Si Wu Tang (四物汤) is the oldest and most copied blood tonic in Chinese herbal medicine. Four roots. One pot. Nearly nine centuries of use. This guide shows you how to make it as a decoction or a slow-simmered soup, what tradition says it does, and what modern lab studies have actually measured.

Quick Answer

What it is: Si Wu Tang ("Four-Substance Decoction") is a classic Traditional Chinese Medicine (TCM) formula of four herbs — Shu Di Huang, Dang Gui, Bai Shao, and Chuan Xiong — used to nourish and move Blood. It first appeared in the Song-dynasty pharmacy manual Tai Ping Hui Min He Ji Ju Fang (1107 CE).
How to make it: Simmer the four dried herbs in about 3 cups (700 mL) of water, reduce to roughly 1 cup, strain, and drink warm. For a meal version, slow-cook the same herbs with chicken or pork for 1.5 to 2 hours.
Traditional use: TCM practitioners use it for "Blood deficiency" patterns — pale complexion, dizziness, scanty or irregular periods, and menstrual cramps. It is most associated with women's health, postpartum recovery, and PMS.
What the science shows: Animal studies link Si Wu Tang to red and white blood cell recovery and bone-marrow gene activity (PMID 16201694). Human trials for period pain are small and mixed; a 2020 meta-analysis called the evidence "low" quality (PMID 32631585).

Medical disclaimer: This article is for education only. It is not medical advice and does not replace a licensed clinician. Chinese herbs can interact with prescription drugs and are not all safe in pregnancy or while breastfeeding. Talk to a doctor or a registered herbalist before taking Si Wu Tang, especially if you are pregnant, nursing, on blood thinners, or managing a chronic condition.

What Is Si Wu Tang and Why Is It Called the "Mother of Blood Formulas"?

Si Wu Tang means "Four-Substance Decoction." Si (四) is four. Wu (物) is substance or thing. Tang (汤) is decoction or soup. So the name is plain: a soup of four things.

Those four things are blood-building roots. In TCM, "Blood" (Xue, 血) is more than the red fluid in your veins. It is the dense, nourishing substance that moistens tissue, anchors the mind, and feeds the menstrual cycle. When Blood runs low — a state called Blood deficiency, or Xue Xu — the classical picture is a pale face, dry skin, brittle nails, dizziness, blurry vision, poor sleep, and light or late periods.

Si Wu Tang is the base formula that almost every other blood tonic is built on. Add Si Jun Zi Tang and you get Ba Zhen Tang, which tonifies both Qi and Blood. Add peach kernel and safflower and you get Tao Hong Si Wu Tang, which moves stagnant Blood harder. Herbalists call Si Wu Tang the "mother" or "ancestor" formula for this reason. You can read more on the parent pattern in our guide to Blood Deficiency: What TCM Recommends.

The formula is old. It is usually traced to the Tai Ping Hui Min He Ji Ju Fang ("Imperial Grace Formulary of the Tai Ping Era"), the official Song-dynasty pharmacy handbook published in 1107 CE, though some sources point to an earlier trauma text by Lin Daoren in the Tang dynasty (Me & Qi, 2024). Either way, it has been in continuous use for roughly 900 years.

Si Wu Tang at a Glance

Attribute	Detail
Chinese name	四物汤 (Sì Wù Tāng)
English name	Four-Substance Decoction
Category	Blood-tonifying formula
First recorded	Tai Ping Hui Min He Ji Ju Fang, 1107 CE
Number of herbs	4
Primary action	Nourish and invigorate Blood
Most common use	Women's health, menstrual support, postpartum
Taste	Sweet, slightly bitter, earthy
Nature	Warm

What Are the Four Ingredients in Si Wu Tang?

The whole formula is just four roots. Each has a job, and the four balance each other: two build Blood, two keep it moving.

The Four Herbs and Their Roles

Herb (Pinyin)	Chinese	Common name	Standard dose	Role in the formula
Shu Di Huang	熟地黄	Prepared rehmannia	12 g	Chief. Deeply nourishes Blood and Liver/Kidney Yin
Dang Gui	当归	Chinese angelica root	9 g	Deputy. Builds Blood and gently moves it
Bai Shao	白芍	White peony root	9 g	Assistant. Nourishes Blood, softens the Liver, eases cramping
Chuan Xiong	川芎	Sichuan lovage rhizome	6 g	Envoy. Invigorates Blood and moves Qi so the tonic does not stagnate

The pairing is the clever part. Shu Di Huang and Bai Shao are rich, building herbs — they add substance. Dang Gui and Chuan Xiong are warm, moving herbs — they circulate. Build too much without moving and you get stagnation. Move too much without building and you drain the patient. Four herbs, two forces, one balance. That logic is why the formula has survived nine centuries of copying.

