I have never personally used OxyPowder, but it looks to be an overpriced supplement, it's main ingredient being magnesium. If you have ever taken a large dosage of magnesium, you would know that it causes you to have a bowel movement.
I wouldn't continue taking it for an extended period of time. It should be a one and done type of thing. I would personally use it if I got backed up on the diet, which happens often on the HCG Diet. Personally I believe the reason some people get constipated on the diet though, is because they aren't eating their vegetables.
Instead of OxyPowder, I would just use MCT oil for cooking and for flavoring vegetables, etc. on the diet. MCT is derived from coconut oil, and is the ONLY oil to cause TEF (Thermic Effect of Food). That means it causes thermogenesis, and MCT is also mostly converted to ketone, which can be beneficial when you are eating low carbs, as it will kickstart you into ketosis.
If it were me, I would do away with the magnesium supplement, unless you really end up needing to poo, really really badly. ;)
Jonathan Colson - HCG Diet Coach
If you purchase HCG at Advance HCG, I will be your coach.