Chinese researchers have found that electroacupuncture (EA) at Sanyinjiao SP-6 has a specific and immediate beneficial effect on dysmenorrhoea, compared with Xuanzhong GB-39 and an adjacent non-meridian point. Fifty-two women with primary dysmenorrhoea were assigned to one of four treatments: EA at Sanyinjiao SP-6, EA at Xuanzhong GB-39, EA at an adjacent non-meridian point or no acupuncture (waiting list group). They received ten minutes of treatment at a time when their menstrual pain scored ?40 on a 100 mm visual analog scale (VAS), and 30 minutes of treatment on the following two days. The SP6 group showed a highly significant reduction in VAS scores compared with the waiting list group (?23.19 mm), the GB39 group (?18.58 mm) and the non-meridian point group (?20.78 mm). (A Comparative Study on the Immediate Effects of Electroacupuncture at Sanyinjiao (SP6), Xuanzhong (GB39) and a Non-Meridian Point, on Menstrual Pain and Uterine Arterial Blood Flow, in Primary Dysmenorrhea Patients. Pain Med. 2010 Oct; 11(10):1564–75). A related Chinese group has found that needling Sanyinjiao SP-6 can immediately improve uterine arterial blood flow in dysmenorrhoea patients, while Xuanzhong GB-39 does not have this effect. Sixty-six patients with primary dysmenorrhoea were randomised to two interventions. The SP6 group was treated with manual acupuncture at bilateral Sanyinjiao SP-6 for five minutes while experiencing menstrual pain, while the control group was needled at bilateral Xuanzhong GB-39 for five minutes while experiencing menstrual pain. At five minutes after treatment, the SP6 group demonstrated highly significant reductions in menstrual pain scores, uterine artery pulsatility index (PI), uterine artery resistance index (RI), and in the ratio between the systolic peak and diastolic peak (A/B) in the uterine artery. No such changes were observed in the GB39 group. (Immediate Effect of Acupuncture at Sanyinjiao (SP6) and Xuanzhong (GB39) on Uterine Arterial Blood Flow in Primary Dysmenorrhea. J Altern Complement Med. 2010 Oct 9.
Another Chinese group has found that single-point acupuncture was better than no acupuncture for relieving the dysmenorrhoea. However, in this study of 196 women, no significant differences were detected between electro-acupuncture at Sanyinjiao SP-6, acupuncture at Xuanzhong GB-39 and acupuncture at a non-acupoint. (Immediate Analgesia Effect of Single Point Acupuncture in (Primary Dysmenorrhea: A Randomized Controlled Trial. Pain Med. 2010 Dec 17.