Ginsenoside F1

Ginsenoside F1 at a Glance

Ginsenoside F1 is a minor protopanaxatriol (PPT)-type dammarane saponin of Asian ginseng (Panax ginseng). Structurally it is a single-glucose saponin — 20-O-β-D-glucopyranosyl-20(S)-protopanaxatriol — which makes it the PPT-branch structural twin of compound K, the well-known protopanaxadiol (PPD) metabolite ^{6Reference 6Jin S et al. · 2019Detection of 13 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K, 20(S)-protopanaxadiol, and 20(S)-protopanaxatriol) in human plasma and application of the analytical method to human pharmacokinetic studies following two-week repeated administration of red ginseng extract — human PKView study →}.

Unlike the two headline ginseng saponins Rg1 and Rb1, F1 is barely present in the raw root — it is chiefly a metabolite formed when gut bacteria (or enzymatic processing) strip sugars from Re and Rg1 ^{7,8Reference 7He C et al. · 2016AnimalSimultaneous quantification of ginsenoside Rg1 and its metabolites by HPLC-MS/MS: Rg1 excretion in rat bile, urine and feces — animal modelView study →Reference 8Won HJ et al. · 2019ReviewNon-clinical pharmacokinetic behavior of ginsenosides — reviewView study →}. Its distinctive research niche is skin: the most-cited F1 work is isolate studies of keratinocyte photoprotection and skin-whitening, where purified F1 is applied topically rather than swallowed ^{1,2Reference 1Lee EH et al. · 2003In vitroGinsenoside F1 protects human HaCaT keratinocytes from ultraviolet-B-induced apoptosis by maintaining constant levels of Bcl-2 — in vitroView study →Reference 2Lee CS et al. · 2019In vitroWhitening efficacy of ginsenoside F1 through inhibition of melanin transfer in cocultured human melanocytes–keratinocytes and three-dimensional human skin equivalent — in vitroView study →}.

The honest posture throughout is that F1’s evidence is entirely preclinical and isolate-based — cell cultures, reconstructed-skin models and mice — and that native F1 levels are too low for ordinary ginseng intake to deliver it in any quantity. There is no human trial of the isolated molecule.

The PPT-Side Metabolite (Re/Rg1 → F1)

Ginseng’s dammarane saponins split into two families defined by their aglycone (sapogenin): the protopanaxadiol (PPD) series (Rb1, Rb2, Rc, Rd…) and the protopanaxatriol (PPT) series (Re, Rg1, Rf…), the latter carrying an extra hydroxyl at C-6. Gut bacteria progressively deglycosylate both families, and the two branches have famous near-terminal monoglucosides:

PPD branch → compound K = 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol.
PPT branch → ginsenoside F1 = 20-O-β-D-glucopyranosyl-20(S)-protopanaxatriol.

The two molecules are the same C-20 monoglucoside on the two different skeletons — F1 is, quite literally, “compound K with the extra triol hydroxyl.” That parallel is the cleanest way to place F1 ^{6Reference 6Jin S et al. · 2019Detection of 13 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K, 20(S)-protopanaxadiol, and 20(S)-protopanaxatriol) in human plasma and application of the analytical method to human pharmacokinetic studies following two-week repeated administration of red ginseng extract — human PKView study →}.

The honest complication is metabolic prominence. Compound K is the dominant PPD metabolite that actually reaches the blood. On the PPT branch, the analogous headline human metabolites are ginsenoside Rh1 (the C-6 monoglucoside) and free protopanaxatriol — F1 (the C-20 monoglucoside) is the minor, more rat-associated route off the same tree ^{7,8Reference 7He C et al. · 2016AnimalSimultaneous quantification of ginsenoside Rg1 and its metabolites by HPLC-MS/MS: Rg1 excretion in rat bile, urine and feces — animal modelView study →Reference 8Won HJ et al. · 2019ReviewNon-clinical pharmacokinetic behavior of ginsenosides — reviewView study →}. So F1 is the PPT-side structural counterpart of compound K, not its metabolic equal: it is the triol-branch endpoint you write on the diagram, not the one your gut mostly makes.

