharmacological activities, such as effects on chemical stress, immune modulation in animal studies, antitumor activities, as well as glucose metabolism and enhancement of cognitive performance. However, those effects are not clinically established.

Evidence strength: Modest positive evidence exists for fatigue reduction from a meta-analysis of RCTs, but effect sizes are small and heterogeneity across studies is significant. Evidence for athletic performance enhancement remains inconsistent.

5.3 Diabetes and Blood Glucose Regulation

Accumulating evidence has shown that ginsenosides exert antidiabetic effects. In vivo and in vitro tests revealed the potential of ginsenoside Rg1, Rg3, Rg5, Rb1, Rb2, Rb3, compound K, Rk1, Re, ginseng total saponins, malonyl ginsenosides, Rd, Rh2, F2, protopanaxadiol (PPD), and protopanaxatriol (PPT)-type saponins to treat diabetes and its complications, including type 1 diabetes mellitus, type 2 diabetes mellitus, diabetic nephropathy, diabetic cognitive dysfunction, type 2 diabetes mellitus with fatty liver disease, diabetic cerebral infarction, diabetic cardiomyopathy, and diabetic erectile dysfunction.

Human/Clinical Evidence: An 8-week, randomized, double-blind, placebo-controlled clinical trial investigated the antidiabetic effects of hydrolyzed ginseng extract (HGE) in Korean participants. Participants with impaired fasting glucose (fasting plasma glucose ≥5.6 mM or <6.9 mM) who had not been diagnosed with any disease were recruited. The 23 participants were randomly divided into either the HGE (n=12, 960 mg/d) or placebo (n=11) group. After 8 weeks of HGE supplementation, fasting plasma glucose and postprandial glucose were significantly decreased in the HGE group compared to the placebo group.

A meta-analysis showed that ginseng reduced fasting blood glucose in patients. Ginseng also exerted antidiabetic effects as a supplemental treatment. The efficacy of ginseng extract or powder on blood glucose control has been well documented in experimental models and in healthy individuals. However, there are very few randomized controlled trials assessing the safety and efficacy of ginseng extract in patients with type 2 diabetes or people with impaired fasting glucose or impaired glucose tolerance. Besides, most studies conducted in human subjects only evaluated the effect of a single oral dose.

Five ginsenoside pharmaceutical preparations such as Tianqi capsule and Jinlida granule have been included for the clinical treatment of type 2 diabetes mellitus (T2DM) in China, indicating a promising future for ginseng in diabetes.

Evidence strength: Preclinical data are robust and mechanistically coherent. Human trial evidence is positive but limited by small sample sizes, short durations, and variability in preparations. Overall evidence is promising but not definitive for clinical therapeutic claims.

5.4 Cardiovascular System

Several preclinical studies have indicated that ginseng and the major bioactive ingredient (ginsenosides) can modulate several cardiovascular diseases through diverse mechanisms. However, there is paucity in the translation of such experiments into the clinical arena for cardiovascular ailments due to lack of conclusive specific pathways through which these activities are initiated and lack of larger, long-term, well-structured clinical trials.

There is a paucity in the translation of such experiments into the clinical arena for cardiovascular ailments due to lack of conclusive specific pathways through which these activities are initiated and lack of larger, long-term, well-structured clinical trials. One review elaborated on current pharmacological effects of ginseng and ginsenosides in the cardiovascular system and provides some insights into the safety, toxicity, and synergistic effects in human trials, concluding that before ginseng, ginsenosides, and their preparations could be utilized in the clinical treatment of cardiovascular diseases, there should be more preclinical studies in larger animals.

Evidence strength: Primarily preclinical. Mechanistic evidence from cell and animal studies is plentiful, but adequately powered clinical trials are lacking. Evidence is considered insufficient to support definitive cardiovascular therapeutic claims.

5.5 Anticancer Activity

Several pre-clinical and clinical studies have demonstrated the anticancer potential of Panax ginseng, a widely used traditional Chinese medicine. The anti-tumor efficacy of ginseng is attributed mainly to the presence of saponins, known as ginsenosides.

