What are the side effects of Natrum Phosphoricum 3X HPUS?

Simply put, the only side effects from homeopathy are the same as placebo, or water. The system of dilution commonly used in homeopathic remedies results in NO active ingredient being left in the homeopathic 'solution.'

As an example, a homeopathic dilution of 30c would reduce the amount of 'active ingredient' so much that you would need a sphere of water with a diameter of 800 light years to have on molecule of the active ingredient left.