What gives F1 its own identity is where it has been studied. Its best-developed literature is dermatological isolate work — protecting keratinocytes from UV damage and interfering with skin pigmentation ^{1,2,3Reference 1Lee EH et al. · 2003In vitroGinsenoside F1 protects human HaCaT keratinocytes from ultraviolet-B-induced apoptosis by maintaining constant levels of Bcl-2 — in vitroView study →Reference 2Lee CS et al. · 2019In vitroWhitening efficacy of ginsenoside F1 through inhibition of melanin transfer in cocultured human melanocytes–keratinocytes and three-dimensional human skin equivalent — in vitroView study →Reference 3Lee JE et al. · 2017In vitroInhibitory effects of ginsenosides on basic fibroblast growth factor-induced melanocyte proliferation — in vitroView study →} — applications delivered by applying purified F1 to skin, which sidesteps the poor-oral-absorption problem that dogs the parent saponins. The catch: because raw ginseng contains so little F1, this is isolate science, not a property you get from a cup of ginseng tea.

What It's Used For

F1’s evidence base is small, recent and consistent in one respect: nearly every study uses the isolated (often enzymatically prepared) molecule in cells, reconstructed skin or mice. The strongest lines are dermatological; a separate immunology thread reports NK-cell enhancement.

Best-developed (preclinical):keratinocyte photoprotection — isolated F1 protects human HaCaT keratinocytes from UVB-induced apoptosis by preventing the UV-driven downregulation of the anti-apoptotic protein Bcl-2 (and Brn-3a), blocking PARP cleavage ^{1Reference 1Lee EH et al. · 2003In vitroGinsenoside F1 protects human HaCaT keratinocytes from ultraviolet-B-induced apoptosis by maintaining constant levels of Bcl-2 — in vitroView study →}.

A coherent skin-whitening line:isolated F1 inhibits melanin transfer from melanocytes to keratinocytes in cocultures and in a 3D human-skin equivalent ^{2Reference 2Lee CS et al. · 2019In vitroWhitening efficacy of ginsenoside F1 through inhibition of melanin transfer in cocultured human melanocytes–keratinocytes and three-dimensional human skin equivalent — in vitroView study →}, and (with Rh3) suppresses bFGF-driven ERK→MITF melanocyte proliferation ^{3Reference 3Lee JE et al. · 2017In vitroInhibitory effects of ginsenosides on basic fibroblast growth factor-induced melanocyte proliferation — in vitroView study →}.

An immunology thread:across 15 ginsenosides screened, isolated F1 most potently raised NK-cell cytotoxicity via an IGF-1-dependent mechanism and improved tumour clearance in NK-dependent mouse melanoma/lymphoma models ^{4Reference 4Kwon HJ et al. · 2018In vitroGinsenoside F1 promotes cytotoxic activity of NK cells via insulin-like growth factor-1-dependent mechanism — in vitro and animal modelView study →}; reviews also credit F1 with macrophage-phagocytosis/MAPK–NF-κB effects ^{5Reference 5Hong CE · 2025ReviewImmunomodulatory activities of emerging rare ginsenosides F1, Rg5, Rk1, Rh1, and Rg2: from molecular mechanisms to therapeutic applications — reviewView study →}.

The caveats:native F1 is trace in ginseng, so oral ginseng doesn’t deliver it ^{6,8Reference 6Jin S et al. · 2019Detection of 13 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K, 20(S)-protopanaxadiol, and 20(S)-protopanaxatriol) in human plasma and application of the analytical method to human pharmacokinetic studies following two-week repeated administration of red ginseng extract — human PKView study →Reference 8Won HJ et al. · 2019ReviewNon-clinical pharmacokinetic behavior of ginsenosides — reviewView study →}; all data are isolate + preclinical; there is no human trial of F1 itself.

Evidence by IndicationStrength of support · Beta

Support is an experimental score — weighted by study type (human > animal > in vitro) and volume, tempered for isolate-vs-plant match and bioavailability. A beta, not a validated metric. Every row rests on isolated F1 in cells, reconstructed skin or mice (no human data), so scores are capped accordingly. Each application links to its write-up.

Mechanisms

Target / pathway	Effect	Relevant to
Bcl-2 (anti-apoptotic)	blocks UVB-induced downregulation of Bcl-2 (does not itself induce it); prevents PARP cleavage	skin photoprotection
Brn-3a	preserves expression under UVB, supporting keratinocyte survival	skin photoprotection
Melanosome / melanin transfer (melanocyte → keratinocyte)	inhibits pigment transfer to keratinocytes → depigmenting effect	skin whitening
ERK → MITF	with Rh3, suppresses bFGF-driven ERK phosphorylation and MITF, curbing melanocyte proliferation	skin whitening
NK-cell cytotoxic program via IGF-1	raises cytotoxic mediators / activation signals → enhanced tumour-cell killing	immune surveillance
MAPK / NF-κB (macrophage)	reported enhancement of phagocytosis / immune activation	immune surveillance

The dermatological mechanisms are the load-bearing ones — F1 is applied topically as an isolate, which is why its skin data are more interpretable than an oral-ginseng inference. The IGF-1/NK axis is elegant but preclinical and double-edged.

