Nutgrass Rhizome | Traditional Herbal Medicines

🌿 Nutgrass Rhizome – A TCM Herb for Regulating Qi, Relieving Constraint, and Supporting Menstrual Balance

Nutgrass Rhizome, known in Vietnamese as Hương phụ, is the dried rhizome of Cyperus rotundus L., a familiar herb in TCM. It is traditionally valued for regulating Qi, relieving constraint, supporting menstrual regularity, and easing discomfort associated with Qi stagnation, such as rib-side tightness, indigestion, menstrual cramps, or irregular periods.

Quick information

• Scientific name / Pinyin / Chinese: Rhizoma Cyperi / Xiang Fu / 香附.
• Flavors, Nature – Meridian: Slightly Pungent, slightly Bitter, Neutral – Liver, Spleen, and Triple Burner.
• Main benefits: Supports the smooth movement of Qi, helps reduce distending discomfort, supports digestion, and promotes menstrual balance according to TCM theory.
• Reference dosage: 6–9 g daily, commonly prepared as a decoction.

1. Origin and description

Nutgrass Rhizome is the dried underground rhizome of Cyperus rotundus L., a member of the Cyperaceae family. The plant grows widely in tropical and subtropical regions and is commonly found in fields, open ground, roadsides, and moist areas. The medicinal portion develops below the soil and is commonly known in Vietnam as củ gấu.

The rhizome is usually spindle-shaped and slightly curved. Its outer surface ranges from brown to dark brown and may show longitudinal wrinkles and ring-like nodes. The material is firm, mildly aromatic, and slightly Bitter in taste. After harvesting, fine roots and impurities are removed, and the rhizomes may be boiled, steamed, or dried according to the processing method.

2. Related names of Nutgrass Rhizome

Other names: Hương phụ, Củ gấu, Cỏ gấu, Sa thảo căn, Hương phụ tử, nutgrass, purple nutsedge, nut sedge rhizome.

Scientific name: Rhizoma Cyperi.

Pinyin name: Xiang Fu.

Chinese name: 香附.

In herbal practice, both raw and processed forms are used. One common preparation is vinegar-processed Xiang Fu. When purchasing the herb, it is useful to identify whether the material is raw or processed because the intended traditional use may differ slightly.

3. Flavors, Nature – Meridian

According to the Vietnamese Pharmacopoeia, the herb is slightly Pungent and slightly Bitter in flavor, Neutral in nature, and enters the Liver, Spleen, and Triple Burner Meridians. In TCM theory, the Pungent flavor is associated with moving Qi, while the Bitter quality supports dispersing constraint and directing stagnation.

When Qi becomes stagnant, a person may experience fullness, distension, pressure, or discomfort in the chest, rib area, stomach, or lower abdomen. This herb is often included in formulas intended to promote smoother Qi movement and relieve this type of distending discomfort.

Southern Nutgrass Rhizome slices | Thanh Tam Herbs

4. Benefits of Nutgrass Rhizome in TCM

• Regulates Qi and eases discomfort: Traditionally used when pain, pressure, or distension is associated with Qi stagnation.
• Relieves constraint: Commonly included in formulas that support the free movement of Qi when there is chest or rib-side fullness and emotional constraint.
• Supports menstrual balance: Frequently used in formulas for menstrual cramps, irregular periods, or lower abdominal discomfort related to Qi stagnation.
• Supports digestion: May be considered when poor appetite, bloating, stomach discomfort, or fullness is linked to impaired Qi movement.
• Complements pain-relieving formulas: It may be paired with Blood-moving, Qi-regulating, or warming herbs depending on the TCM pattern.

These benefits belong to TCM practice and do not replace medical diagnosis of abdominal pain, menstrual disorders, digestive disease, or gynecological conditions.

5. How to use and dosage

A reference amount according to the Vietnamese Pharmacopoeia is 6–9 g per day, commonly prepared as a decoction. Some Chinese herbal references use approximately 6–10 g depending on the formula and clinical context. Self-increasing the amount is not recommended.

The raw form is traditionally used more for regulating Qi and relieving constraint. Vinegar-processed material is often selected when the goal is to soothe the Liver, support menstrual regulation, and ease pain. The exact amount should reflect constitution, symptoms, other herbs in the formula, and professional guidance.

6. Indications and contraindications

Indications

In TCM, Nutgrass Rhizome may be referenced for stomach discomfort, poor digestion, chest or rib-side pain, menstrual cramps, and irregular menstruation associated with Qi stagnation. It is usually selected according to overall pattern differentiation rather than a single symptom alone.

Contraindications and precautions

People with Yin deficiency or signs of Blood Heat should not self-use this herb without guidance. Pregnant people, those with abnormal uterine bleeding, heavy or prolonged periods, or anyone being treated for a gynecological condition should consult a doctor or Herb doctor before use.

If abdominal pain is severe, menstrual abnormalities persist, or unexplained bleeding occurs, medical evaluation is recommended rather than relying only on herbal treatment.

Whole Southern Nutgrass Rhizome | Thanh Tam Herbs

7. Reference herbal combinations with Hương phụ

• Qi constraint with chest or rib-side fullness: May be combined with Chai Hu, Chen Pi, Chuan Xiong, or Zhi Ke depending on the pattern.
• Menstrual cramps due to Qi stagnation: May be paired with Dang Gui, Chuan Xiong, Bai Shao, and Yan Hu Suo to support menstrual comfort and circulation.
• Irregular menstruation with cold lower abdominal pain: In an appropriate formula, it may be combined with Ai Ye, Rou Gui, or other warming herbs.
• Bloating and poor appetite: May be combined with Chen Pi, Sha Ren, Mu Xiang, or other Qi-regulating and Spleen-supporting herbs.

These combinations are for traditional reference only. Exact proportions and modifications should follow the individual TCM pattern, constitution, symptoms, medications, and professional advice.

8. Frequently asked questions

• Is Hương phụ the same as củ gấu? Yes. The medicinal part is the rhizome of the plant commonly called củ gấu in Vietnam, after proper cleaning and processing.
• How is vinegar-processed Xiang Fu different from the raw form? In traditional processing theory, vinegar preparation is considered to strengthen the herb’s direction toward the Liver and is often chosen when menstrual regulation and pain relief are important.
• Can women self-use it for menstrual cramps? Long-term self-use is not recommended. Severe pain, heavy bleeding, or unusual symptoms should be medically assessed.
• Can it be taken every day? It should not be treated as an everyday tea. Use should match an appropriate TCM pattern and dosage.
• How do I choose good-quality material? Choose dry, firm rhizomes with a mild aroma, no mold or insect damage, and clear sourcing from a reliable supplier.