I have a bottle of APC that I\'ve had for over 2 years. Do phermones become weaker over time? Will my bottle of APC be weaker now?

Also, has anyone tried wearing a whole bunch of pheromone products at once? I have AE, the Edge, PF, and the old bottle of APC? Would wearing them all at once be overkill?

Any answers to these questions would be appreciated. Thanks.