What Is Snow Fungus (Tremella) Good For? The Two Trials

Snow fungus (Tremella fuciformis) is a white jelly fungus eaten in Chinese desserts and sold in the UK dried, powdered, in capsules, blends and gummies. Two small human trials exist: 75 adults with memory complaints took 600 or 1,200 mg a day for eight weeks, and 56 adults with prediabetes drank a daily tremella beverage for 12 weeks.^{1, 2} It has not been tested in people for skin, and it contains no collagen. It sits in our guide to whether mushroom supplements work.

What is snow fungus, and is it the same as tremella?

Yes. Snow fungus is the common name for Tremella fuciformis, also sold as silver ear, white fungus or snow mushroom. It is a jelly fungus that grows on dead broadleaf wood in warm, humid climates and is farmed, mostly in China, then sold dried in pale, crinkled heads that swell to several times their size when soaked. In Chinese cooking it is a dessert ingredient first, simmered with pear, red dates or rock sugar into a sweet soup with a slippery, almost flavourless texture. Tremella mesenterica, "yellow brain", an orange jelly fungus found on dead branches across Britain, is a different species, and its one human study is covered below.³ For mushrooms generally as food, see are mushrooms good for you.

Is snow fungus good for the brain or memory?

One trial has asked. Ban and colleagues in Korea randomised 75 adults with subjective cognitive impairment, people who felt their memory was slipping without a diagnosis, to 600 mg a day of Tremella fuciformis (30 people), 1,200 mg a day (30) or placebo (15) for eight weeks, double-blind.¹ The primary outcome was a questionnaire of memory complaints, and its scores improved more in the tremella groups than on placebo; standardised tests of short-term memory and executive function also improved more than placebo. Adverse events were equally common in every arm: 40.4% at the higher dose, 35.1% at the lower, 41.4% on placebo. The abstract gives no figures for the size of any difference. That is one eight-week trial, with a 15-person placebo arm and a self-rated primary outcome, that has not been repeated. Snow fungus has not been tested in people with a memory diagnosis, in healthy adults or beyond eight weeks.

Does snow fungus affect blood sugar or weight?

Gitsomboon and colleagues in Thailand gave 56 overweight or obese adults with prediabetes a once-daily tremella beverage or a placebo drink for 12 weeks, double-blind.² In the tremella group, HbA1c, the three-month average of blood glucose, moved from 6.03% to 5.96% (p = 0.047), and waist circumference from 95.2 cm to 93.5 cm (p = 0.022). No adverse events were reported. The authors call the study exploratory, and the changes are within-group figures: a 0.07 percentage-point shift in HbA1c, from a drink whose tremella content the abstract does not state. Nothing here changes the plan your GP or diabetes team has set, and because no study has tested snow fungus alongside any diabetes medicine, tell the team before adding it.

Is snow fungus good for your skin, and is it "vegan collagen"?

Snow fungus has not been tested in people for skin. No trial has measured hydration, wrinkles or elasticity. The phrases that sell it, "beauty mushroom", "nature's hyaluronic acid" and "vegan collagen", come from laboratory work: its polysaccharides are long sugar chains that bind many times their weight in water in a dish, which is why it appears in face creams. Holding water in a dish is not evidence of holding water in skin, and no study has compared tremella with hyaluronic acid in people. On collagen the answer is simpler: collagen is an animal protein, no plant, fungus or seaweed makes it, so snow fungus contains none. See what foods are high in collagen (no plant or fungus contains it) and, for what the products sold as vegan collagen actually hold, is there a vegan collagen.

What about the other tremella studies?

Two more studies mention tremella; neither can be credited to it. A 2023 Taiwanese trial gave 64 adults a drink combining fish roe, snow fungus and yeast, or a placebo, for eight weeks; the formula group recalled more memory cards and reacted faster in cognitive tests.⁴ Three ingredients went in together, so the result belongs to the formula, not to snow fungus. A 2012 study in Israel gave 52 patients with Helicobacter pylori infection tablets of Tremella mesenterica, the yellow brain species, 2 g twice a day for ten days, against standard triple therapy.³ Triple therapy cleared the infection in 70% of its patients; among everyone on tremella, one person cleared it, and the authors' own title calls the mushroom "subjectively but not objectively effective". A null result in a different species cannot be carried over to snow fungus, so this page reports it as a null, not as a tremella benefit.

Is snow fungus safe, and who should ask first?