According to the evidence summarized, ginsenosides exhibit anticancer effects, including inducing cell cycle arrest and apoptosis, regulating autophagy, and reducing tumor invasiveness. Ginsenosides regulate the immune responses of myeloid and lymphoid cells within the tumor microenvironment (TME). Ginsenoside Rh2, Rg3, and CK enhance the infiltration of CD8+ T cells into transplantation tumors and increase granzyme production by inhibiting the expression of the key checkpoint PD-L1 on tumor cells. Ginsenosides trigger the infiltration and cytotoxicity of CD4+/CD8+ T lymphocytes and NK cells, promote the conversion of M2 macrophages to M1 macrophages, enhance TAM secretion, and reduce the number of immunosuppressive Tregs.

Human/Clinical Evidence (Rg3): 20(S)-ginsenoside Rg3 was produced as a new anticancer drug in China due to its antiangiogenic effect. Clinical studies show that Rg3, especially in combination with chemotherapy, can reduce chemotherapy side effects and improve life quality and survival rates of patients with non-small cell lung cancer, gastric cancer, and esophageal cancer. The mechanism might be correlated with antitumor angiogenesis and improving the immune function.

The further clinical application of ginsenosides in cancer treatment has been hampered by poor bioavailability and rapid plasma elimination.

Evidence strength: Extensive preclinical (in vitro and in vivo) evidence exists. Some adjuvant clinical use of Rg3 in China has been reported alongside chemotherapy, but large, independent randomized controlled trials confirming efficacy for specific cancer types remain limited. This area requires further rigorous clinical investigation.

5.6 Immune Modulation

Numerous studies have shown that ginsenosides have direct function in tumor cells through the induction of cancer cell apoptosis and the inhibition of cancer cell growth, and they enhance antitumor immunity through the activation of cytotoxic T lymphocytes and natural killer cells. Ginsenosides, as immunomodulatory drugs, may assist with other clinical antitumor antibodies such as anti-PD-1 antibodies by reducing the number of myeloid immunosuppressive cells and inhibiting their functions to improve the tumor microenvironment for enhancing antitumor activity of those antibodies.

Several rare ginsenosides represent promising immunomodulatory agents with distinct therapeutic applications. F1's unique immunostimulatory properties position it for cancer immunotherapy, while the complementary anti-inflammatory mechanisms of Rg5, Rk1, Rh1, and Rg2 offer opportunities for precision medicine in inflammatory diseases.

Evidence strength: Primarily preclinical. Immunomodulatory effects are well-characterized in cell-culture and animal studies. Translation to controlled human clinical studies with clearly defined immune endpoints remains limited.

5.7 Neuroprotection in Specific Neurological Conditions

Growing evidence shows that ginsenosides have neuroprotective effects in vivo and in vitro and have excellent potential as novel candidate agents for ischemic stroke. They can be used to treat ischemic stroke via reducing neurotoxicity, anti-oxidant effects, anti-inflammation, anti-apoptosis, anti-autophagy, regulating blood-brain barrier permeability, promoting angiogenesis and neurogenesis to alleviate nerve damage and promote nerve repair.

For Parkinson's disease and other neurodegenerative conditions, results from animal studies and neuronal cell culture experiments indicate that ginsenosides can counteract and attenuate factors promoting neuronal death, such as environmental toxins, excitotoxic action of glutamate, rises in intracellular calcium, excessive release of free radicals, and apoptotic events. Thus, neuroprotective actions of ginsenosides could come about as a valuable option to slow down neurodegenerative diseases.

Evidence strength: Strong preclinical evidence across multiple neurological disease models. Robust, adequately powered human RCTs are still largely absent for most specific indications.

6. Body Systems and Health Areas Associated with Ginsenosides

• Central Nervous System: Cognitive function, neuroprotection, Alzheimer's disease, Parkinson's disease, ischemic stroke, depression, epilepsy.
• Cardiovascular System: Antioxidant cardioprotection, anti-hypertensive effects, regulation of blood lipids, anti-atherosclerotic activity.
• Metabolic/Endocrine System: Blood glucose regulation, insulin sensitization, antidiabetic effects, lipid metabolism.
• Immune System: Immunostimulation, immunomodulation, regulation of tumor microenvironment, NK cell activation.
• Oncology: Anti-proliferative, pro-apoptotic, anti-angiogenic, and anti-metastatic effects as research and adjunctive clinical agents.
• Anti-aging/Antioxidant: Reduction of oxidative stress via Nrf2/ARE signaling, anti-fatigue effects.
• Musculoskeletal: Anti-fatigue, physical performance support.
• Skin: Compound K has been studied for skin barrier and inflammatory skin conditions.

