Sang Zhi

What Is Sang Zhi (Mori Ramulus, Mulberry Twig)?

Sang Zhi is the thin, young branch of the white mulberry tree, Morus alba; its pharmaceutical Latin name is Mori Ramulus. The pinyin name simply means "mulberry branch," and in English it is called mulberry twig or ramulus mori. The mulberry is one of the most versatile plants in Chinese medicine: its leaves, root bark, fruit, and branches each enter the pharmacy as separate herbs with different roles.

Sang Zhi is collected in late spring and early summer, when the new branches are still tender; they are cut into short sections or thin slices and dried. The dried pieces are slender, yellowish-gray, and woody with a light texture and a faint, faintly sweet, leafy aroma. Only the young twigs are used, because the traditional texts hold that the tender branches reach the limbs and their channels, especially the upper limbs.

TCM Properties and Actions

Sang Zhi is neutral, balanced and neither cold nor warm, in nature and slightly bitter in flavor, entering the Liver channel, which in Chinese medicine governs the tendons and smooth flow through the limbs. Its recorded actions are to expel wind-damp and relieve obstruction pain, and to promote flow through the channels and collaterals.

Clinically it is used for wind-damp obstruction pain: aching, heavy, stiff joints and muscles, and it is particularly associated with pain and tightness of the shoulders and arms, including stiff shoulder and elbow discomfort that is worse with damp weather or inactivity. Its neutral nature makes it one of the few wind-damp herbs that can be adjusted with warming or cooling companions for either cold-type or heat-type joint pain. It is also traditionally used for edema of the limbs, particularly swelling of the hands and arms, because it promotes water movement while reaching the extremities. A mild, gentle herb, it is considered suitable for chronic rather than acute patterns and for older or weaker patients who cannot tolerate harsh warming herbs.

Traditional Use and Common Combinations

Classical and modern practice places Sang Zhi in formulas for chronic shoulder and arm pain, paired with stronger wind-damp herbs such as Qiang Huo, notopterygium, and Wei Ling Xian, clematis, for cold-type pain, or with heat-clearing herbs such as Ren Dong Teng, honeysuckle stem, for hot, red, swollen joints. For limb edema it appears with dampness-percolating herbs, and in folk practice a Sang Zhi decoction is sometimes used as a foot or hand soak for cold, aching extremities. Its use for shoulder pain has been studied in modern clinical research, which is why the record notes "studied"; such research remains preliminary and does not establish equivalence with standard care.

These are traditional patterns, not diagnoses. Persistent shoulder pain with weakness, a red hot swollen joint, fever, pain after injury, or swelling with chest symptoms requires medical evaluation rather than self-treatment.

Safety, Contraindications, and Interactions

The source record lists this herb as safe, with no traditional contraindications recorded, reflecting its mild, neutral character and long history of both medicinal and soup-based use. "Safe" in this context means that no prohibition is documented in the traditional source, not that any amount suits every person: people with known allergy to mulberry should avoid it, and very large or prolonged use may occasionally cause mild digestive discomfort. Pregnant or breastfeeding women, young children, and people taking chronic medication should still consult a qualified practitioner before using it medicinally. Stop use if rash, itching, or stomach upset appears.

How TCM Practitioners Use It Today

The source dosage is 9-15 grams. Because of its gentleness, practitioners commonly prescribe it at the higher end of this range in decoctions for chronic limb pain, often as a directing herb toward the arms and shoulders in a larger formula; it is also used in pills, medicinal soups, and external washes. Courses can be longer than with harsh wind-damp herbs, but remain tied to the presenting pattern. This guide is educational and does not replace diagnosis or treatment by a licensed practitioner or physician; persistent or worsening joint pain and swelling should be assessed professionally.

Frequently asked questions

Is Sang Zhi safe during pregnancy?

The source records no contraindication and lists the herb as safe, but medicinal doses during pregnancy should still be discussed with a qualified practitioner who knows the pregnancy. Ordinary small amounts in food soups are far below the medicinal dose.

Can Sang Zhi replace prescription medication?

No. Sang Zhi is a gentle traditional herb used for ache and stiffness patterns of the limbs. It is not a substitute for prescribed medication for arthritis, injury, infection, or cardiovascular disease.

What is the difference between Sang Zhi and Sang Ye?

They come from the same tree, Morus alba, but are different parts with different roles. Sang Zhi is the young woody twig: neutral, slightly bitter, entering the Liver channel, and used to guide wind-damp relief toward the limbs, especially the shoulders and arms. Sang Ye is the leaf, mulberry leaf: cold, sweet and bitter, entering Lung and Liver, and used to drain wind-heat in colds and to clear the eyes and liver heat. The fruit, Sang Shen, and root bark, Sang Bai Pi, are separate herbs again.