Yes LDN has many positive effects on the menstrual cycle.
Period pain (dysmenorrhoea) significantly improves. Many women report taking much less pain relief when using LDN.
Pre-menstrual syndrome (PMS) and Pre-Menstrual Dysphoric Disorder (PMDD) dramatically improve in 80% of women and can be life changing.
Women with PCOS may get an earlier ovulation and shorter cycle.
Brown menstrual bleeding can reduce, due to reduced inflammation from LDN, making a healthier cycle and conception more likely.