As a cooked food, snow fungus has a long record in East Asian kitchens and is not poisonous; the people who cannot eat it are those with a mushroom allergy. As a supplement the record is two trials: adverse events were common in all three arms of the memory trial, placebo included, and the 12-week beverage trial reported none.^{1, 2} That is 131 people for at most 12 weeks; longer use is untested. Interactions are unstudied: no study has paired tremella with a diabetes medicine, an anticoagulant, an antiplatelet or any medicine that acts on the immune system, and fungal beta-glucans changed immune markers in blood tests in trials of other species, so anyone on transplant medicines, biologics, chemotherapy or immunotherapy asks the specialist first; the cross-species medicine table marks every pairing known, theoretical or unstudied. Tell the pre-operative assessment team about every supplement before an operation. No trial included anyone pregnant or breastfeeding, or under 18, so there is no data for them, and the NHS says of herbal medicines generally that they "are not recommended for children. This is because not enough is known about their safety."⁵ Stop and speak to a pharmacist or GP if you feel unwell, and report a suspected reaction through the MHRA Yellow Card scheme.⁶

What is the UK position on snow fungus?

Snow fungus is a food, not a medicine, and no supplement may attach a health benefit to it. The Great Britain nutrition and health claims register holds no authorised claim for any mushroom and no row at all for Tremella.⁷ The Advertising Standards Authority's guidance of 21 November 2024 said "there are no authorised claims for mushrooms themselves". The FSA's list of GB novel-food consultation outcomes contains no mushroom other than enriched button mushrooms, so tremella's position is inferred from the EU consultations GB tracks, which class a mushroom's fruiting body and water extracts as not novel and mycelium products as novel; no GB body has stated a position on snow fungus itself (GB position inferred).^{8, 9} In the UK it is sold mostly inside multi-mushroom gummies and blends; do mushroom gummies work shows how to turn a label's ratio into milligrams and set them beside the 600 to 1,200 mg a day the memory trial used.

How is snow fungus sold: dried, powder, capsule, blend or gummy?

Each form says something different on its label. Dried whole fungus from a grocer is a food: soak, trim the hard base and simmer; there is no dose because it is an ingredient. A powder states grams per scoop and whether it is ground fruiting body or an extract with a ratio such as 10:1. A capsule states milligrams of extract and the ratio, the figure to set beside the 600 or 1,200 mg a day of the memory trial.¹ A blend or gummy carries tremella alongside five or more species, usually printed as a whole-mushroom equivalent; divide by the ratio to find the extract. No form has been tested against another, and no trial has used a gummy or a blend, so the honest comparison is the labelled milligrams, the species and part named, and a beta-glucan percentage where the maker gives one.

Frequently asked questions

How much snow fungus did the trials use?

600 or 1,200 mg a day of Tremella fuciformis for eight weeks in the memory trial, whose abstract does not describe how the material was prepared, with no difference in adverse events between the two doses; the prediabetes trial used a once-daily beverage for 12 weeks, and its abstract does not state how much tremella the drink contained.^{1, 2}

Can you eat snow fungus every day?

As a cooked food, yes, as East Asian households have for generations. As a supplement, the trials ran eight and 12 weeks; longer daily use is untested, and anyone on a regular medicine checks with a pharmacist first.

Does snow fungus contain collagen?

No. Collagen is made only by animals. Snow fungus holds water because of its polysaccharides, which is a different thing, and no trial has measured what it does to skin.

Is Tremella mesenterica the same thing?

No. Yellow brain is an orange jelly fungus and a different species; its one human study, 52 patients with H. pylori infection, found it did not clear the infection.³

Is snow fungus good for weight loss?

No trial has measured weight as a primary outcome. The prediabetes trial recorded waist circumference falling from 95.2 to 93.5 cm over 12 weeks on a daily tremella beverage, a figure its authors call exploratory.²

Sources

1. Ban S, et al. Efficacy and safety of Tremella fuciformis in individuals with subjective cognitive impairment: a randomized controlled trial. Journal of Medicinal Food, 2018. PubMed 29319408.
2. Gitsomboon S, et al. Tremella fuciformis beverage improves glycated hemoglobin A1c and waist circumference in overweight/obese prediabetic subjects: a randomized controlled trial. BMC Nutrition, 2024. PubMed 38439104.
3. Lachter J, et al. Tremella mesenterica (yellow brain) is subjectively but not objectively effective for eradication of Helicobacter pylori: a prospective controlled trial. Int J Med Mushrooms, 2012. PubMed 22339708.
4. Lin YK, et al. Effectiveness of fish roe, snow fungus, and yeast supplementation for cognitive function: a randomized, double-blind, placebo-controlled clinical trial. Nutrients, 2023. PubMed 37836504.
5. NHS. Herbal medicines and complementary therapies. Page last reviewed 1 May 2026. nhs.uk.
6. MHRA. Yellow Card: report a suspected side effect. yellowcard.mhra.gov.uk.
7. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. gov.uk.
8. Food Standards Agency. Novel foods: regulated products guidance. food.gov.uk.
9. Food Standards Agency. Outcomes on novel food consultations (GB). gov.uk.

This article is general information, not medical advice. Snow fungus has no authorised health claim in Great Britain and has not been tested in pregnancy, breastfeeding or under-18s; anyone with prediabetes or diabetes, on a regular medicine, or with a mushroom allergy should ask a pharmacist or GP before taking it as a supplement.