Best Supplements for Improved Immune Function
Ranked by research evidence. Compare 55 supplements across 94 papers from the biomedical literature, with effect direction, evidence strength, and dose range for each.
Top picks by evidence
- Low evidence12 studies
Across 12 studies, all reported beneficial effects on immune function, with effect sizes ranging from small to moderate. The most robust evidence comes from a systematic review (n=1502 participants) showing small beneficial effects, and a small RCT (n=50) in adult atopic dermatitis patients that reached statistical significance. The predominant effect size is small to moderate, and the available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed).
- Low evidence6 studies
Across 5 studies, all 5 reported beneficial effects of Saccharomyces cerevisiae on immune function, with effect sizes ranging from small to moderate. The evidence is predominantly moderate in magnitude but inconsistent in precision, as none of the studies reported statistical significance. Most studies did not specify a dose or duration; populations included humans (general and high-risk groups) as well as various animal species.
- Low evidence4 studies
Across all 4 studies, 4 reported beneficial effects on immune function, with effect sizes mixed between small and moderate. Only 2 studies (one animal trial and one review) reached statistical significance. The evidence includes animal models and review-level data; no original human clinical trials were directly assessed, and no consistent dose or duration was reported.
- LowLactobacillus acidophilus L-92Across 12 studies, all reported beneficial effects on immune function, with effect sizes ranging from small to moderate. The most robust evidence comes from a systematic review (n=1502 participants) showing small beneficial effects, and a small RCT (n=50) in adult atopic dermatitis patients that reached statistical significance. The predominant effect size is small to moderate, and the available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed).12 beneficial12 studies
- LowSaccharomyces cerevisiaeAcross 5 studies, all 5 reported beneficial effects of Saccharomyces cerevisiae on immune function, with effect sizes ranging from small to moderate. The evidence is predominantly moderate in magnitude but inconsistent in precision, as none of the studies reported statistical significance. Most studies did not specify a dose or duration; populations included humans (general and high-risk groups) as well as various animal species.6 beneficial6 studies
- Very lowBifidobacterium plantarumAcross all 5 studies, all (100%) reported beneficial effects on immune function, with effect sizes ranging from small to moderate. The evidence is entirely from review articles, generally discussing probiotics including Bifidobacterium plantarum, rather than from direct interventional trials. No specific dose, form, or duration data were reported in these studies.5 beneficial5 studies
- Very lowLactobacillus salivarius UCC118Across 5 review studies, all 5 reported beneficial effects of Lactobacillus salivarius UCC118 on immune function, with predominantly small effect sizes. Doses, study durations, and specific populations were not consistently reported, limiting the precision of the finding. The evidence is drawn entirely from narrative reviews, with no statistically significant findings or original clinical trials included.5 beneficial5 studies
- LowLactobacillus rhamnosusAcross all 4 studies, 4 reported beneficial effects on immune function, with effect sizes mixed between small and moderate. Only 2 studies (one animal trial and one review) reached statistical significance. The evidence includes animal models and review-level data; no original human clinical trials were directly assessed, and no consistent dose or duration was reported.4 beneficial4 studies
- Very lowBifidobacterium animalis subsp. lactis BB-12Across 4 studies, all reported beneficial effects on immune function, with effect sizes ranging from small to large. The highest-quality evidence (a review with evidence score 3) indicated large effects on resistance to respiratory infections. The evidence base is small and consists entirely of review articles, with limited reporting on specific doses, study durations, and populations.4 beneficial4 studies
- Very lowLactobacillus brevis SBC8803Across 3 studies, all reported small beneficial effects of Lactobacillus brevis SBC8803 on immune function, specifically enhancements in natural killer (NK) cell activity and secretory IgA levels. The evidence base is very small (only 3 studies, all reviews) and no study reported statistical significance or specific dose/duration data. No single population or dose range was consistently studied.3 beneficial3 studies