Try taking large doses (1 to 2 tablespoons) of a really good quality echinacea.
Echinacea boosts the immune system, and helps the body get the toxins out. When you are having a "healing crisis" or detoxification headache, your immune system isn't keeping up. Echinacea can really help. A while back the superfood was giving me a cleansing headache everytime I took it. Each time I got the headache, I started to take larges doses of echinacea, and the headache went away in minutes. It could take longer though. I would take a large dose each night of the cleanse.