Rehmannia glutinosa (Shu Di Huang)

Tier 3 — weak evidence · TCM tonic · Kidney Yin · Blood nourishment

A foundational herb in TCM used in formulas for kidney yin deficiency, anaemia, and adrenal exhaustion. Prepared (cooked) rehmannia is warming and nourishing; raw rehmannia is cooling. Contains catalpol and iridoid glycosides with demonstrated anti-inflammatory and neuroprotective effects in animal studies. Limited clinical trial data in humans.

Dose: 9–30 g/day as traditional decoction; 500–1,000 mg/day as standardised extract