How it forms
Certain Aquilaria trees, attacked by a fungus, produce a dark resin in defence. That resin saturating the wood is oud, or agarwood.
A healthy tree produces none. The process takes years, and only a minority of infected trees yield resin of quality. That is the whole explanation for the price.
What it smells like
Animal, leathery, smoky, with notes of honey, wet hide, sometimes barnyard or cheese depending on provenance. Nothing like the sweet, clean "oud" of Western fragrance.
Origins differ considerably: Cambodia gives softer, woodier profiles, Assam more animal ones, Borneo greener notes.
What is actually in most bottles
Almost never real oud. Mainstream fragrances use synthetic reconstructions — clean, woody, slightly medicinal — that give the idea without the price or the discomfort. That is not deception: at true cost the fragrance would be unsellable.
Aquilaria is listed under CITES, the convention on trade in endangered species. Wild harvesting is regulated, and part of the market remains illegal. Production from deliberately inoculated plantations is growing — currently the only sustainable route.
Approaching it
Start with a Western reconstruction, which is a gentle entry. If the register speaks to you, look next for an oil of identified origin. The gap between the two is considerable, and it does not please everyone.
our guide to niche perfume sets out the woody and leather families.