What Actually Works for Immunity?
After 2020, everyone wants to "boost their immune system." The truth: you can't really "boost" it, but you can stop weakening it. Here's what actually helps.
TL;DR
Best evidence: Vitamin D (if deficient), Zinc (for cold duration), Vitamin C (modest prevention). Moderate evidence: Elderberry (may shorten colds). Doesn't work: Immune "boosters," mega-doses of anything, most herbal blends.
Strong Evidence (Fix Deficiencies)
Reduces respiratory infection risk if deficient
Note: Only helps if you're actually low. Get tested.
Shortens cold duration by 1-3 days if taken immediately
Note: Only works if started at first symptoms
May reduce cold duration by 8% in adults
Note: Effect is modest. Food sources often sufficient.
Moderate Evidence
May shorten cold/flu duration
Note: Some evidence, but not overwhelming.
Some strains may reduce cold frequency/duration
Note: L. rhamnosus GG, B. lactis have best evidence.
Doesn't Work / Overhyped
Meta-analyses show inconsistent, minimal benefit
Note: One of the most studied herbs. Results disappointing.
You can't actually "boost" your immune system
Note: Marketing term. An overactive immune system is bad (autoimmunity).
No better than moderate doses, may cause GI issues
Note: More is not better. Your body can only use so much.
Real Talk
"Boosting" your immune system is a marketing term, not a medical concept. Your immune system needs to be balanced, not boosted. What actually helps is not being deficient in key nutrients (D, zinc, C) and not sabotaging your immunity with poor sleep, chronic stress, and bad diet.
What Else Actually Helps
- Sleep. 7-9 hours. Sleep deprivation tanks immunity
- Exercise. moderate exercise improves immune function
- Stress management. chronic stress suppresses immunity
- Wash your hands. most effective intervention
- Avoid smoking/excessive alcohol. both impair immunity
The Bottom Line
Fix deficiencies (vitamin D, zinc). Don't waste money on "immune boosters." Sleep, exercise, and hand hygiene matter more than any supplement.
Related Guides
About this information: Our recommendations draw from peer-reviewed clinical trials, systematic reviews, and the same medical databases your doctor uses. These statements have not been evaluated by the FDA. Supplements are not intended to diagnose, treat, cure, or prevent any disease.
Get Science-Backed Supplement Tips
Weekly insights from 47,000+ clinical trials
No spam. Unsubscribe anytime. We respect your inbox.