Prepared Magnolia Bark

Traditional Use

Primary Actions

• Moves Qi and relieves focal distention ... Zhi Hou Po is used when fullness, bloating, epigastric oppression, abdominal pain, or food stagnation are driven by middle-burner Qi blockage.
• Dries Dampness and harmonizes the Spleen and Stomach ... it remains a standard choice when damp obstruction leads to poor appetite, nausea, greasy coating, loose stool, or a heavy obstructed digestive sensation.
• Descends rebellious Qi and transforms phlegm ... the prepared bark is used for cough, wheezing, chest congestion, and plum-pit Qi when phlegm and constrained descent bind the chest and throat.
• Promotes downward movement in the intestines ... especially when constipation coexists with distention, pressure, and stubborn Qi stagnation rather than simple dryness.

Secondary Actions

• Compared with raw Hou Pu, the prepared form is generally understood as a little cleaner, more clinically manageable, and somewhat better suited to routine internal prescribing where roughness or excessive aromatic harshness is undesirable.
• Exact local processing methods vary, but the clinical identity remains that of Hou Pu rather than a separate herb ... strong downward movement, dampness transformation, and relief of middle-burner fullness.

Classic Formulas

• Ban Xia Hou Pu Tang (半夏厚朴汤) ... classic Jin Gui Yao Lue formula using Hou Pu for plum-pit Qi, throat obstruction, nausea, and emotional constraint with phlegm.
• Ping Wei San (平胃散) ... dampness-transforming formula in which Hou Pu moves Qi, dries damp, and relieves epigastric and abdominal fullness.
• Hou Pu San Wu Tang (厚朴三物汤) ... abdominal fullness, pain, and constipation driven by pronounced Qi stagnation.
• Ma Zi Ren Wan (麻子仁丸) ... includes Hou Pu to move constrained Qi and help bowel movement when distention accompanies dry constipation.

Classical References

• Classical materia medica consistently describe Hou Pu as bitter, acrid, warm, and aromatic, entering the Spleen and Stomach to move Qi, dry dampness, and direct stagnation downward.
• Formula tradition uses processed and unprocessed Hou Pu in overlapping ways, but the prepared form is commonly preferred when a cleaner and slightly moderated interior use is desired.
• PREPARATION NOTE: Zhi Hou Po is not a distinct species or a different medicinal family ... it is the clinically prepared bark form of Magnolia officinalis used to make the crude bark easier to handle and prescribe.