Pharmacokinetics

F1 is a monoglucosyl PPT saponin — one sugar on the protopanaxatriol aglycone — so it is smaller and more lipophilic than the tri-glycosylated parents Rg1/Re, and correspondingly better able to cross membranes than they are. The practical problem is supply, not permeability: native F1 is trace in ginseng, and on the PPT deglycosylation branch the human gut preferentially generates Rh1 and free protopanaxatriol rather than F1 (F1 is more prominent in rat intestine) ^{7,8Reference 7He C et al. · 2016AnimalSimultaneous quantification of ginsenoside Rg1 and its metabolites by HPLC-MS/MS: Rg1 excretion in rat bile, urine and feces — animal modelView study →Reference 8Won HJ et al. · 2019ReviewNon-clinical pharmacokinetic behavior of ginsenosides — reviewView study →}. In a two-week repeated-dose human study using a validated 13-analyte assay, F1 was among the ginsenosides that appear in plasma only at low/trace levels after red-ginseng intake ^{6Reference 6Jin S et al. · 2019Detection of 13 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K, 20(S)-protopanaxadiol, and 20(S)-protopanaxatriol) in human plasma and application of the analytical method to human pharmacokinetic studies following two-week repeated administration of red ginseng extract — human PKView study →}. There is no dedicated human pharmacokinetic study of isolated F1; its topical/cosmetic use deliberately bypasses the oral route. The upshot mirrors the rest of the class: an oral ginseng dose does not deliver meaningful F1, and F1’s own pharmacology has been read from applied-isolate experiments, not systemic exposure.

Clinical Trials

There are no registered trials of isolated ginsenoside F1. All human ginseng evidence is at the whole-extract level, where F1 is a negligible constituent, so no clinical outcome can be attributed to it. The F1-specific literature is entirely preclinical (cells, reconstructed skin, mice).

Completed	Planned	Terminated	Preclinical
None(isolated F1)	None identified	None	Skin(photoprotection, whitening) + NK/immune

Last checked: July 2026.

Isolate vs. Plant Studies

F1 is an unusually clean example of isolate-only evidence. Every result above uses the purified molecule — often enzymatically biotransformed F1 — in HaCaT keratinocytes, melanocyte cocultures, 3D skin equivalents or mice ^{1,2,3,4Reference 1Lee EH et al. · 2003In vitroGinsenoside F1 protects human HaCaT keratinocytes from ultraviolet-B-induced apoptosis by maintaining constant levels of Bcl-2 — in vitroView study →Reference 2Lee CS et al. · 2019In vitroWhitening efficacy of ginsenoside F1 through inhibition of melanin transfer in cocultured human melanocytes–keratinocytes and three-dimensional human skin equivalent — in vitroView study →Reference 3Lee JE et al. · 2017In vitroInhibitory effects of ginsenosides on basic fibroblast growth factor-induced melanocyte proliferation — in vitroView study →Reference 4Kwon HJ et al. · 2018In vitroGinsenoside F1 promotes cytotoxic activity of NK cells via insulin-like growth factor-1-dependent mechanism — in vitro and animal modelView study →}. There is no “whole-plant F1” story to transfer, because raw ginseng contains so little F1 that ordinary intake cannot supply it ^{6,8Reference 6Jin S et al. · 2019Detection of 13 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K, 20(S)-protopanaxadiol, and 20(S)-protopanaxatriol) in human plasma and application of the analytical method to human pharmacokinetic studies following two-week repeated administration of red ginseng extract — human PKView study →Reference 8Won HJ et al. · 2019ReviewNon-clinical pharmacokinetic behavior of ginsenosides — reviewView study →}. That cuts two ways. For the topical skin applications it is a genuine strength: F1 is used the way it is studied — as an applied isolate at defined concentrations, not inferred from an extract. For any systemic claim it is a hard limit: ginseng’s human benefits belong to standardised extracts and to more abundant saponins, and cannot be re-attributed to a trace metabolite. F1 reaching a person in quantity essentially requires deliberate enrichment (fermented/enzyme-processed ginseng) or a manufactured ingredient, not the herb itself.

