Hello, a friend of mine, suffering from arthritis in his right knee, is trying very low doses of cannabis extract in the hope to get rid of the pain. The cannabis extract was made from unknown cannabis plants (from the street) that were dried and then processed the usual way (decarboxylation) with later evaporated ethanol. After the first day of intake he discovered that his urine was dark (reddish) at 2 AM but later at 7 AM, before breakfast, his urine was found normal again. My question: is this an alarming sign? My friend feels fine and had no (perceived) side-effects.