Bo Gu Dan (驳骨丹; Bó Gǔ Dān; Latin: Gendarussa vulgaris; English: gendarussa herb) in the current pharmacopoeia is the dried aerial parts of Gendarussa vulgaris, an evergreen shrub of the acanthus family, gathered in summer at the flowering stage, usually used raw. It is acrid, bitter, and neutral, enters the Liver and Kidney channels, and its core actions are to disperse stasis and reduce swelling, and to harmonize the sinews and bones. It usually goes into decoctions. The usual amount is 3–10 g. It needs no special handling in a decoction. External use is a suitable amount of the fresh or dried herb pounded and applied.
It is not Xiao Bo Gu. Xiao Bo Gu is warm and acrid, warms and unblocks the collaterals for sinew-bone pain that worsens with cold. Bo Gu Dan is neutral, clears and disperses local stasis, and fits acute injury with red, swollen, hot pain. Pregnancy is a caution. A heat-type acute injury with red hot swelling, or broken infected skin, should not use it on its own.
It is used most often for three patterns:
- Sprains and early injury: red, swollen, painful area with limited movement
- Wind-dampness and long strain: sore stiff sinews and bones
- Local stasis swelling after a fall
Acrid, bitter, and neutral, it is not a daily “sinew-bone loosening” herb to keep increasing. Dispersing when there is no stasis, or long-term use, consumes qi and blood.
When external injury blocks local channels, or wind-dampness and overwork strain the sinews and bones, swelling, pain, and stiffness are common. Bo Gu Dan is acrid, bitter, and neutral. It disperses stasis, reduces swelling, and harmonizes the sinews and bones, which is why it appears in Bo Gu Dan Jie Gu San (Gendarussa Bone-Joining Powder)–type formulas. It disperses more than it holds. Pure liver-kidney deficiency with no stasis, or a heat-type acute injury, gets worse if more is added.
Bo Gu Dan is not a catch-all pain or injury herb. In pregnancy, with a heat-type acute injury, or on broken infected skin, using it alone is a poor match. Raw or fresh, and whether it belongs in a formula, should be decided by a licensed Chinese medicine practitioner after pattern diagnosis.