Supplements, herbs, teas and training, graded by evidence
What does science actually say about supplements, herbs and training?
We grade 999 vitamins, supplements, herbal medicines and teas, and 133 training topics, against published clinical trials, meta-analyses and systematic reviews. Each page gives the level of evidence, the studied dose or how to apply it, safety, and the references so you can check the source yourself.
What you will find here
Best supplements by goal
The 27 with strong evidence
Algae Omega-3 (Vegan DHA/EPA)
Algal oil is a genuine plant-based source of preformed DHA (and increasingly EPA) that raises blood omega-3 levels as effectively as fish.
AREDS2 Eye Formula
One of the few supplement formulas with a large, government-funded RCT behind it — but only for a specific population: people who already have intermediate age-related macular degeneration, or advanced AMD in one eye.
Barley Beta-Glucan
The soluble fibre from barley, one of the few supplement ingredients with an authorised cholesterol-lowering health claim.
Caffeine
The world's most widely consumed stimulant.
Casein Protein
Casein is a complete, slowly digested milk protein that builds muscle about as well as any other high-quality protein when it fills a gap in daily intake.
Creatine (monohydrate)
One of the most studied supplements in the world.
Energy Gels
Concentrated carbohydrate in a portable sachet.
Ferrous Sulfate
The reference treatment for iron-deficiency anemia: cheap, effective and extensively studied.
Folic Acid (Vitamin B9)
Periconceptional folic acid is one of the few supplements with an unambiguous, large, replicated benefit: it prevents neural tube defects.
See all 27 → · All 999 supplements, strongest evidence first →
Training, graded by evidence
Comparison guides
Browse by category
- Physical performance supplements: what the evidence says (93)
- General health supplements: what the evidence says (102)
- Sleep and relaxation supplements: what the evidence says (42)
- Stress and mood supplements: what the evidence says (36)
- Immune support supplements: what the evidence says (84)
- Gut health supplements: what the evidence says (124)
- Joint and skin supplements: what the evidence says (74)
- Vitamin and mineral supplements: what the evidence says (62)
- Longevity and antioxidant supplements: the evidence (57)
- Brain and cognition supplements: what the evidence says (53)
- Heart and metabolic supplements: what the evidence says (121)
- Women's health supplements: what the evidence says (56)
- Men's health supplements: what the evidence says (35)
- Weight loss supplements: what the evidence says (45)
- Eye health supplements: what the evidence says (15)
- Herbal medicines: what the evidence says (335)