Rehmannia: Benefits, Uses & Dosage

Rehmannia (Rehmannia glutinosa), known in Chinese medicine as Di Huang, is an important tonic and rejuvenative herb for the kidneys and liver. Its rasa is sweet and bitter, virya is cooling, and vipaka is sweet. It pacifies Pitta and Vata but may aggravate Kapha and Ama due to its heavy, nourishing nature. Rehmannia acts on plasma, blood, marrow and nerve, and reproductive tissues, influencing the reproductive, urinary, digestive, and respiratory systems.

The raw form of rehmannia is used for clearing deep-seated fevers and is considered cooling in energy, while the cooked form (Shu Di Huang) is used for most tonic purposes and is considered slightly warming. In Ayurvedic terms, rehmannia is Kapha in nature—it increases bodily tissues, fluids, and secretions. Both forms decrease Pitta and treat Pitta disorders such as anemia. Cooked rehmannia serves as a good substitute for shatavari as a tonic and rejuvenative for the uterus.

Rehmannia's actions include nutritive tonic, rejuvenative, aphrodisiac, demulcent, laxative, and emmenagogue. It is indicated for weak kidneys, low back pain, sexual debility (male or female), irregular menstruation, cirrhosis, anemia, hair loss, diabetes, and senility. The root is primarily prepared as a decoction or powder (250 mg to 1 g). Precautions apply in cases of weak digestion, severe congestion, or edema.