Studies have shown that B6 does inhibit prolactin build up to some extent. The results were far inferior to a counter-study done with bromocriptine, but they were still better than placebo. So basically, it does work to some degree. Go with high doses of b-complex because the b vitamins work in conjunction with one another. If you have an imbalance of b-vitamins, it will lead to other unwanted deficiencies.