A purified baker's yeast fiber that gently readies the immune system. The most reliable finding is a modest reduction in common colds and other upper-airway infections, with shorter, milder episodes. Benefits are clearest in stressed adults, endurance athletes, and older people. It is safe, inexpensive, and easy to access; effects are genuine but moderate. (Full Review)

Protocol

Standard Dose

250 mg once daily

Single daily dose; taken with a meal such as breakfast

Higher-Dose Option

500–900 mg daily

For symptom severity in frequently infected adults

Duration of Use

4–12 weeks continuous

Through cold-and-flu season or heavy training blocks

Time to effect

Immune Priming

10–14 days

Before priming becomes meaningful

Outcome Window

4–12 weeks

Period over which trials assess effects

Benefits

High: Reduced incidence of upper respiratory tract infections

Medium: Reduced duration and severity of cold and flu symptoms; improved mood and energy under psychological stress; reduced exercise-induced immune suppression

Low: Enhanced antibody response to vaccination; favorable modulation of innate immune markers

Speculative: Trained immunity and broad infection resilience; support for immune aging

Contraindications

Solid-organ transplant recipients or active immunosuppression

Known yeast or glucan allergy

Active autoimmune disease (relative caution)

Pregnancy or breastfeeding (precautionary)

Key Interactions

Immunosuppressant drugs (tacrolimus, cyclosporine, mycophenolate, corticosteroids)

Vaccines (may enhance antibody response)

Risk & Side Effects

High: Mild gastrointestinal symptoms

Medium: Allergic or hypersensitivity reactions

Low: Transient immune-activation symptoms

Speculative: Theoretical aggravation of autoimmune or inflammatory conditions; theoretical interference with immunosuppressive therapy

Monitoring

Marker	Target	Why
hs-CRP	< 1.0 mg/L (ideally < 0.5)	Tracks whether low-grade inflammation shifts over time
White blood cell count with differential	~4.0–5.5 × 10⁹/L	Broad check of immune-cell balance, including neutrophils and lymphocytes
25-OH Vitamin D	40–60 ng/mL	Vitamin D status strongly shapes immune function and can confound benefit
Salivary or serum IgA	Within age-adjusted normal range	Mucosal antibody linked to airway defense that beta-glucan has raised in trials

Cadence: Baseline, again at ~3 months of consistent use, then every 6–12 months

Qualitative Assessment

Frequency and duration of colds and other upper-respiratory infections across a season
Energy and vigor, especially during stressful or high-training periods
Speed of recovery from strenuous exercise or travel
General sense of well-being and mood under stress

Wellmune for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment