If you goto sunbeds, Cover up your stomach when you next go there, The pigment will then not be distributed to that area and will go to other areas exposed to the light

Why do people always think that the area injected is most responsive to the sun?
 
It doesn't work that way.
 
I suppose it's the same reason people think they can lose weight in one area by only exercising that one area. (i.e. thighs, stomach)
 
Weight loss comes from the arms, neck, stomach and thighs if you do stomach crunches.
So what if you do arm curls only? Same result. Fat loss will be comparable to above example.
Any fat loss will be equally distributed throughout the body regardless of the exercise.
 
Long story short is: Inject in stomach, leg, arm, results will be the same. If you're injecting in your stomach and getting darker there, you will also get darker on the stomach if you inject into your leg. It has nothing to do with how the drug was administered, just that the stomach area is more susceptible to UV exposure. Or perhaps your genetics play a factor. In any event, do what the other poster said and cover the area you don't want to get any darker.
 
Problem solved.