Best Supplements for Improved Immune Function
Ranked by research evidence. Compare 59 supplements across 99 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, with effect sizes ranging from small to moderate; the predominant effect size is small. The most robust evidence comes from a systematic review (n=1502) and a small randomized controlled trial (n=50) in adult atopic dermatitis patients using heat-killed and dried L-92 daily, which showed a statistically significant small beneficial effect on immune function. Study durations were not consistently reported, and no clear dose range emerges from the available data.
- Low evidence6 studies
Across 5 studies, all reported beneficial effects of Saccharomyces cerevisiae on immune function, with effect sizes ranging from small to moderate. The strongest evidence comes from a systematic review (n=640) showing small beneficial effects and a clinical trial in chicks (n=216) showing moderate benefits. No consistent dose, form, or study duration data were reported across studies, and populations studied varied widely (humans, chicks, animals, in vitro).
- Low evidence5 studies
Across 5 review studies, all reported beneficial effects of Bifidobacterium plantarum on immune function, with predominant effect sizes ranging from small to moderate. No studies provided specific doses, durations, or statistical significance, and the evidence is entirely derived from animal or in vitro research, not human trials. The most commonly cited mechanisms include enhancement of antioxidant enzymes, immune cell maturation, and secretory IgA production.
- LowLactobacillus acidophilus L-92Across 12 studies, all reported beneficial effects, with effect sizes ranging from small to moderate; the predominant effect size is small. The most robust evidence comes from a systematic review (n=1502) and a small randomized controlled trial (n=50) in adult atopic dermatitis patients using heat-killed and dried L-92 daily, which showed a statistically significant small beneficial effect on immune function. Study durations were not consistently reported, and no clear dose range emerges from the available data.12 beneficial12 studies
- LowSaccharomyces cerevisiaeAcross 5 studies, all reported beneficial effects of Saccharomyces cerevisiae on immune function, with effect sizes ranging from small to moderate. The strongest evidence comes from a systematic review (n=640) showing small beneficial effects and a clinical trial in chicks (n=216) showing moderate benefits. No consistent dose, form, or study duration data were reported across studies, and populations studied varied widely (humans, chicks, animals, in vitro).6 beneficial6 studies
- LowBifidobacterium plantarumAcross 5 review studies, all reported beneficial effects of Bifidobacterium plantarum on immune function, with predominant effect sizes ranging from small to moderate. No studies provided specific doses, durations, or statistical significance, and the evidence is entirely derived from animal or in vitro research, not human trials. The most commonly cited mechanisms include enhancement of antioxidant enzymes, immune cell maturation, and secretory IgA production.5 beneficial5 studies
- Very lowLactobacillus salivarius UCC118Across 5 studies (all reviews), all reported beneficial effects of Lactobacillus salivarius UCC118 on immune function, though effect sizes were predominantly small (3 small, 1 moderate, 1 small). No study reported doses, durations, or statistical significance. The evidence is limited to mechanistic and general probiotic reviews rather than dedicated clinical trials.5 beneficial5 studies
- LowLactobacillus rhamnosusAcross 4 studies, all reported beneficial effects of Lactobacillus rhamnosus on improved immune function, with effect sizes ranging from small to moderate. Two studies reached statistical significance. Evidence is drawn primarily from animal models (lambs, mice) and general reviews in healthy adults; no consistent dose or duration was reported across studies.4 beneficial4 studies
- Very lowBifidobacterium animalis subsp. lactis BB-12Across 4 review studies, all 4 reported beneficial effects of Bifidobacterium animalis subsp. lactis BB-12 on immune function, with effect sizes ranging from small to large (predominantly small to moderate). The most robust evidence comes from one high-quality review citing increased resistance to common respiratory infections. No consistent dose range was reported, and study durations were not specified.4 beneficial4 studies
- Very lowLactobacillus brevis SBC8803Across 3 review studies, all reported beneficial but small effects of Lactobacillus brevis SBC8803 on immune function, including enhanced natural killer cell activity and increased secretory IgA levels. No statistically significant findings were reported, and study durations, doses, and forms were not consistently documented. The evidence base is limited to reviews, with no original clinical trials available for this specific strain-outcome pair.3 beneficial3 studies