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Note: the formulas described here are intended for prescription by health professionals, such as acupuncturists, who are trained in the proper use of Chinese herbs and in the determination of "syndromes" described in the Chinese system of therapy. The listing of indications for formulas does not imply that any of the formulas are effective for alleviating symptoms or disorders; this is simply a description of the Chinese way of presenting herb formulas.

danggui Tang-kuei..................... 8%
baishao Peony.......................... 7%
gouqizi Lycium fruit................... 7%
danshen Salvia.......................... 7%
chaihu Bupleurum..................... 6%
dihuang Rehmannia.................... 6%
chuanxiong Cnidium........................ 6%
yujin Curcuma....................... 6%
zhizi Gardenia....................... 6%
shanzhuyu Cornus......................... 5%
nzhenzi Ligustrum...................... 5%
huangqi Astragalus.................... 5%
niuxi Achyranthes................. 5%
heshouwu Ho-shou-wu................. 5%
baizhu Atractylodes................. 4%
renshen Ginseng....................... 4%
xiangfuzi Cyperus....................... 4%
mudanpi Moutan........................ 4%

Tang-kuei 18 is the designation for a Seven Forests tableted Chinese herb formula. It is named for two things: a key ingredient that indicates-to those knowledgeable about Chinese herbs-the main applications of the formula, and the number of ingredients, a total of 18.

Tang-kuei (also written dang gui, dong kwai) refers to the root of Angelica sinensis, especially known for its blood nourishing properties. The formula is aimed primarily at helping people who experience a "blood deficiency syndrome" as defined in the Chinese system. Although this syndrome has some features in common with the problem of anemia, it is not defined by blood tests (that might indicate, for example, deficiencies of accessible iron or of red blood cells), but by a collection of potential signs and symptoms elaborated in Chinese texts, some of which are centuries old. Persons who display at least some of the indications are thought to benefit by using formulas that include tang-kuei as a key ingredient. Typically, Tang-kuei 18 and similar formulas would be taken over a period of several weeks.

The Chinese system of herbal therapies provides certain insights into the origin and development of the health problems it aims to rectify. It is a common saying of ancient Chinese interpretation that women tend to suffer from blood deficiency. This is understood to be partly the result of monthly menstrual bleeding that would deplete the blood. Modern laboratory analysis shows that women have a lower baseline level of iron and red blood cells than men. Ranges given by different labs will vary, but here are some examples:

Laboratory Measurement Ranges Cited for Males Ranges Cited for Females
Hematocrit 45-62%; 40-54% 37-48%; 37-47%
Hemoglobin 13-18 g/dL; 14-18 g/dL 12-16 g/dL
Red Blood Cell Count 4.3-6.2 million/L; 4.2-5.6 million/L 3.8-5.5 million/L; 3.9-5.2 million/L

Blood deficiency syndrome might also arise from poor diet, from malabsorption of nutrients, or from various defects in metabolism of nutrients. In the Chinese system, such disorders are often described as "weakness of the spleen and deficiency of the liver." Here "spleen" refers to the organ that extracts and distributes nutrients from foods and "liver" refers to the organ that stores blood. The main method for enriching the blood is consuming nutritious foods; additional help may be sought by taking supplements, including iron (see appendix below). But, the Chinese concept of nurturing the blood goes further than this. Some of the indicators Chinese herbalists look for in terms of blood deficiency syndrome include:

  • Dry, thinning, or lusterless hair
  • Pallor, sometimes with patches of skin redness
  • Dry or scaly skin
  • Poor eyesight, blurry vision, dry eyes
  • Dizziness, ringing in the ears
  • Insomnia, especially difficulty falling asleep
  • Nails easily split or malformed
  • Menstrual irregularity
  • Limited flexibility, due to tendon or muscular tightness

In addition, certain other syndromes are thought to have blood deficiency as one component of a more complex pattern, including chronic inflammatory disorders of the skin, chronic hepatitis, and disorders that involve shaking, convulsions, or persistent muscular tension.

Although blood deficiency is more common in women than in men, and although menstrual irregularities are mentioned as one of the potential indicators for use of the blood nourishing formulations, Tang-kuei 18 and similar formulas are not solely indicated for women. Rather, they are useful for men and women, but are more frequently recommended to women.

Tang-kuei 18 may be understood as the combination of key ingredients from several traditional formulations used by Chinese herbalists to alleviate blood deficiency syndromes:

Common Name Chinese Name Ingredients in Common with Tang-kuei 18 Indications for Use
Tang-kuei Four Combination Si Wu Tang tang-kuei, peony, rehmannia, cnidium blood deficiency, irregular menstruation
Bupleurum and Peony Formula Jia Wei Xiao Yao San tang-kuei, peony, bupleurum, gardenia, atractylodes, moutan mental agitation, feverish feeling, irregular menstruation
Ginseng and Tang-kuei Ten Combination Shi Quan Da Bu Tang tang-kuei, peony, rehmannia, cnidium, astragalus, atractylodes, ginseng sallow complexion, weakness, fatigue
Cornus and Rehmannia Formula Ming Mu Di Huang Wan tang-kuei, lycium, bupleurum, rehmannia, cornus, moutan poor eye sight
Cnidium and Tang-kuei Combination Xiong Gui Bu Xue Tang tang-kuei, peony, rehmannia, cnidium, achyranthes, atractylodes blood loss, poor eye sight

