— Vitamin B6 : Vitamin B6 is the only ingredient on this list that is synthetically produced. However, B6 is a naturally-occurring compound we get from foods like fish, chicken, and meat, so that’s why this supplement still calls itself “all natural”. When delivered as part of a formula, vitamin B6 has higher bioavailability. It’s also been shown to act as a regulator of androgen production, which is our body’s natural precursor to testosterone. In other words, more vitamin B6 means more androgen, and more androgen means more testosterone.