Tang-kuei 18 is the most widely prescribed of all the Seven Forests formulas. It is a fundamental blood nourishing prescription adjusted to deal with the most common accompanying conditions such as stagnation of qi and blood (due to "dryness" of the liver), qi deficiency, and blood heat. The primary blood nourishing component is composed of tang-kuei, peony, cnidium, and rehmannia (the ingredients of Siwu Tang), with lycium fruit, ho-shou-wu, cornus, and ligustrum. To promote circulation of qi and blood, bupleurum, cyperus, curcuma, and achyranthes have been added. To tonify qi and enhance production of blood, astragalus, ginseng, and atractylodes are included. Finally, a small amount of moutan and gardenia are added to help clear heat in the blood that accompanies deficiency syndromes. The resulting formula can be used for pallor, general weakness, menopausal symptoms, spontaneous uterine bleeding, leukorrhea, chronic hepatitis, eczema, and various wind disorders. Tang-kuei Tablets, a blood tonic without the herbs for clearing heat but with warm herbs for nourishing the marrow, can be used for blood deficiency associated with a cold syndrome (e.g., kidney yang deficiency with bone marrow insufficiency). Although many of the indications for formulas based on tang-kuei are specific to women (e.g., menstruation-related disorders), the formulas are also suitable for men. In the treatment of most internal wind syndromes, addition of blood nourishing formulas like this one are an important component of long-term therapy.

Dang Gui (tang-kuei) 8% Bai Shao (peony) 7% Gou Qi Zi (lycium fruit) 7% Dan Shen (salvia) 7% Chai Hu (bupleurum) 6% Di Huang (rehmannia) 6% Chuan Xiong (cnidium) 6% Yu Jin (curcuma) 6% Zhi Zi (gardenia) 6% Shan Zhu Yu (cornus) 5% Nu Zhen Zi (ligustrum) 5% Huang Qi (astragalus) 5% Niu Xi (achyranthes) 5% He Shou Wu (ho-shou-wu) 5% Bai Zhu (atractylodes) 4% Ren Shen (ginseng) 4% Xiang Fu Zi (cyperus) 4% Mu Dan Pi (moutan) 4%