Q
Which supplements actually work?
⚡ Quick answer
Vitamin D, omega-3, magnesium, creatine, and probiotics have the strongest evidence.
Most supplements are unnecessary or worse than useless. But a few have strong, replicated evidence:
Tier 1 — strong evidence for most adults:
- Vitamin D3 (1000-2000 IU daily): widespread deficiency, supports immunity, bones, mood
- Omega-3 (1-2g EPA+DHA): reduces inflammation, supports brain and heart
- Magnesium glycinate (300-400mg): most people deficient, helps sleep, anxiety, cramps
Tier 2 — strong evidence for specific situations:
- Creatine monohydrate (5g daily): muscle, strength, brain function — most evidence-based supplement ever
- Probiotics: after antibiotics, for IBS, specific strains for specific conditions
- B12 (vegans, elderly, PPI users): non-negotiable for at-risk groups
- Zinc (15-30mg): for acne, immunity, taste
- Iron (only if deficient): test ferritin first
Tier 3 — emerging evidence, optional:
- Berberine: blood sugar control
- Curcumin (with bioavailability enhancer): anti-inflammatory
- L-theanine: calm focus
What to avoid: most multivitamins (low-quality), megadose vitamin C, antioxidant cocktails, weight-loss supplements (mostly scams), testosterone boosters.
Key rule: test before supplementing where possible. Get blood tests for Vitamin D, B12, ferritin, zinc — supplement based on actual deficiency, not guessing.
Read our full evidence-based guide on supplements for the complete picture.
View Full Guide →We write from peer-reviewed research and clinical guidance. These links let you read the underlying evidence yourself rather than taking our word for it.