Prevalence in Nature

In unprocessed ginseng root, F1 is trace to near-absent — it is not one of the stored marker saponins like Rb1, Rg1 or Re. Instead it arises as a deglycosylation metabolite of the protopanaxatriol saponins Re and Rg1, produced by intestinal bacteria in vivo and by the β-glucosidase activity used in fermentation and enzymatic processing of ginseng ^{7,8Reference 7He C et al. · 2016AnimalSimultaneous quantification of ginsenoside Rg1 and its metabolites by HPLC-MS/MS: Rg1 excretion in rat bile, urine and feces — animal modelView study →Reference 8Won HJ et al. · 2019ReviewNon-clinical pharmacokinetic behavior of ginsenosides — reviewView study →}. Enzyme- or ferment-treated (“rare-ginsenoside-enriched”) products therefore carry more F1 than the raw herb, but even there it is a minor component alongside Rh1, Rg2, Rg3, compound K and the free aglycones. Because it is a metabolite rather than a phytochemical the plant accumulates, F1 has no meaningful “richest natural source” — its abundance is a function of processing and gut metabolism, not botanical origin.

Discovery & Synthesis

F1 was characterised as one of the minor protopanaxatriol ginsenosides / deglycosylation products of the ginseng saponin pool; its scientific profile is defined less by a first-isolation milestone than by the 2003 keratinocyte photoprotection study of Lee and colleagues, which used enzymatically prepared F1 from purified ginseng saponin and put the molecule on the dermatology map ^{1Reference 1Lee EH et al. · 2003In vitroGinsenoside F1 protects human HaCaT keratinocytes from ultraviolet-B-induced apoptosis by maintaining constant levels of Bcl-2 — in vitroView study →}. It carries CAS number 53963-43-2.

Manufacture today is overwhelmingly by biotransformation: because native yields are so low, F1 is produced by treating the abundant parent saponins (Re/Rg1) or crude ginseng saponin with β-glucosidase enzymes or microbial fermentation to strip sugars down to the monoglucoside — the same enzymatic strategy used across the “rare ginsenoside” ingredient sector. This is why F1 shows up as a cosmetic/nutraceutical isolate rather than a plant extract fraction.

Patents: not yet researched.

Toxicity & Safety

F1 carries a low flag, consistent with the ginsenoside class and with the favourable tolerability noted in the NK-cell work ^{4Reference 4Kwon HJ et al. · 2018In vitroGinsenoside F1 promotes cytotoxic activity of NK cells via insulin-like growth factor-1-dependent mechanism — in vitro and animal modelView study →}. It is a minor metabolite that humans are already exposed to at trace levels via ginseng, and its poor native abundance keeps ordinary systemic exposure minimal. The honest qualifier is that no dedicated toxicology package (repeat-dose, genotoxicity, reproductive) exists for the isolated molecule, so “low” reflects class behaviour and the absence of adverse signals rather than a completed safety dossier.

Safety at a Glance

Low / no toxicity

Class-typical low toxicity. A minor ginsenoside metabolite with no adverse signals reported in the available preclinical work; favourable tolerability in the NK-cell study.
All benefits are isolate + preclinical. Skin and immune effects come from cells, reconstructed skin and mice — not human trials; do not read them as proven in people.
Pro-IGF-1 / pro-immune direction is double-edged. F1’s NK/IGF-1 mechanism is not uniformly desirable, and its interaction profile in humans is uncharacterised.
No dedicated isolate toxicology. No repeat-dose, genotoxicity or reproductive dataset for pure F1; safety here is inferred from the class.

