The amount used should be determined by your age, if you’re on birth control and even bathing habits. There is a great article about this in the Studies & Abstracts section. Copulins: pheromone excerpts from The Science of Sex
If you follow Bunny’s instructions in the stickied thread titled Newbie with a few questions you should see some result. If not, test for your own sweet spot by lowering or raising the amount in one drop increments. The dry down is absolutely necessary if you’re applying it straight or it will stink up again after it is re-wet with perfume.
I’ve seen varying results with it myself, from no acknowledgment to instant erection. What I am sure of is that my husband reacts better if I have worn it for several hours before he is exposed.