It turns out olfactory receptors are present in nearly every human tissue. This article makes the case that a lot of their function is part of a feedback loop with the microbiome.
The article mentions short-chain aromatic fatty acids specifically (which we have experimented with as copulins), and we also know that bacteria convert our hormones into aromatic steroids (at least on the skin.) It could very well be that we are delving into a process that affects not just the olfactory-hypothalamic system, but every system within the body. This could particularly explain some of the profound and lasting self-effects that pheromone users experience as we introduce artificial feedback into the body's generalized chemosensory facilities.
Amen. It's interesting that we test vision, but not smell. Wouldn't it be a cheap and easy test if we could identify a malformed receptor because someone couldn't smell a particular scent?
Of course, rapid genomic testing will probably make this a moot point soon. I suppose I'm just lamenting missed opportunities.