Tremella

Metadata

Regulatory Status

Chinese Pharmacopoeia

• Listed: Yes. Bai Mu Er (Tremella) is an official drug in the Chinese Pharmacopoeia (2020 edition).
• Traditional indications: Nourishing yin, moistening the lungs, nourishing the stomach, and generating fluids (sheng jin). Used for dry cough, blood in sputum, and deficiency of stomach yin.
• Classification: Yin-nourishing tonic. Sweet and bland in taste, neutral in nature. Enters the Lung, Stomach, and Kidney meridians.
• Historical significance: Tremella was historically reserved for the imperial court in China. It was a key ingredient in Yang Guifei’s (Tang Dynasty imperial consort, 719-756 CE) beauty regimen, consumed as a sweetened soup (Yin Er Tang) for maintaining youthful skin.

Japan

• Recognition: Shirokikurage is used in Japanese traditional medicine and widely consumed as a health food. Not listed as an official drug in the Japanese Pharmacopoeia.

Korea

• Recognition: Used in Korean traditional medicine as a yin-nourishing and lung-moistening agent.

European Union

• Novel Food: No specific novel food authorization as an isolated extract. The whole fruiting body has a history of consumption in the EU as an imported food ingredient.
• Cosmetic use: Tremella polysaccharide extracts are widely used in EU-marketed cosmetic and skincare products under the EU Cosmetics Regulation (EC) No 1223/2009.

United States

• Dietary supplement: Marketed under DSHEA (1994). Available in capsule, powder, and liquid extract forms.
• Cosmeceutical market: Increasingly marketed as a natural alternative to hyaluronic acid in skincare formulations.

Conditions & Indications

Primary Indications (Moderate Evidence)

• Skin hydration and moisture retention — Tremella glucuronoxylomannan polysaccharides form a flexible, hydrophilic film that can hold up to approximately 500 times its dry weight in water, comparable to or exceeding hyaluronic acid in in vitro studies (Huang et al., 2002). Smaller particle size allows improved skin penetration compared to hyaluronic acid (Yang & He, 2008).
• Antioxidant and anti-aging activity — Tremella polysaccharides demonstrate potent free radical scavenging activity in vitro. In UV-irradiation models, Tremella polysaccharide extracts reduced markers of photoaging and collagen degradation (Park et al., 2014).
• Yin deficiency with dryness symptoms (TCM) — Traditional primary indication for conditions characterized by dryness: dry cough, dry skin, dry mouth and throat, and general depletion of body fluids.

Secondary Indications (Preliminary Evidence)

• Immunomodulation — Tremella polysaccharides activate macrophages and enhance splenocyte proliferation. Gao et al. (1996) demonstrated stimulation of macrophage phagocytic activity and cytokine production in murine models.
• Respiratory support and lung moistening — Traditional TCM indication for dry cough and deficiency-type respiratory complaints.
• Neuroprotective effects — Kim et al. (2007) demonstrated neuroprotective activity against beta-amyloid-induced neurotoxicity in primary rat cortical neurons.

Emerging/Preclinical Indications

• Wound healing — Tremella polysaccharides accelerated wound closure in in vitro scratch assays and in vivo models.
• Gut microbiome modulation — Prebiotic polysaccharides promote Bifidobacterium and Lactobacillus growth in animal models.
• Hypoglycemic and hypolipidemic activity — Cho et al. (2007) demonstrated that Tremella exopolysaccharides reduced blood glucose in ob/ob mice.

Mechanism of Action

Primary Mechanisms

1. Glucuronoxylomannan polysaccharide moisture retention The signature bioactivity derives from unique acidic heteropolysaccharides consisting of alpha-1,3-linked mannose backbones with side chains of xylose, glucuronic acid, and fucose. The abundant glucuronic acid residues confer strong negative charge, creating an extensive hydration shell with water-binding capacity comparable to hyaluronic acid (approximately 450-500 times dry weight). Smaller molecular weight (10-500 kDa versus 1,000-8,000 kDa for high-MW hyaluronic acid) enables superior skin penetration for topical applications.

2. Antioxidant and anti-photoaging activity Tremella polysaccharides demonstrate direct free radical scavenging against superoxide anion, hydroxyl radical, and DPPH radicals. In UV-irradiation models, treatment reduces MMP-1 and MMP-3 expression, protecting collagen and elastin from enzymatic degradation through suppression of AP-1 and NF-kB signaling.

3. Immunomodulatory polysaccharide signaling Polysaccharides activate innate immune cells through TLR-2 and Dectin-1 on macrophages and dendritic cells. Tremella polysaccharides also enhance splenic T and B lymphocyte proliferation and NK cell activity in immunosuppressed animal models.

Key Active Compounds

Pharmacological Note

Tremella is pharmacologically distinct from most other medicinal mushrooms in that its primary bioactive mechanism is physical-chemical moisture retention driven by glucuronoxylomannan polysaccharides, rather than immune modulation. While it shares immunomodulatory beta-glucan activity common to Basidiomycetes, this is a secondary mechanism. The TCM classification as a yin-nourishing, fluid-generating agent is remarkably consistent with modern understanding of its polysaccharide hydration chemistry. Unlike reishi or chaga, there is minimal triterpenoid content.

Clinical Evidence Summary

Reviews

Key Individual Studies

Evidence Limitations

• Near-complete absence of randomized, placebo-controlled clinical trials for skin-specific outcomes in humans.
• In vitro water-holding capacity does not directly translate to clinical skin hydration after oral consumption.
• Most preclinical studies used isolated polysaccharide fractions that may not correspond to commercial supplements.
• Immunomodulatory effects demonstrated primarily in immunosuppressed animal models.
• Publication bias toward positive results in the Chinese-language literature is a concern.

