1.For PMS sypmtoms take Evening Primrose oil daily.
2.If you believe that you are deficient in vitamin B, you can supplement that as well.
3.As far as I know Chasteberry (Vitex) is the best herb for PMS, with no side effects. Black Cohosh is used for PMS, but it can cause weight gain in the long run, and hence it is not safe to use it for a long time. Dong Quai is also a herb beneficial to PMS, but it can make the skin sensitive to sunlight. That's why I consider Chasteberry to be the safest one among the three herbs. When using chasteberry take it daily when you are not menstruating. Some recommend to start taking Chasteberry extract 2 weeks before the menstruation starts, and stop taking it once it begins.