Gel Packs: How long do they last after opened?

How long do you guys reckon the Pheromone Gel packs would remain potent after being opened under normal

cool conditions?

if i use 1/2 a g/p then i work the other half back down into the pack and it is still out of air contact ( i keep

my used g/ps standing upright in a small jar ) this keeps them free of contamination and they are still effective

many long weeks later when i choose to apply again.

I haven't a clue. However I've

left half used gel packs laying around sealed with only a paper clip and they worked like new a couple weels later.

Just don't take them through airport security...