Oyster Mushroom

Pleurotus ostreatus

Snapshot

Indications	Contraindications
Recurrent respiratory infections^{1, 2} Asthma control in children³ Postprandial glucose⁴ Cardiometabolic markers⁵ Episodic memory in older adults⁶ Herpes labialis duration⁷ Mild atopic dermatitis (topical)⁸	Mushroom allergy⁹ Pregnancy and nursing¹⁰

Oyster mushroom (Pleurotus ostreatus) is an edible fungus used in traditional medicine and as a food, and its beta-glucan fraction, pleuran, acts on immune signaling⁹. Supplementation centers on immune support, particularly prevention of recurrent respiratory infections in children^{1, 2}. Other uses are blood glucose and lipid support and cognition and mood in older adults.

Human research is limited to about sixteen small trials, mostly in pediatric respiratory infections and cardiometabolic markers. A systematic review of fungal beta-glucan trials found fewer respiratory infections and improved allergic symptoms, with inconsistent immune markers¹¹. For lipids the picture is mixed: a review reported lower glucose and lipids but rated the trials at high or unclear risk of bias⁵, while a trial in people with human immunodeficiency virus (HIV) on antiretroviral therapy found no change in non-high-density lipoprotein cholesterol¹². In 2025, a trial in children with partially controlled asthma found pleuran plus vitamin C improved asthma control and respiratory infection frequency in age-specific subgroups³. In 2024, a cell study found a polysaccharide from the mushroom induced apoptosis in a mouse tumor cell line, with no human trial. Products listing oyster mushroom are mostly capsules and tablets, often within multi-mushroom blends; see Form comparison.

Spore inhalation has caused occupational asthma and anaphylaxis⁹. Per United States (US) product labels, many products ask for a physician's advice with medications, and some advise stopping before surgery¹⁰.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

39 sources, 31 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources