Kampo therapy for premenstrual syndrome: Efficacy of Kamishoyosan quantified using the second derivative of the fingertip photoplethysmogram

Abstract Aim: Premenstrual syndrome (PMS) affects 40–80% of women. Japanese herbal medicine, known as Kampo, is frequently prescribed for PMS, so we examined the efficacy of Kamishoyosan using two methods: first, the second derivative of the fingertip photoplethysmogram (SDPTG) evaluating vascular age (VA), and second, a self‐assessment questionnaire on subjective symptoms. Methods: The SDPTG was recorded in 45 patients with PMS (mean ± SD = 32 ± 6 years of age) before (0 M), on the first (1 M) and third (3 M) month of therapy. Patients answered a questionnaire (44 questions) on their complaints every month. The reproducibility of the SDPTG was confirmed with 15 normal volunteers (33 ± 9 years of age). Results: In patients with older VA than their chronological age (Age) before therapy, we found linear correlations of the VA–Age differences at 1 M versus 0 M ( y = 0.45 x + 1.59, standard error of estimate [SEE] = 6.13 years), and at 3 M versus 0 M ( y = 0.18 x + 4.09, SEE = 6.03 years). The VA–Age decreased from 11.3 ± 6.4 (0 M) to 6.6 ± 6.7 (1 M) and 6.1 ± 6.0 years (3 M) ( P < 0.01). The score on the self‐assessment questionnaires for the five most frequent symptoms significantly improved from 13.4 ± 3.3 (0 M) of 20 to 10.7 ± 3.9 (1 M) and 8.2 ± 4.6 (3 M) ( P < 0.01). Conclusion: The improvement of PMS symptoms as a result of using Kamishoyosan was quantified by means of SDPTG and the self‐assessment questionnaire.