I was wondering, many unscented pheromones say "additive" on the description. Does this mean that pheromones can't work unless you have some kind of fragrance on you? I never wear frangrances, and I'd rather have no frangrances on me when I go out, that's just me. Is this OK for pheromones effectiveness?

They'll still work, but won't project nearly as well. Also, some people will be able to smell the BO-funk of the mones themselves, so I recommend at least rubbing on a small amount of cologne or even essential oil to cover the scent.

how about covering oil-based pheromones with cologne? is that possible?

Yeah, that's fine. I just spray it on another, nearby spot.

I think they say that since they are technically sold as perfume additives. I cover them most of the time but have forgotten from time to time. If you are wearing a lot of mones though you are going to want a cover. I always wait until they have dried down before I cover, but that's just me.