You can dig deeper into the two lead herbs in our profiles of Dang Gui (Angelica) in Chinese Food Therapy and Rehmannia (Di Huang): 10 Ways to Cook With This Root.

A Note on "Shu" vs "Sheng" Rehmannia

Rehmannia comes two ways. Sheng Di Huang (raw rehmannia) is cold and cooling. Shu Di Huang (prepared, steamed in wine) is warm and richly tonifying. Si Wu Tang uses the prepared form. If your herbs are labeled raw rehmannia, you have the wrong one for a blood tonic. Ask your herb shop for shu di huang.

How Do I Make Si Wu Tang? (Step-by-Step)

There are two ways to make it. The traditional decoction is medicine-strength and made with water only. The soup version (the way most families actually cook it) simmers the herbs with meat into a nourishing meal. Both are below.

Method 1: The Traditional Decoction

This is the strong, water-only version a practitioner would prescribe.

You need:

Item	Amount
Shu Di Huang (prepared rehmannia)	12 g
Dang Gui (angelica root)	9 g
Bai Shao (white peony)	9 g
Chuan Xiong (Sichuan lovage)	6 g
Water	3 cups (about 700 mL)

Steps:

Rinse the herbs quickly under cool water to remove dust.
Place all four in a clay or stainless pot. Avoid aluminum and non-stick.
Add the water. Some traditions soak the herbs 20 to 30 minutes first.
Bring to a boil, then drop to a low simmer.
Simmer 20 to 30 minutes, until the liquid reduces to about 1 cup (200 to 250 mL).
Strain out the herbs. Discard them.
Drink the liquid warm, ideally on a fairly empty stomach.

Most classical instructions split one batch into two servings — morning and evening — or make it once daily (Sacred Lotus, 2024). The taste is earthy and a little bitter. That is normal.

Method 2: The Si Wu Tang Soup (四物鸡汤)

This is the everyday home version — a "four things chicken soup" that turns the formula into a meal. It is gentler and tastes far better.

You need:

Item	Amount
The four herbs (same as above)	1 set
Chicken (thighs or half a small bird) or pork ribs	500 g
Red dates (hong zao), pitted	6 to 8
Goji berries (gou qi zi)	1 tbsp
Fresh ginger	3 slices
Water	6 cups (about 1.4 L)
Salt	to taste, at the end

Steps:

Blanch the meat. Drop the chicken or ribs into boiling water for 1 minute, then drain and rinse. This removes scum for a clean broth.
Combine. Put the blanched meat, the four herbs, red dates, and ginger in a soup pot. Hold the goji for later.
Add water and bring to a boil.
Simmer low for 1.5 to 2 hours, lid on, until the meat is tender and the broth is fragrant.
Add goji berries in the last 10 minutes — they turn bitter if cooked too long.
Salt to taste at the very end. Salt early and the meat toughens.
Serve warm. Eat the meat and drink the broth.

Red dates and goji are not in the original four-herb formula. Cooks add them to soften the bitterness and add their own blood-nourishing reputation. For the deep tradition behind this style of cooking, see our overview of Cantonese Lao Huo Tang (Old Fire Soup) Tradition.

Decoction vs Soup: Which Should I Use?

Factor	Decoction	Soup
Strength	Stronger, medicinal	Milder, food-grade
Cook time	20 to 30 min	1.5 to 2 hours
Taste	Bitter, earthy	Savory, pleasant
Best for	Practitioner-guided treatment	Routine monthly tonic
Added ingredients	Herbs and water only	Meat, dates, goji

If a licensed herbalist gave you a prescription, use the decoction at the dose they set. If you are a healthy adult wanting a gentle monthly tonic, the soup is the friendlier place to start.

What Is Si Wu Tang Used For?

In TCM, Si Wu Tang treats Blood deficiency, with or without Blood stasis. That pattern shows up most in menstruation, pregnancy recovery, and the aftermath of blood loss. Here is how tradition maps it.

