Ironically, O2 does in fact come from trees and plants as the end product of photosynthesis. No prescription needed. No list of potential side effects to discuss with your doctor.
Of course concentrating and compressing the gas to 90% oxygen is a human process, but the substance O2 is perfectly natural. The end result is higher oxygen levels in your system, which is a direct solution to hypoxia due to elevation.
Last edited by SierraNevada; 03/08/12 05:52 AM.
