Rhodiola rosea

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

• Studied for Fatigue and perceived stress

  200–680 mg

  Limited

  Standardised root extract · 3% rosavins / 1% salidroside · 4–12 weeks

  Most of the trials used one branded Scandinavian extract. Products standardised only to salidroside, or made from other Rhodiola species, are not the same preparation.

• Studied for Single-dose mental fatigue in shift workers and students

  100–576 mg

  Limited

  Standardised extract, single or short-course dosing · Single dose to 20 days

  Short, small crossover studies with cognitive test batteries that differ between studies, which makes the results difficult to compare.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

• 🌅Morning

  Not enough

  Taken in the morning by convention, because some users report it is activating and disturbs sleep taken late. No trial has compared morning with evening dosing.

  Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

• ⏳On an empty stomach

  Not enough

  Trial protocols often specified dosing before breakfast. Whether food changes absorption of rosavins has not been studied in people.

  Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.