Excerpted from Bensky:  Chinese Herbal Medicine Materia Medica, 3rd ed.

• Tonifies the blood:  for blood deficiency with such symptoms as facial pallor, dizziness, palpitations, and insomnia.  Very commonly used when blood deficiency leads to such problems as irregular menstruation, uterine bleeding, and postpartum bleeding.  Best when there is deficiency but no significant stagnation.*
• Nourishes the yin:  for Liver and Kidney yin deficiency with such sumptoms as weak lower back and limbs, dizziness, tinnitus, tidal fevers, nightsweats, and nocturnal emissions.*
• Strongly enriches the yin and relieves wasting and thirsting disorder:  especially useful for lower  burner wasting:  can be used as a stand-alone herb in large doses for this purpose.*
• Nourishes the blood and tonifes the essence:  for problems with both blood and essence such as delayed development during childhood, blunted affect, premature aging, diminished mental acuity, greying of hair, impotence, and memory loss.*

Shu Di Huang - Rehmanniae Radix Praeparata