Snake Oil Supplements – analysis

We’ve updated our Snake Oil Supplements? interactive with the latest scientific evidence for the health benefits of the 180 most popular nutritional supps.

The data has been revised top to bottom and draws upon many new Cochrane metastudies of the area.

(Cochrane are the gold-standard of medical meta-studies – studies of studies. They minimise bias by subjecting all existing studies to very rigorous methodological and statistical analysis).

» See the interactive

our analysis


» Melatonin for insomnia – what travellers already knew is now proven (study)
» Dark chocolate for blood pressure – small blood pressure drop (study)
» Olive Leaf extract for blood pressure – evidence it’s good for heart (study)
» Rhodiola rosea L for fatigue – may alleviate tiredness, more research required (study)
» Vitamin K2 for heart disease – may prevent heart calcification (study)
» Eggshell membrane for arthritis pain – works fast at 500mg per day (study)
» Garlic for high cholesterol – 600mg a day brings it down (study)
» Vitamin D for flu, bones, and long life – good evidence for this all-rounder (study)


» Devil’s Claw for lower back pain– low evidence that it reduces pain (study)
» Zinc for colds – reduces duration of cold at dose of ≥ 75 mg/day (study)


» Probiotics for IBS – evidence drops from strong to conflicting (study)
» Valerian for anxiety – massive drop to only slight evidence (study)
» Cranberry juice for urinary infections – zero evidence for cystitis (study)
» Green tea for lowering cholesterol – evidence was strong, now slim (study)
» Fish Oil for heart disease – the “miracle oil” continues its decline (study)


Thanks to visitor suggestions we’ve added a new category for supplements that may be harmful.

» Antioxidants linked to higher mortality – with no evidence of health benefits (study)
» Vitamin A linked to birth defects – safe as a skin cream, though (study)