Oud, agarwood, oudh and attar: the words explained

The short version

• Oud, oudh, agarwood, aloeswood and gaharu are all names for the same resin-filled wood.
• On a label, "oud" can mean natural agarwood oil, a blend, or an accord built from other materials, so ask the brand which.
• A traditional attar is a natural material distilled into sandalwood oil; elsewhere, the word is used far more loosely.

Agarwood: wood that forms around a wound

Agarwood is dark, resin-filled wood from certain trees, mainly Aquilaria and Gyrinops. They grow wild from north-east India through South-east Asia.

Their healthy wood is pale and doesn't smell of agarwood. That changes when a tree is wounded and fungi or other microbes get in.

The tree fights back with a fragrant resin around the wound. It helps contain the infection.

Over the years the resin-soaked wood turns dark and dense. The richest pieces sink in water. How it all works still isn't fully understood.

This is the wood that's cut out and traded. A healthy tree is worth very little. Only an estimated 1 to 10 per cent of wild trees ever form it.

That scarcity is a big part of the price. Depending on grade, chips sell for tens to thousands of pounds a kilo.

The smell comes from well over a hundred compounds, mostly in two families. One is the sesquiterpenes, a large group of plant scent compounds. Agarwood's include agarospirol and the agarofurans.

The other is the 2-(2-phenylethyl)chromones, bigger molecules the resin is rich in. Many barely evaporate at room temperature.

The mix varies with species, tree age, grade and processing. So one agarwood can smell quite different from the next.

Why it's protected

Demand has put wild trees under heavy pressure. In 1995 Aquilaria malaccensis went on Appendix II of CITES, the treaty on trade in wild species. All Aquilaria and Gyrinops species followed in 2004.

Appendix II doesn't ban trade. Shipments abroad need permits. These should only be granted if the trade is legal and won't harm the species' survival in the wild.

Plantations in several Asian countries now trigger agarwood on purpose. Growers wound the trunks, inject lab-grown fungi, or use chemicals that set off the tree's defences. They supply a growing share of the trade, but wild agarwood is still traded and in demand.

The names, one by one

Traded for more than 2,000 years, agarwood picked up a name in almost every market it reached.

• Oud, oudh: two spellings of the Arabic ʿūd, which means wood and, in perfume, agarwood.
• Agarwood: the usual English and scientific name. In several South Asian languages it's "agar".
• Aloeswood, aloes: older English names, unrelated to aloe vera. The "aloes" in older Bibles is usually taken to be agarwood.
• Eaglewood: another old English trade name.
• Gaharu: the Malay and Indonesian name.
• Jinkō (or jinkoh): the Japanese name. Kyara is the most prized Japanese grade.
• Dehn al oud (or dahn al oud): literally "oil of oud" in Arabic, from duhn, oil.
• Bakhoor (or bukhoor): incense, usually scented wood chips.
• Attar: from the Arabic ʿiṭr, perfume.

From wood to oil: dehn al oud

The oil is distilled from chipped, crushed wood in a still. In hydrodistillation the wood sits in boiling water. In steam distillation, steam is passed through it.

Both work the same way. Scent compounds in plant oils mostly boil at 150 to 300°C, far hotter than water. But oil and water don't mix, so each gives off its own vapour.

The mixture boils once the two vapour pressures add up to the air pressure. That happens below 100°C. So steam carries the scent out without heating it enough to break it down.

A condenser cools the vapour back to liquid. The oil doesn't dissolve in water, so it settles out as its own layer.

In one lab study, distilling hotter gave a darker oil with more compounds.

A report on Malaysia's agarwood trade found so-called agarwood oil was often synthetic, and real oil often diluted with cheaper oils. Telling natural oil from a fake with confidence can take lab testing.

Burning it: bakhoor and incense

Agarwood has been burnt as incense for centuries, in worship and daily life, across the Middle East and South and East Asia.

In the Gulf, the best-known form is bakhoor: wood chips soaked in perfumed oil, often with resins, spices and other aromatics. They're burnt on hot charcoal in a mabkhara burner. The smoke scents the room, and often clothes and hair.

In kōdō, Japan's "way of incense", the wood isn't set alight. A sliver is warmed on a thin mica plate over charcoal in a cup of ash.

Unheated, the wood has only a faint scent. Heat breaks some of its heavy chromones into smaller aromatic compounds, such as benzylacetone. These drift into the air easily.

One Japanese study found these compounds above heated agarwood, but not in the wood itself. In that study, the distilled oil was mostly sesquiterpenes. The main chromone it tracked stayed in the still.

Heated alone, that chromone gave off benzylacetone. This helps explain why a warmed chip doesn't smell quite like a drop of oil.

What an attar actually is

Kannauj, a town in Uttar Pradesh, has long been known for attar. Its classic method is deg-bhapka.