Dosage

There is no established human dose of isolated ginsenoside F1. The figures in the literature are experimental: micromolar concentrations applied to keratinocytes, melanocytes and 3D skin models in the dermatological studies ^{1,2,3Reference 1Lee EH et al. · 2003In vitroGinsenoside F1 protects human HaCaT keratinocytes from ultraviolet-B-induced apoptosis by maintaining constant levels of Bcl-2 — in vitroView study →Reference 2Lee CS et al. · 2019In vitroWhitening efficacy of ginsenoside F1 through inhibition of melanin transfer in cocultured human melanocytes–keratinocytes and three-dimensional human skin equivalent — in vitroView study →Reference 3Lee JE et al. · 2017In vitroInhibitory effects of ginsenosides on basic fibroblast growth factor-induced melanocyte proliferation — in vitroView study →}, and preclinical doses in the mouse NK/immune work ^{4Reference 4Kwon HJ et al. · 2018In vitroGinsenoside F1 promotes cytotoxic activity of NK cells via insulin-like growth factor-1-dependent mechanism — in vitro and animal modelView study →}. Where F1 appears in commerce it is as a topical cosmetic ingredient at manufacturer-set concentrations, not a standardised oral supplement. Oral ginseng products are standardised to the abundant marker saponins (Rg1, Rb1, Re), not to F1, which they contain only in traces ^{6Reference 6Jin S et al. · 2019Detection of 13 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K, 20(S)-protopanaxadiol, and 20(S)-protopanaxatriol) in human plasma and application of the analytical method to human pharmacokinetic studies following two-week repeated administration of red ginseng extract — human PKView study →}.

These are concentrations and doses studied in research, and are not a personal recommendation.

References

Lee EH, Cho SY, Kim SJ, Shin ES, Chang HK, Kim DH, Yeom MH, Woe KS, Lee J, Sim YC, Lee TR. (2003). Ginsenoside F1 protects human HaCaT keratinocytes from ultraviolet-B-induced apoptosis by maintaining constant levels of Bcl-2 — in vitro. Journal of Investigative Dermatology, 121(3), 607–613. https://pubmed.ncbi.nlm.nih.gov/12925222/
Lee CS, Nam G, Bae IH, Park J. (2019). Whitening efficacy of ginsenoside F1 through inhibition of melanin transfer in cocultured human melanocytes–keratinocytes and three-dimensional human skin equivalent — in vitro. Journal of Ginseng Research, 43(2), 300–304. https://pubmed.ncbi.nlm.nih.gov/30962737/
Lee JE, Park JI, Myung CH, Hwang JS. (2017). Inhibitory effects of ginsenosides on basic fibroblast growth factor-induced melanocyte proliferation — in vitro. Journal of Ginseng Research, 41(3), 268–276. https://pubmed.ncbi.nlm.nih.gov/28701866/
Kwon HJ, Lee H, Choi GE, Kwon SJ, Song AY, Kim SJ, Choi WS, Hwang SH, Kim SC, Kim HS. (2018). Ginsenoside F1 promotes cytotoxic activity of NK cells via insulin-like growth factor-1-dependent mechanism — in vitro and animal model. Frontiers in Immunology, 9, 2785. https://pubmed.ncbi.nlm.nih.gov/30546365/
Hong CE, Lyu SY. (2025). Immunomodulatory activities of emerging rare ginsenosides F1, Rg5, Rk1, Rh1, and Rg2: from molecular mechanisms to therapeutic applications — review. Pharmaceuticals, 18(10), 1529. https://pubmed.ncbi.nlm.nih.gov/41155644/
Jin S, Jeon JH, Lee S, Kang WY, Seong SJ, Yoon YR, Choi MK, Song IS. (2019). Detection of 13 ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K, 20(S)-protopanaxadiol, and 20(S)-protopanaxatriol) in human plasma and application of the analytical method to human pharmacokinetic studies following two-week repeated administration of red ginseng extract — human PK. Molecules, 24(14), 2618. https://pubmed.ncbi.nlm.nih.gov/31323835/
He C, Feng R, Sun Y, Chu S, Chen J, Ma C, Fu J, Zhao Z, Huang M, Shou J, Li X, Wang Y, Hu J, Wang Y, Zhang J. (2016). Simultaneous quantification of ginsenoside Rg1 and its metabolites by HPLC-MS/MS: Rg1 excretion in rat bile, urine and feces — animal model. Acta Pharmaceutica Sinica B, 6(6), 595–602. https://pubmed.ncbi.nlm.nih.gov/27818927/
Won HJ, Kim HI, Park T, Kim H, Jo K, Jeon H, Ha SJ, Hyun JM, Jeong A, Kim JS, Park YJ, Eo YH, Lee J. (2019). Non-clinical pharmacokinetic behavior of ginsenosides — review. Journal of Ginseng Research, 43(3), 354–360. https://pubmed.ncbi.nlm.nih.gov/31308806/
You L, Cho JY. (2021). The regulatory role of Korean ginseng in skin cells — review. Journal of Ginseng Research, 45(3), 363–370. https://pubmed.ncbi.nlm.nih.gov/34025129/