I had a recurrence of breast cancer last year and took IP-6 and Inositol during and after chemo.
Chemotherapy certainly has a cummulative effect on the body. You become increasingly tired between chemo treatments, as your body has less fight, as your T-cells are killed, in addition to the cancer cells.
I noticed within a few days that my energy returned. I was able to bounce-back faster. I was also very concerned that my white blood count would become too low and chemo would have to be delayed. It's critical that you receive your chemo treatments on time, or cancer has a better chance to return. With IP-6 and Inositol, I made it through all of my treatments on time. I have continued to take it, even a year later, because it has been shown to boost your natural killer cell activity. It is a natural product and will not interfere with his chemo treatments.
You've made a good choice. I wish you both well.