Traditional Indications

Traditional use	What it looks like (TCM pattern)
Irregular or scanty periods	Light flow, late or skipped cycles from Blood deficiency
Menstrual cramps (dysmenorrhea)	Cramping pain eased by warmth, dark clots
Postpartum recovery	Rebuilding after the blood loss of childbirth
Pale complexion and dizziness	Classic Blood-deficiency signs
Dry skin, brittle nails, hair thinning	Tissues not "moistened" by Blood
Pre-menstrual support	A "monthly tonic" taken after the period ends

The single most common real-world use is women taking it for a few days after their period to "replenish" what was lost. This is folk practice across China, Taiwan, and the Chinese diaspora. For broader context, see our guide to TCM Food Therapy for Period Pain and Chinese Food Therapy for Women's Health.

A word on framing: these are traditional uses rooted in TCM theory and classical texts, not proven medical treatments. The next section covers what laboratory and clinical research has actually measured — which is a different, narrower set of claims.

Does Si Wu Tang Actually Work? What Does the Research Say?

Here is the honest split. The lab evidence (mostly mice) is interesting and points to real effects on blood cells. The human evidence (mostly for period pain) is thin and mixed. Neither proves the broad traditional claims, and both deserve a careful read.

Animal and Cell Studies

The strongest research is on blood-building, usually in mice made anemic by radiation.

A 2005 study found Si Wu Tang raised peripheral blood cells and boosted gene expression of EPO (erythropoietin, the hormone that signals red-cell production) and G-CSF (which drives white-cell production) in the bone marrow of blood-deficient mice (PMID 16201694).
A 2004 proteomics study reported that the formula reversed changes in 14 bone-marrow proteins in irradiated mice, pointing to effects on how blood cells grow and differentiate (PMID 15575213).
A 2014 study found Si Wu Tang helped recover white blood cell counts and protected the gut lining in gamma-irradiated mice (PMID 25324699).
A 2006 study tested the formula's individual constituents and combination on irradiated mice, supporting the idea that compounds like ferulic acid and paeoniflorin contribute to the blood effect (PMID 16819172).
A 2016 systems-biology paper in Scientific Reports mapped Si Wu Tang's molecular targets and connected them to immune and blood-related pathways, offering a modern lens on the old "tonifies Blood" claim (PMID 27677604).

The catch: these are animal and computational studies. Mouse bone marrow is not a human menstrual cycle. They suggest a plausible mechanism. They do not prove the soup will fix your symptoms.

Human Clinical Trials

The human data centers on primary dysmenorrhea (period pain).

A 2007 randomized, double-blind, placebo-controlled trial in Taipei enrolled 78 young women with primary dysmenorrhea. The result was mixed. Pain dropped in the first follow-up cycle, but by the end of treatment Si Wu Tang showed no statistically significant advantage over placebo for pain intensity (PMID 17710126).
A 2020 systematic review and meta-analysis in Maturitas pooled the trials. It found Si Wu Tang looked favorable versus conventional medicine and may have a better side-effect profile, but rated the overall evidence as low quality due to high risk of bias and small samples. The authors called for larger, better-designed trials (PMID 32631585).

Evidence Summary

Claim	Evidence type	Strength
Supports blood-cell recovery	Mouse / cell studies	Moderate (preclinical only)
Eases primary period pain	Small human RCTs	Weak / mixed
Safer than NSAIDs for cramps	Meta-analysis	Low-quality, suggestive
Treats general "blood deficiency"	Traditional theory	Not clinically tested

Bottom line: the science is encouraging on mechanism and underwhelming on proof. If you take Si Wu Tang, take it as a traditional food-grade tonic with a long safety record in healthy adults — not as a substitute for medical care.

Who Should Not Take Si Wu Tang?

This is the most important section. Si Wu Tang is rich and warm, and a few of its herbs carry real interaction risks.

Safety and Contraindications

Situation	Why it matters
Pregnancy	Chuan Xiong and Dang Gui move Blood; classical texts caution against blood-movers in pregnancy. Avoid unless prescribed by a qualified practitioner.
Breastfeeding	The U.S. LactMed database advises that Dong Quai (Dang Gui) "is best avoided during breast feeding" due to lack of safety data (NCBI LactMed, 2024).
On warfarin or blood thinners	Dang Gui may increase bleeding risk and potentiate warfarin. A known moderate interaction (NCBI LactMed, 2024).
Active heavy bleeding	Blood-moving herbs are wrong for active hemorrhage.
Heavy or early periods (excess heat)	Si Wu Tang is for deficiency, not for heavy flooding cycles.
Cold, loose stools / weak digestion	The rich herbs (especially Shu Di Huang) can feel heavy and worsen bloating or diarrhea.
During a cold or fever	TCM avoids tonifying while an "exterior" illness is active.