Tang-kuei is included in all the above formulas, and peony is in all but one of them; these are the two primary ingredients of Tang-kuei 18. The five reference formulas of traditional Chinese medicine listed above-all of which are used for blood deficiency syndromes-contain ingredients that make up the main part of Tang-kuei 18. A few additional ingredients were included in Tang-kuei 18, as follows:

Common Name Chinese Name Uses in the Chinese herbal system
Salvia danshen vitalizes circulation of blood, nourishes blood
Curcuma yujin vitalizes circulation of blood
Ligustrum nuzhenzi nourishes blood, improves hair
Ho-shou-wu heshouwu nourishes blood, improves hair
Cyperus xiangfu regulates circulation

Tang-kuei 18 has been produced for ITM under the Seven Forests label since 1987. A nearly identical formulation is also produced by Nature's Sunshine Products (called Chinese Blood Build; formerly called BP-C). Since their initial production, about 20 tons of these formulas have been manufactured and distributed. They have been used with apparent safety during this time, and the demand for them has remained strong. The Seven Forests formula is available in bottles of 100 tablets, 250 tablets, and 420 tablets, the latter size suitable for long-term use, as is common practice.

About Getting Enough, But Not Too Much, Iron

Iron is a heavy metal that is essential to life. It has been determined that human adults can usually maintain a healthy level of iron in the blood stream by consuming a total of about 10 mg of iron each day. There are three primary dietary sources for iron (see tables, next page, for examples):

  • consumption of meat, usually providing 1-4 mg in a modest serving of about 3 ounces (currently recommended for a single meal portion to minimize consumption of saturated fats);
  • dried fruits, fruit juices, vegetables, and legumes, usually providing 1-3 mg per serving of about half a cup (these are items that are encouraged to be consumed with higher frequency to assure adequate intake of vitamins, flavonoids, fiber, and other beneficial plant components);
  • wheat products, which are usually made with iron-fortified flour, providing 1-2 mg of iron in two sandwich slices).

Following is a table indicating the iron content of some commonly available iron-rich foods, providing at least 1 mg of iron per serving, and ranked in order of iron content:

Iron-Rich Foods Serving Size Iron (mg)
Oysters 3 ounces 13.2
Beef liver 3 ounces 7.5
Prune juice 1/2 cup 5.2
Clams 2 ounces 4.2
Walnuts 1/2 cup 3.8
Ground beef 3 ounces 3.0
Chickpeas 1/2 cup 3.0
Bran flakes 1/2 cup 2.8
Pork roast 3 ounces 2.7
Cashew nuts 1/2 cup 2.7
Shrimp 3 ounces 2.6
Raisins 1/2 cup 2.6
Sardines 3 ounces 2.5
Spinach 1/2 cup 2.4
Lima beans 1/2 cup 2.3
Kidney beans 1/2 cup 2.2
Turkey, dark meat 3 ounces 2.0
Prunes 1/2 cup 1.9
Roast beef 3 ounces 1.8
Green peas 1/2 cup 1.5
Peanuts 1/2 cup 1.5
Potato 1 1.1
Sweet potato 1/2 cup 1.0
Green beans 1/2 cup 1.0
Egg 1 1.0

Iron content of some common foods rich in iron, divided by heme-iron (animal source, more easily absorbed) and non-heme iron (plant source, less easily absorbed, by a factor of about 10). These are also grouped according to type of source; note the variation in iron content among different varieties of a food type.

Heme-iron Food Source Serving Size Iron (mg)
Beef, corned 3.0 ounces 2.5
Beef, lean ground; 10% fat 3.0 ounces 3.9
Beef, round 3.0 ounces 4.6
Beef, chuck 3.0 ounces 3.2
Beef, flank 3.0 ounces 4.3
Chicken, breast w/out bone 3.0 ounces 0.9
Chicken, leg w/bone 2.0 ounces 0.7
Chicken, liver 3.0 ounces 7.3
Chicken, thigh w/ bone 2.3 ounces 1.2
Fish, cod, broiled 3.0 ounces 0.8
Fish, flounder, baked 3.0 ounces 1.2
Fish, salmon, pink canned 3.0 ounces 0.7
Fish, shrimp, 2 1/2 inch 1.1 ounces 0.5
Fish, tuna, canned in water 3.5 ounces 1.0
Pork, lean ham 3.0 ounces 1.9
Pork, loin chop 3.0 ounces 3.5
Turkey, dark meat 3.0 ounces 2.0
Turkey, white meat 3.0 ounces 1.2

