Provided that Fibro-Vein is injected correctly at the appropriate concentration then ulceration should never happen.

Ulceration or necrosis occur when some of the product is injected outside the vein. The tissue cells die leading to a small area of necrosis which may erupt to the surface as a small ulcer.

Necrosis used to be more of a problem many years ago when too high a concentration was being used to treat thread veins. Some people were using 1% and 3% STS which will cause tissue necrosis.

0.1-0.2% Fibro-Vein is recommended for thread veins and at this concentration it is unlikely to cause necrosis even if injected outside the vein.