Multiple reuse of needles is a major cause of vein damage, and vein damage and collapse is one reason why people progress to more dangerous injecting sites.

This simple, graphic leaflet shows in print what can't be seen by the eye: just how damaging to soft tissue a needle blunted by re-use can be.

As needle blunting is affected by a number of things, the leaflet doesn't give a number of times that it can be used before it looks like that: it could be after a single attempt to find a vein (if the skin was tough, or the needle vulnerable to metal fatigue) or (as was the case when we did the photography) not until 8 or 10 attempts had been made.

However, the feeling of a blunt needle is well known – hence the choice of the more powerful line 'when a needle feels blunt, this is what it looks like'.