Table 2 The top ten most commonly used single herb for premenstrual syndrome (N = 13,820)

Cyperus rotundus L.

Qi stagnation in liver

2,485

1.38

6.3

18.0

Leonurus heterophyllus Sweet

Blood stasis

2,097

1.33

6.3

15.2

Corydalis yanhusuo W. T. Wang

Qi stagnation and blood stasis

1,573

1.28

6.2

11.4

Salvia miltiorrhiza Bge.

Blood stasis

1,281

1.30

6.4

9.3

Eucommia ulmoides Oliv.

Kidney and liver deficiency

1,023

1.26

6.3

7.4

Scutellaria baicalensis Georgi

Dampness-heat

858

1.30

6.5

6.2

Dipsacus asperoides C. Y. Cheng at T. M. Ai

Blood stasis

644

1.17

6.4

4.7

Cuscuta chinensis Lam., or Cuscuta japonica Choisy

Kidney yang and yin deficiency

639

1.44

6.6

4.6

Pueraria lobata (Willd.) Ohwi or Pueraria thomsonii Benth.

External wind, fluid deficiency

616

1.33

6.4

4.5

Paeonia suffruticosa Andr.

Blood stasis and heat

605

1.43

6.6

4.4