Safety Profile

General Assessment

Excellent safety record based on centuries of culinary and medicinal use across East Asia. Widely consumed as a food in soups, desserts, and beverages. No significant adverse events reported in the published literature.

Contraindications

• Known allergy to Tremella species: Rare but documented.
• Immunosuppressed patients: Theoretical precaution given immunomodulatory activity.

Drug Interactions

• No clinically significant drug interactions documented. This favorable profile distinguishes Tremella from more pharmacologically potent medicinal mushrooms.
• Theoretical: Mild hypoglycemic activity in animal studies suggests monitoring blood glucose in diabetic patients on concurrent medication, though clinical relevance at typical doses is low.

Side Effects

• Common: None reported at standard doses.
• Uncommon: Mild GI discomfort (bloating, loose stools) with high doses, attributable to high soluble fiber content.
• Rare: Isolated allergic reactions.

Pregnancy and Lactation

• Category: Likely safe as a culinary food. Consumed by pregnant women in China for centuries without documented adverse effects. Concentrated supplement use should be approached with standard precaution.

Clinical Dosage

Dried Fruiting Body (Culinary / Traditional Use)

• Standard dose: 3-10 g/day of dried fruiting body, rehydrated and prepared as soup or dessert
• Traditional preparation: Soak in water 1-2 hours until expanded, simmer 30-60 minutes with rock sugar, jujube dates, and goji berries (Yin Er Tang)
• Note: Dried fruiting body expands ~10-15 times its dry volume

Polysaccharide Extract (Oral Supplement)

• Standard dose: 1-3 g/day standardized to polysaccharide content (30-50%)
• Available forms: Capsules, powder, liquid extract

Topical Application (Cosmeceutical)

• Standard concentration: 0.05-1% Tremella polysaccharide extract in skincare formulations
• Application: Applied to clean skin once or twice daily
• Note: Used as a natural alternative to or complement to hyaluronic acid; smaller molecular weight may allow enhanced penetration

Powdered Fruiting Body

• Standard dose: 1-3 g/day in capsules or mixed into beverages

Sources

• Huang HC, Chen TH, Chou SM, et al. Isolation of water-soluble polysaccharides from Tremella fuciformis and their moisture-retaining activity. Journal of the Chinese Chemical Society. 2002;49(4):583-588
• Yang L, He QS. Research on the moisture-retention and skin-penetrating properties of Tremella polysaccharide. Journal of Cosmetic Science. 2008;59(1):1-10
• Park HJ, Shim HS, Kim KS, Shim I. The protective effect of Tremella fuciformis extract on the skin of UVB-irradiated hairless mice. Korean Journal of Physiology and Pharmacology. 2014;18(5):381-386
• Gao QP, Seljelid R, Chen HY, Jiang R. Characterization of acidic heteroglycans from Tremella fuciformis Berk. with cytokine stimulating activity. Carbohydrate Research. 1996;288:135-142
• Kim JH, Ha HC, Lee MS, et al. Effect of Tremella fuciformis on the neurotoxicity induced by beta-amyloid peptide in primary rat cortical cells. Biological and Pharmaceutical Bulletin. 2007;30(6):1121-1126
• Cho EJ, Hwang HJ, Kim SW, et al. Hypoglycemic effects of exopolysaccharides produced by mycelial culture of two different mushrooms Tremella fuciformis and Phellinus baumii in ob/ob mice. Applied Microbiology and Biotechnology. 2007;75(6):1257-1265
• Wu YJ, Wei ZX, Zhang FM, et al. Structure, bioactivities and applications of the polysaccharides from Tremella fuciformis mushroom: a review. International Journal of Biological Macromolecules. 2019;121:1005-1010
• Venturella G, Ferraro V, Cirlincione F, Gargano ML. Medicinal mushrooms: bioactive compounds, use, and clinical trials. International Journal of Molecular Sciences. 2021;22(2):634
• Chinese Pharmacopoeia Commission. Pharmacopoeia of the People’s Republic of China. Vol 1. 2020 Edition
• Wasser SP. Medicinal mushrooms as a source of antitumor and immunomodulating polysaccharides. Applied Microbiology and Biotechnology. 2002;60(3):258-274

Connections

• Compare with Reishi (Ganoderma lucidum): both are cornerstone TCM tonic mushrooms, but reishi acts primarily through immune modulation and triterpenoid anti-inflammatory activity, while Tremella acts through polysaccharide-driven moisture retention and yin nourishment. The two are frequently combined in traditional beauty and longevity formulations.
• The glucuronoxylomannan polysaccharides in Tremella are structurally distinct from the beta-1,3/1,6-D-glucans that drive immunomodulation in Turkey Tail, Maitake, and Shiitake. Tremella’s polysaccharides are acidic heteropolysaccharides with mannose backbones, explaining the different primary bioactivity (moisture retention vs. immune stimulation).
• Lion’s Mane and Tremella share preclinical neuroprotective evidence, though through different mechanisms: Lion’s Mane via NGF/BDNF stimulation, Tremella via antioxidant-mediated neuroprotection against beta-amyloid toxicity.
• Tremella’s positioning in the skin-beauty category is unique among the medicinal mushrooms; no other monographed species has moisture retention as its primary mechanism, making it a complementary addition to mushroom wellness protocols.
• Traditional synergy: Tremella is classically paired with goji berries, jujube dates, lotus seeds, and rock sugar in Yin Er Tang soup, which serves as both a beauty food and yin-nourishing medicinal preparation in TCM.