If you take a prescription medication — blood thinners above all — talk to your doctor before starting. The Dang Gui–warfarin interaction is well documented and not theoretical. For a fuller treatment of herb risks, see our TCM Herb Safety Guide: Interactions, Dosages, and Side Effects.

When to Stop and See a Doctor

Stop and get medical care if you have very heavy or unusual bleeding, severe pelvic pain, signs of easy bruising or bleeding (especially on a blood thinner), or any allergic reaction. Herbal tonics are not a substitute for a workup of anemia, fibroids, or hormonal disorders.

What Are the Common Variations of Si Wu Tang?

Because Si Wu Tang is the base formula, herbalists modify it constantly. Knowing the main spin-offs helps you understand what your practitioner might prescribe.

Variation	Chinese	What's added	Why
Tao Hong Si Wu Tang	桃红四物汤	Peach kernel + safflower	Stronger Blood-moving for stasis, clots, fixed pain
Ba Zhen Tang	八珍汤	Si Wu Tang + Si Jun Zi Tang	Tonifies both Qi and Blood at once
Shi Quan Da Bu Tang	十全大补汤	Ba Zhen Tang + astragalus + cinnamon	Deep, warming Qi-and-Blood tonic
Sheng Yu Tang	圣愈汤	+ ginseng + astragalus	Blood deficiency with strong fatigue
Jiao Ai Si Wu Tang	胶艾四物汤	+ ass-hide gelatin + mugwort	Bleeding with Blood deficiency

The famous "eight-treasure" soup, Ba Zhen Tang, is the most common upgrade for people who feel both tired (Qi) and depleted (Blood). We cover it in depth in our Ba Zhen Soup Traditional Recipe.

How and When Should I Take Si Wu Tang?

Timing matters in traditional practice, especially for menstrual support.

For menstrual support: The common folk pattern is to take it for 3 to 5 days after your period ends, when the flow has stopped — not during heavy bleeding. This is the "replenish what was lost" approach.
Frequency: As a soup, once or twice a week during the post-period window is typical for a healthy adult. As a prescribed decoction, follow your practitioner's dosing.
Best time of day: Warm, and ideally not on a totally empty stomach if the herbs feel heavy on your digestion.
How long: Treat it as a periodic tonic, not a daily forever-habit. If you feel worse — more bloated, looser stools, headaches — stop and reassess.

Where to buy: get shu di huang (prepared, not raw rehmannia), dang gui, bai shao, and chuan xiong from a reputable Chinese herb shop or pharmacy. Many sell the four pre-portioned as a "Si Wu Tang" packet. Our guide to Where to Buy Chinese Medicinal Herbs for Cooking covers sourcing quality herbs.

Frequently Asked Questions

Is Si Wu Tang only for women? It is most associated with women's health because of its menstrual and postpartum uses, but TCM also prescribes it to men with Blood-deficiency signs — pale complexion, dizziness, poor recovery after blood loss. The formula treats a pattern, not a gender.

Can I take Si Wu Tang every day? Generally no. It is a periodic tonic, usually taken for a few days after the period or in short courses. Daily long-term use of the rich herbs can burden digestion in some people. A licensed herbalist can set a safe schedule if longer use is needed.

Does Si Wu Tang help with hair loss or skin? Tradition links Blood deficiency to dry skin, brittle nails, and hair thinning, so the formula is used for "beauty from within." But there are no solid human trials proving it regrows hair or clears skin. Treat those as traditional claims, not medical facts. See our Chinese Food Therapy for Hair Loss for the wider TCM view.

What does Si Wu Tang taste like? The pure decoction is earthy and a little bitter from the rehmannia, with a warm, slightly sweet undertone from dang gui. The soup version — made with chicken, red dates, and goji — tastes savory and pleasant, much easier to drink.

Is Si Wu Tang safe to take during pregnancy? Avoid it in pregnancy unless a qualified practitioner prescribes it. Two of the herbs, Chuan Xiong and Dang Gui, move Blood, and classical texts caution against blood-moving herbs in pregnancy. Safety data are limited, so the conservative answer is no.

Si Wu Tang (Four-Substance Decoction): The Classic Blood-Nourishing Soup