No. Depending on what you wash it may take a couple of washes until you find fibers in the upper corners of your bag. (also see: What causes the breaking of microfibers?). Older apparel has the tendency to lose more fibers. The hotter your water, the more likely you’ll lose fibers. And if you only wash soft fabrics, fewer microfibers will break, etc. Whenever you see fibers, take them out, but you can certainly use the washing bag several times before removing the fibers. Make sure that there are no dark microfibers left in the bag when you wash clothes with lighter colors.
Guppyfriend consumers contacted us because they found very few fibers. This is because the microfibers are extremely tiny and barely visible to the naked eye. And that is part of what the bag does (see also: Who tested the bag and what are the results? ): Due to its soft surface and the structure of the filament, fewer fibers actually break.