Non-iron Food Source Serving Size Iron (mg)
Almonds, raw 10-12 each 0.7
Beans, baked, canned 1/2 cup 2.0
Beans, kidney 1/2 cup 3.0
Beans, lima 1/2 cup 1.8
Fruit, apricots, dried 10 each 1.7
Fruit, dates 10 each 1.6
Fruit, prune juice 1/2 cup 1.5
Fruit, raisins, not packed 1/4 cup 1.0
Rice, brown 1 cup* 1.0
Rice, white enriched 1 cup* 1.8
Vegetables, broccoli, raw 1 stalk 1.1
Vegetables, peas, frozen 1/2 cup* 1.3
Vegetables, spinach 1/2 cup* 2.0
Wheat, bagel 1 whole 1.5
Wheat, bread, white 2 slices 1.4
Wheat, bread, whole wheat 2 slices 1.7
Wheat, macaroni, enriched 1 cup* 1.9
Wheat, spaghetti, enriched 1 cup* 1.6
*serving size and iron content is for cooked food

In a typical diet of three meals per day, one needs about 3 mg of iron per meal (with 1 mg from snacks), which is easily obtained by most people. Some individuals, particularly women, suffer from low iron levels in the blood as a result of: low dietary intake of foods (e.g., low calorie diets), losses of iron from menstrual bleeding, and problems with iron uptake or distribution to iron carriers or reservoirs. To remedy these problems, iron supplements are usually recommended.

There are potential problems with iron supplements, of which the greatest concern is getting too much iron. Excess intake of iron can have these adverse consequences: cause constipation; impair the uptake of essential trace minerals; contribute to a higher state of oxidative stress (iron is one of nature's most potent oxidants); and may, if consumed in large enough amounts, become acutely toxic, with damaging effects to the liver and kidneys. Children who accidentally consume large amounts of iron are most susceptible to the adverse effects and the single most commonly reported poisoning from supplements is due to children getting into packages of iron supplements (all supplements providing iron are now required to have child-proof caps). Generally, supplement recommendations-even for severe iron-deficiency anemia-are for taking less than 40 mg/day, because at that level people can experience nausea and other immediate reactions. In an attempt to maximize iron supplementation without evident side effects, many suppliers of supplements for prescription by nutritionists provide 27 mg/day, the highest amount that is associated with a low incidence of complaints. Manufacturers also attempt to maximize its absorption of iron by using iron glycinate and by including vitamins (mainly vitamin C and several B vitamins) that enhance the absorption of iron. When taking such supplements, check carefully the amount of iron present and avoid consuming more than 30 mg/day.

Designing supplements that maximize iron dosage while at the same time promoting absorption by using a highly absorbable form may not be ideal because it involves adding as much iron as possible to the system. An alternative approach is to provide a more modest amount of iron within a blood nourishing herb formulation (as depicted in the Chinese herbal system). Blood supplementing therapies are a major focus of Chinese herbal medicine (as described above), where much work has been done both in ancient times and with modern clinical research to improve (normalize) the blood conditions of patients suffering from various forms of deficiency.

The mechanism by which such herb materials might function to enhance either the absorption or utilization of iron or other nutrients is not known. Their contribution of substances that are otherwise low in the average diet (saponins, flavonoids, coumarins, etc.) is likely to be a key factor in the favorable effects observed in studies reported by clinics in China.

Two tablets provide:
Herbs (hot water extracts):
heshouwu Ho-shou-wu........................ 250 mg
danggui Tang-kuei........................... 250 mg
baishao Peony................................ 250 mg
huangqi Astragalus.......................... 250 mg
shudi Rehmannia......................... 250 mg
baizhu Atractylodes....................... 250 mg
shanzhuyu Cornus............................... 250 mg
mugua Chaenomeles...................... 250 mg
Iron and Molybdenum:
percentage of U.S. RDA provided in parentheses
(100) Iron................................... 10 mg
(53) Molybdenum...................... 40 ug

ITM has a supplement for providing small amounts of additional iron in a base of blood nourishing herbs, similar to those found in Tang-kuei 18. This supplement can be used along with Tang-kuei 18 to further nourish the blood. The formula is called Iron Shougui (White Tiger brand). All of the herb ingredients of this formula are found in Tang-kuei 18 except chaenomeles, a sour fruit that is said to nourish blood and relax the tendons.

Although its formulation is consistent with over the counter dietary supplements, Iron Shougui is intended for prescription by health professionals familiar with the use of Chinese herbs. In this manner, people with apparent "blood deficiency" can get a comprehensive evaluation and appropriate therapy that might include these or similar supplements, or other formulations that are better suited to the specific conditions presented to the practitioner.


Salvia and the History of Microcirculation Research in China
Lycium fruit
Ho-shou-wu: What's in an Herb Name?
Atractylodes: Baizhu and Cangzhu
White Peony, Red Peony, and Moutan: Three Chinese Herbs Derived from Paeonia
Gardenia: Key Herb for Dispelling Dampness
The Nature of Ginseng
What's in a Name? Xiao Yao San: Free and Easy Wanderer's Powder


Iron Deficiency Anemia
Treatment of Alopecia with Chinese Herbs

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