Safety Profile
Known Safety Concerns
- High purine content -- contraindicated in gout
- Cross-reactivity in yeast-sensitive or Candida-sensitive individuals
- Chromiun GTF content -- relevant for chromium supplementation calculations
- GI bloating and gas common initially
Contraindications
- High purine content -- contraindicated in gout
- Cross-reactivity in yeast-sensitive or Candida-sensitive individuals
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
Brewers yeast is deactivated Saccharomyces cerevisiae used as a B-vitamin supplement. It is high in nucleic acids which increase uric acid production — contraindicated in gout. High purine content. May cause Candida die-off reactions or cross-react with yeast-sensitive individuals. Contains chromium as chromium GTF.
Biological and Chemical Classification
- Scientific Name
- Saccharomyces cerevisiae (deactivated)
Mechanism of Action
Information not yet available for this ingredient profile.
Clinical Evidence of Effectiveness
Information not yet available for this ingredient profile.
Pharmacokinetics
Information not yet available for this ingredient profile.
Recommended Dosage
Information not yet available for this ingredient profile.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Metabolic
- Evidence consistency: High consistency across studies (100%)
- High purine content -- contraindicated in gout
- Cross-reactivity in yeast-sensitive or Candida-sensitive individuals
- Chromiun GTF content -- relevant for chromium supplementation calculations
- GI bloating and gas common initially
The available scientific evidence for Brewers Yeast indicates notable safety signals that warrant caution. Use should be considered carefully and monitored, particularly in sensitive populations or alongside other medications.
Total SETI Score
High risk| Evidence quality | 10/40 |
| Evidence consistency | 20/20 |
| Safety signals | 0/20 |
| Study recency | 9/10 |
| Evidence transparency | 9/10 |
Evidence Summary
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or systematic review)
- 0 studies identified benefits or no safety concern (GREEN)
- 10 studies reported limited or advisory safety evidence (YELLOW)
Evidence Policy
Only peer-reviewed scientific literature indexed in PubMed or comparable databases is included in this evaluation. Commercial websites, blogs, and marketing materials are excluded. All references include direct traceable links to source documents.
Last updated: 25 მარ 2026, 17:57
Evidence Distribution
-
Observational / other LOW evidence YELLOWIn Vitro Fermentation Characteristics of Dietary Fibers Using Fecal Inoculum from Dogs Consuming a Dried Brewers Yeast Product. ↗De La Guardia Hidrogo VM et al.. In Vitro Fermentation Characteristics of Dietary Fibers Using Fecal Inoculum from Dogs Consuming a Dried Brewers Yeast Product.. Animals (Basel). 2025. PMID:41227448.PMID 41227448 ↗Journal Animals (Basel)Year 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41227448/
-
Observational / other LOW evidence YELLOWThe effects of supplemental brewers yeast on postprandial amino acid concentrations in healthy adult sled dogs. ↗Rummell LM et al.. The effects of supplemental brewers yeast on postprandial amino acid concentrations in healthy adult sled dogs.. J Anim Sci. 2025. PMID:40411482.PMID 40411482 ↗Journal J Anim SciYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40411482/
-
Observational / other LOW evidence YELLOWBrewers' Yeast (Saccharomyces cerevisiae) Purified Functional Feed Additives Mitigate Soybean Meal-Induced Enteritis in Atlantic Salmon (Salmo salar) Parr. ↗Momoh TA et al.. Brewers' Yeast (Saccharomyces cerevisiae) Purified Functional Feed Additives Mitigate Soybean Meal-Induced Enteritis in Atlantic Salmon (Salmo salar) Parr.. Aquac Nutr. 2025. PMID:40255579.PMID 40255579 ↗Journal Aquac NutrYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40255579/
-
Observational / other LOW evidence YELLOWBiovalorisation of agro-industrial wastes into astaxanthin by Xanthophyllomyces dendrorhous. ↗Kanwugu ON et al.. Biovalorisation of agro-industrial wastes into astaxanthin by Xanthophyllomyces dendrorhous.. Appl Microbiol Biotechnol. 2024. PMID:39066896.PMID 39066896 ↗Journal Appl Microbiol BiotechnolYear 2024Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/39066896/
-
Observational / other LOW evidence YELLOWLive-cell analysis of IMPDH protein levels during yeast colony growth provides insights into the regulation of GTP synthesis. ↗Shand EL et al.. Live-cell analysis of IMPDH protein levels during yeast colony growth provides insights into the regulation of GTP synthesis.. mBio. 2024. PMID:38940616.PMID 38940616 ↗Journal mBioYear 2024Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/38940616/
-
Observational / other LOW evidence YELLOWUnderstanding the influence of genotype and temperature on proteolytic activity in distinct barley genotypes. ↗Rani H et al.. Understanding the influence of genotype and temperature on proteolytic activity in distinct barley genotypes.. J Food Sci. 2023. PMID:36855307.PMID 36855307 ↗Journal J Food SciYear 2023Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/36855307/
