Also known as golden root, rhodiola has been shown in studies to improve cognitive function—particularly under stress—and elevate mood by facilitating production of serotonin. Although there is no research indicating that this is necessary, the traditional way to use this herb is to take it continuously for several weeks or months, then take a break of a couple of weeks before resuming use.

How to take: 200–600 mg of a standardized extract each morning, before you eat; start with the lower amount and take more for a stronger effect. If you experience insomnia, then lower the dosage. As with other adaptogens, rhodiola may take 3–4 weeks of use before you notice an effect.