Also known as: Baker's yeast beta-glucan, Beta-1,3/1,6-glucan, Saccharomyces cerevisiae glucan
Branded IngredientsGood evidence
A purified beta-glucan from baker's yeast, structurally distinct from mushroom or oat beta-glucans. One of the better-evidenced immune ingredients, with a research base that includes independent work.
Typical dose
250.0–250.0 mg per day
Daily, with or without food
What it is
Wellmune is a purified beta-1,3/1,6-glucan derived from the cell wall of baker's yeast, Saccharomyces cerevisiae.
Beta-glucans are not interchangeable, and this is the point most easily missed. The branching pattern determines which receptors they interact with. Yeast beta-glucans have a 1,3/1,6 structure; oat and barley beta-glucans are 1,3/1,4 and behave as soluble fibre affecting cholesterol instead.
So a yeast beta-glucan and an oat beta-glucan share a name and do entirely different things. Mushroom beta-glucans are closer to yeast in structure but still differ in branching and effect.
How it works
Yeast beta-glucan is taken up by immune cells in the gut lining and transported to immune tissue elsewhere in the body, where fragments are released and bind receptors on neutrophils, the immune cells that respond first to a challenge.
The effect is described as priming rather than stimulating. It does not activate immune cells outright; it appears to make them more responsive when something does arrive.
That distinction matters for anyone worried about over-stimulating an immune system, and it is the more accurate description of what the research shows.
What the evidence shows
The research base is larger than for most branded ingredients, with a number of randomised controlled trials, some conducted by independent academic groups.
Trials in people under physical stress, including marathon runners and those in demanding occupations, have reported reduced days with upper respiratory symptoms and improved measures of wellbeing during heavy training periods.
Trial quality varies and some findings rest on self-reported symptoms rather than objective measures. But for an immune ingredient, where the category is generally poorly evidenced, this is comparatively solid ground.
Dosing
The dose used across essentially all the research is 250 mg daily. Higher doses have not been shown to add anything.
Take daily and consistently. The priming effect depends on ongoing intake rather than being acute, and trials generally ran for several weeks to months.
It is most relevant during periods of heavy training or high stress, which is when the trials found effects. For someone training moderately and sleeping well, there is less for it to do.
At a glance
Common forms
Wellmune WGP, Generic yeast beta-1,3/1,6-glucan, Within immune and greens formulas
Half-life / duration
Effects depend on consistent daily intake over weeks
Timing
Daily, with or without food
Competition status
Permitted — not on the WADA Prohibited List
Category
Branded Ingredients
Safety and side effects
Wellmune has a good safety record across a reasonable body of trials, with few adverse effects reported. It has been assessed as safe for use in food and beverages in several markets.
Being yeast-derived, anyone sensitive to yeast should approach with caution, though the purified glucan contains little yeast protein.
Because it modulates immune activity, speak to your doctor before use if your immune system is being managed or suppressed for any reason.
Who should avoid it
Speak to your doctor before use if your immune system is being managed or suppressed. Take care if sensitive to yeast. Speak to your doctor if you take regular medication. Not established at supplemental doses in pregnancy or breastfeeding.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
