Hi.. My aunt and I recently tried Oxy-Powder. And I had the same problem. I took four the first night, but didn't really notice anything the next day. I ended up taking 7 capsules before I really felt it working. (it must be said that I have always suffered from constipation)
My aunt on the other hand, she eats alot of fruits and veggies, so she doesn't have a constipated colon, she only needed 3 capsules to feel the effects. We initially started with 4 for her, but that was too much, we cut it back by one... and she felt better.
I was really confused, because her & I both needed completely different dosages. I ended up calling the Oxypowder company, and they told me that it was normal for the dosages to fluctuate some. They gave me this link to the Colon Cleansing FAQ's section of their website. It may help you, or maybe give them a call. They're pretty knowledgeable about it. Either way... Good Luck! I was pleased with it, hopefully you will be too.
The heart-racing is definitely a very unusual response to Oxy-Powder. It could be a result of toxins that are generated from parasitic or fungal die-off as the result of cleansing and the introduction of oxygen. It would be very unusual, but sometimes people that are susceptible to anxiety have unusual responses to an influx of toxins. Some of the individual ingredients in Oxy-Powder are actually used as supplements in order to maintain heart health. It is important to distinguish whether the heart racing is caused by actually taking the colon cleanser or whether it is only occur during the same period of time.
People can experience palpitations from poor adrenal control, stress, anxiety, medications, poor nutritional status, and a number of other things. It may be a good idea to stop taking it for a few days and then re-starting to see if the palpitations cease and if they begin again. This is a fairly easy way of establishing a reasonable correlation between the product and the symptom. Also, if it is due to die-off, it would not be unusual to feel fatigued, experience joint/muscle aches, have a minor rash, feel "foggy," experience trouble sleeping, or feel nauseated. These describe a few of the other possible symptoms that can be related to detoxification and the elimination of parasites.
Source: OxyPowder Review