Supplements: evidence

Graded by evidence level: A — works, B — by indication/deficiency, C — useless or overpaying

A Strong evidence — works for mostB Works by indication or deficiencyC Weak/zero evidence — overpaying
A

Creatine monohydrate

Most studied supplement: +5–15% strength and mass. 3–5 g/day, loading optional.

A

Vitamin D3

Most people are deficient: 1000–4000 IU/day per 25(OH)D test. Immunity, bones, mood.

A

Omega-3 (EPA/DHA)

Heart and inflammation: 1–2 g EPA+DHA/day. Check EPA+DHA content, not 'fish oil'.

A

Whey protein

It's food, not 'chemistry': convenient protein top-up. 20–40 g per serving.

B

Magnesium

For deficiency — cramps, sleep. Citrate/glycinate 200–400 mg in the evening.

A

Caffeine

Working ergogenic: 3–6 mg/kg pre-workout. Tolerance builds.

B

Collagen

Moderate data for joints/skin: 10–15 g + vitamin C. Not a miracle, but harmless.

B

Iron

Only by blood test (ferritin)! Excess is toxic; women need it more often.

C

BCAA

Useless with adequate dietary protein — protein already contains BCAAs.

C

Fat burners

Effect is caffeine and placebo; fat is burned by caloric deficit, not pills.

C

Mass gainer

Sugar + protein; food + protein is better. Only if you can't eat enough calories.

C

Testosterone boosters

Clinically don't raise testosterone in healthy people — money wasted.

Supplements don't replace diet, sleep and training. Before iron, D3, B12 — get tested: excess is worse than deficiency.