The potential health effects of ginsenosides that have been discussed in research include anticarcinogenic, immunomodulatory, anti-inflammatory, antiallergic, antiatherosclerotic, antihypertensive, and antidiabetic effects, as well as antistress activity and effects on the central nervous system.

7. Dosage Forms and Reported Dosages

Ginseng Root Preparations

Studies have used a wide range of preparation types and doses, reflecting the absence of standardization across clinical trials. Specific dosages reported in human research include:

• A randomized controlled trial used Panax ginseng powder (containing 8.19% total ginsenosides) at a dose of 4.5 g/day or 9 g/day for cognitive outcomes.
• Korean red ginseng (KRG) was administered at 1,000 mg/day for 8 weeks in a randomized, double-blind, placebo-controlled study examining cognitive effects in healthy individuals.
• In an 8-week antidiabetic RCT, 23 participants received 960 mg/day of hydrolyzed ginseng extract (HGE).

Isolated Ginsenoside Compound K

In randomized, double-blind pharmacokinetic trials, 76 healthy Chinese subjects received one of seven single oral doses (25, 50, 100, 200, 400, 600, or 800 mg) of compound K or placebo under fasting conditions, and another 36 subjects received repeated oral doses (100, 200, or 400 mg) of compound K or placebo for up to 9 days. The range of time to maximum concentration (T_max) was 1.5–6.0 hours, with a linear increase in the exposure of CK over the dose range of 100–400 mg.

Bioavailability Considerations

In their hydrophilic chemical structure, ginsenosides' solubilities depend on the amount of sugar moieties, with a positive correlation. However, most ginsenosides with anticancer activity have exhibited low water solubility due to the lack of sugar moieties. Because of the large molecular weight of the tetracyclic triterpenoid saponins, ginsenosides have shown poor permeability.

Advanced delivery systems including nanostructured lipid carriers, self-microemulsifying systems, and specialized liposomes have overcome the major translational barrier of poor bioavailability, achieving up to 2.6-fold improvements and enabling clinical development.

8. Safety, Adverse Effects, and Drug Interactions

General Safety Profile

Studies on the safety of ginseng in randomized clinical trials covered efficacy in areas such as cardiovascular function, glucose metabolism, sexual function, anti-oxidation, anti-fatigue, and psychomotor function. Twenty-nine studies showed positive results, while fifteen studies showed no effect. Sixteen studies reported adverse events, while five studies had no adverse events.

While generally safe for consumption, several case reports and animal studies have indicated ginseng's potential to pose a variety of risks in vulnerable populations at high, prolonged doses, including hepatotoxicity, cardiovascular changes, mood disturbances, and hormonal effects.

Compound K Toxicology

The results of acute toxicity studies show that compound K administered orally to rats and mice did not cause mortality or toxicity at the maximum dosage of 8 g/kg and 10 g/kg, respectively. In a 26-week toxicity study, rats were administered CK at doses of 13, 40, or 120 mg/kg and observed for 26 weeks and a recovery period of four weeks. Under these conditions, asthenia, hypoactivity, loss of fur, and body weight reduction were transiently noticed in males of the 120 mg/kg group. Hepatotoxicity and nephrotoxicity were also evident, including elevation of liver and kidney relative weight, along with focal liver necrosis, as well as increases in plasma enzymes (ALT and ALP) in male rats receiving CK (120 mg/kg), but this toxicity appeared to be reversible.

Drug Interactions: Warfarin

Studies on the effect of Asian ginseng on the anticoagulant warfarin have had mixed results. Quality-control ginsenosides, extracted from ginseng and containing its major active ingredients, produce dose- and time-dependent antagonism in rats against warfarin's anti-coagulation assessed by INR and a rat thrombosis model. However, interaction with warfarin has been reported in some case reports, but it was also reported that there was no interaction with warfarin in healthy subjects and in patients receiving warfarin therapy. Although many case reports have reported on ginseng and drug interaction, the evidence is insufficient because the studies lack clear information on the samples which were combined with other herbs or on the condition of the participants.