-
Observational / other LOW evidence YELLOWPopulation growth of phosphine resistant and susceptible populations of Lasioderma serricorne (F.) (Coleoptera:Anobiidae) exposed to different temperatures and commodities. ↗Sakka MK et al.. Population growth of phosphine resistant and susceptible populations of Lasioderma serricorne (F.) (Coleoptera:Anobiidae) exposed to different temperatures and commodities.. Environ Sci Pollut Res Int. 2023. PMID:36853531.PMID 36853531 ↗Journal Environ Sci Pollut Res IntYear 2023Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/36853531/
-
Observational / other LOW evidence YELLOWEffect of yeast and essential oil-enriched diets on critical determinants of health and immune function in Africanized Apis mellifera. ↗Canchu00e9-Collu00ed C et al.. Effect of yeast and essential oil-enriched diets on critical determinants of health and immune function in Africanized Apis mellifera.. PeerJ. 2021. PMID:34721958.PMID 34721958 ↗Journal PeerJYear 2021Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/34721958/
-
Observational / other LOW evidence YELLOWBrewers' spent grain liquor as a feedstock for lactate production with Lactobacillusu00a0delbrueckii subsp. lactis. ↗Akermann A et al.. Brewers' spent grain liquor as a feedstock for lactate production with Lactobacillusu00a0delbrueckii subsp. lactis.. Eng Life Sci. 2020. PMID:32874180.PMID 32874180 ↗Journal Eng Life SciYear 2020Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/32874180/
-
Observational / other LOW evidence YELLOWBrewer's Yeast. ↗Brewer's Yeast.. 2006. PMID:34292694.PMID 34292694 ↗Year 2006Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/34292694/
Score Transparency
0 of 10 approved references (score saturates at 10). More peer-reviewed studies = stronger evidence base.
Method: Q = number of approved references ÷ 10 (capped at 1.0)
Limited — mostly case reports or animal studies
Method: L = mean study-level weight across approved references. Level 1 (meta-analysis / systematic review) = 1.0; Level 2 (RCT) = 0.8; Level 3 (cohort/case-control) = 0.6; Level 4 (case report) = 0.4; Level 5 (animal / in-vitro) = 0.2.
Mixed or neutral — roughly equal benefit and risk signals
Method: D = (sum of risk-scored references − sum of benefit-scored references) ÷ total evidence score, then scaled from [−1, 1] to [0, 1]. 0.0 = pure benefit; 0.5 = neutral; 1.0 = pure risk.
One or more monitoring-level safety signals active
Method: S = 0.5 (neutral baseline) + sum of active signal severity deltas ÷ 10. Severity deltas: Critical = +2.0, High = +1.5, Moderate = +1.0, Low = +0.5. Capped at 1.0.
Final GIRI Score for Brewers Yeast. Risk level thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
Full methodology & data sources
The GIRI Score is computed entirely from structured data — no editorial scoring or subjective weighting is applied at any step.
- References: Only approved references are counted. Each reference is assigned an evidence level (L1–L5) and a direction (risk / neutral / benefit) by the reference manager or AI classifier.
- Safety Signals: Sourced from regulatory agencies (FDA, EMA, Health Canada, TGA, and others) and pharmacovigilance databases. Only active signals count toward the score.
- Formula version: GIRI Score v3.7.0 — Q × L × D × S × 10.
- Limitations: The score reflects published evidence and recorded signals as of the last update date. It is not a clinical risk assessment and should not replace advice from a qualified healthcare professional.
Risk Level Classification
Based on available regulatory signals and scientific evidence, this ingredient presents a low safety concern under normal conditions of use.
0–3.0
3.0–5.5
5.5–7.5
7.5–10
The score pin shows exactly where this ingredient falls on the fixed risk scale.
What drove the Low classification for Brewers Yeast
A score of 3.5 places this ingredient in the Low band. Thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
0 approved references.
Limited — mostly case reports or animal studies (Level 4–5).
Neutral or mixed — benefit and risk signals roughly balanced.
No active signals — S component is at neutral baseline (0.5), contributing no extra risk weight.
No major regulatory restrictions or advisories recorded across monitored jurisdictions (FDA, EMA, Health Canada, TGA, and others).
How are the Low / Moderate / High / Critical thresholds defined?
The four risk levels are fixed score bands. A score is assigned to exactly one level based on where it falls:
| Level | Score | Meaning |
|---|---|---|
| LOW | 0.0 – 2.9 | Sparse or predominantly beneficial evidence. No active safety alerts. |
| MODERATE | 3.0 – 5.4 | Mixed signals — some risk alongside benefit. Caution at high doses or in sensitive groups. |
| HIGH | 5.5 – 7.4 | Multiple studies or regulatory alerts documenting adverse effects. Professional oversight recommended. |
| CRITICAL | 7.5 – 10 | Regulatory restrictions in one or more major jurisdictions. Serious documented harm. Avoid without specialist supervision. |
Thresholds are fixed constants (GIRI_Score_Utils::LEVEL_THRESHOLDS). They do not change per ingredient and are never subject to editorial adjustment.