How many molecules are we applying in a typical product?

We are used to measuring our mone application in terms of mcg. But how many molecules of that product is contained per application?

Consider Alpha-Androstenol with molecular mass of 274.44 (grams/mole). 

Lets consider 1 mcg application of Anol

1 mcg = 0.000001 grams = (1/274.44) * 0.000001 mole = 3.64378E-09 mole

1 mole of a molecule contains 6.022E+23 molecules, which means that

1 mcg of Anol contains 3.64378E-09 * 6.022E+23 = 2.19429E+15 molecules

That's approximately 2 quadrillion or 2000 trillion (2 followed by 15 zeros) molecules in 1 mcg!!

So lets say you apply 10 mcg, you are basically applying 20 quadrillion of Anol molecules.

Now as you spray the product on your skin, many of these molecules may actually not land on your skin and just dissipate or land on nearby surfaces, so you are not actually carrying the full amount. Plus, the molecules will start diffusing (leaping off your skin in to the air around you) almost right after the application.

Some of these molecules will end up in the nostrils of people around you. If enough molecules enter someone's nostrils, and connect with the glomerular layer of their olfactory bulb, the odor of Anol will get detected and processed.

There are lot of unknowns about how many molecules need to get attached for the signal to be noticed and for a mone reaction to occur but the fact is that we are carrying an enormous number of these molecules on us (added to the quadrillions of mone molecules created naturally by our body). Think about that when you worry if 1 mcg of a pheromone is too low of a dose!