Drug Interactions: Cytochrome P450

Cytochrome P450, located in the liver and responsible for the oxidative metabolism of most drugs, is inhibited by the intestinal metabolites of ginsenosides, including compound K and PPD, which may alter in vivo drug interactions.

Interactions with Cardiovascular and Other Medications

There are uncertainties about whether ginseng might interact with certain medications, such as calcium channel blockers and other high blood pressure medications, as well as statin medications and some antidepressants.

Standardization Challenges

Challenges persist in standardizing clinical applications due to variations in ginsenoside content and study methodologies. While current evidence supports P. ginseng's therapeutic potential, standardized clinical trials are essential to establish optimal dosing protocols and evaluate long-term safety. Although ginsenosides possess potent pharmacological activities in a variety of aspects, lack of standardization could be an obstacle for ginseng roots application in the clinic. Besides, due to the complexity of saponins, separation technique is unavailable to estimate all of the components in ginseng extracts, and whether other ingredients in ginseng extracts possess larger or synergistic antidiabetic activities is still unknown.

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• Pharmacological Properties of Ginsenoside Re — PMC/NCBI
• Immunomodulatory Activities of Emerging Rare Ginsenosides F1, Rg5, Rk1, Rh1, and Rg2 — PMC/NCBI
• Therapeutic potential of ginsenosides on diabetes: From hypoglycemic mechanism to clinical trials — ScienceDirect
• Therapeutic Potential of Ginsenosides as an Adjuvant Treatment for Diabetes — PMC/NCBI
• An 8-week, randomized, double-blind, placebo-controlled clinical trial for the antidiabetic effects of hydrolyzed ginseng extract — PMC/NCBI
• The Efficacy of Ginseng-Related Therapies in Type 2 Diabetes Mellitus: An Updated Systematic Review and Meta-analysis — PMC/NCBI
• Ginsenosides emerging as both bifunctional drugs and nanocarriers for enhanced antitumor therapies — PMC/NCBI
• Ginsenosides as Anticancer Agents: In vitro and in vivo Activities, Structure–Activity Relationships, and Molecular Mechanisms of Action — PMC/NCBI
• Ginsenosides: an immunomodulator for the treatment of colorectal cancer — PMC/NCBI
• Research Progress on Anticancer Mechanism of Ginsenoside Regulating Tumor Microenvironment — PMC/NCBI
• Anticancer Activities of Protopanaxadiol- and Protopanaxatriol-Type Ginsenosides and Their Metabolites — PMC/NCBI
• Functional Regulation of Ginsenosides on Myeloid Immunosuppressive Cells in the Tumor Microenvironment — PMC/NCBI
• Clinical and Preclinical Systematic Review of Panax ginseng C. A. Mey and Its Compounds for Fatigue — PMC/NCBI
• Efficacy of Ginseng Supplements on Fatigue and Physical Performance: a Meta-analysis — PMC/NCBI
• Safety Analysis of Panax Ginseng in Randomized Clinical Trials: A Systematic Review — PMC/NCBI
• Global deregulation of ginseng products may be a safety hazard to warfarin takers: solid evidence of ginseng-warfarin interaction — PMC/NCBI
• Herb-Drug Interactions: What the Science Says — NCCIH/NIH
• Single- and Multiple-Dose Trials to Determine the Pharmacokinetics, Safety, Tolerability, and Sex Effect of Oral Ginsenoside Compound K in Healthy Chinese Volunteers — Frontiers in Pharmacology
• Bioconversion, Pharmacokinetics, and Therapeutic Mechanisms of Ginsenoside Compound K and Its Analogues for Treating Metabolic Diseases — PMC/NCBI
• Preclinical safety of ginsenoside compound K: Acute, and 26-week oral toxicity studies in mice and rats — PubMed
• Pharmacokinetic variability of 20(S)-protopanaxadiol-type ginsenosides Rb1, Rd, and compound K from Korean red ginseng — Scientific Reports
• A Review of the Mechanisms and Risks of Panax ginseng in the Treatment of Alcohol Use Disorder — PMC/NCBI