Flowers, herbs or other materials are heated with water in a clay-sealed copper still, the deg. Steam runs along a bamboo pipe into the bhapka, a copper pot of sandalwood oil.

The bhapka sits in a trough of cool water, which turns the vapour back to liquid. The scent compounds dissolve poorly in water but well in oil. So the sandalwood oil takes them up.

Sandalwood oil is mostly alpha- and beta-santalol, two closely related compounds largely behind its smell. They become part of the attar too. A traditional attar, then, is a natural material distilled straight into sandalwood oil, with no alcohol.

Outside that tradition, the word is used far more loosely. The same Malaysian report found "minyak attar" used simply to mean alcohol-free perfume. It also found agarwood oil sold as attars, alone or blended.

New to oils? Read how perfume oils wear and how to choose one.

What "oud" on a perfume label can mean

On a label, "oud" usually means one of three things:

• Natural agarwood oil in the formula. It's costly.
• A blend: some natural oil with other materials.
• An oud accord: an impression of oud built from other materials.

An accord is a set of materials blended to work together, the way several notes make one chord. Perfumers sometimes build one to recreate a natural scent.

An oud accord pairs aroma molecules, many made in a lab, with other materials. It can suggest agarwood whether or not any is in it. Natural oil's mix, by contrast, is set by the tree.

A 2021 review says chemical substitutes for agarwood exist. But in its authors' view, they don't come close to the natural material.

Ingredient lists won't settle it. Under EU rules, a fragrance blend can be listed as one word, "Parfum", with only certain allergens named. Notes describe how a perfume smells, not what went into it (more in our guide to woody fragrances).

Natural oil and accords smell different, and which you prefer is personal. If it matters, ask the brand which you're getting.

Sources

1. Shivanand P, Arbie NF, Krishnamoorthy S, Ahmad N. Agarwood: the fragrant molecules of a wounded tree. Molecules, 2022; 27(11): 3386. doi:10.3390/molecules27113386
2. Tan CS, Isa NM, Ismail I, Zainal Z. Agarwood induction: current developments and future perspectives. Frontiers in Plant Science, 2019; 10: 122. doi:10.3389/fpls.2019.00122
3. Baig A, Akram A, Lin M-K. Agarwood in the modern era: integrating biotechnology and pharmacology for sustainable use. International Journal of Molecular Sciences, 2025; 26(17): 8468. doi:10.3390/ijms26178468
4. Gao M, Han X, Sun Y, et al. Overview of sesquiterpenes and chromones of agarwood originating from four main species of the genus Aquilaria. RSC Advances, 2019; 9(8): 4113-4130. doi:10.1039/c8ra09409h
5. López-Sampson A, Page T. History of use and trade of agarwood. Economic Botany, 2018; 72(1): 107-129. doi:10.1007/s12231-018-9408-4
6. Lim TW, Noorainie AA. Wood for the trees: a review of the agarwood (gaharu) trade in Malaysia. TRAFFIC Southeast Asia, for the CITES Secretariat, 2010. traffic.org
7. Yuan Y, Yang M, Zhao Y, Qiu Z. Unraveling the science of "sinking and dark-colored" superior agarwood through density, color, and metabolomics. RSC Advances, 2026. doi:10.1039/d5ra08081a
8. Mongabay. Global agarwood trade heavily dependent on wild, threatened trees: study. April 2025. news.mongabay.com
9. CITES Appendices, definitions as reproduced by the Encyclopedia of Life. eol.org
10. Pornpunyapat J, Chetpattananondh P, Tongurai C. Mathematical modeling for extraction of essential oil from Aquilaria crassna by hydrodistillation and quality of agarwood oil. Bangladesh Journal of Pharmacology, 2011; 6: 18-24. doi:10.3329/bjp.v6i1.7902
11. Axtell BL, Fairman RM. Minor oil crops, Part III: Minor essential oil crops (Distillation of essential oils). FAO Agricultural Services Bulletin 94. Food and Agriculture Organization of the United Nations, Rome, 1992. fao.org
12. Clark J. Immiscible liquids and steam distillation. Chemguide. chemguide.co.uk
13. Nichols L. Steam distillation: separation theory. In: Organic Chemistry Lab Techniques. Chemistry LibreTexts. chem.libretexts.org
14. Kliszcz A, Danel A, Puła J, et al. Fleeting beauty: the world of plant fragrances and their application. Molecules, 2021; 26(9): 2473. doi:10.3390/molecules26092473
15. Hashimoto K, Nakahara S, Inoue T, et al. A new chromone from agarwood and pyrolysis products of chromone derivatives. Chemical and Pharmaceutical Bulletin, 1985; 33(11): 5088-5091. doi:10.1248/cpb.33.5088
16. Takamatsu S, Ito M. Agarotetrol: a source compound for low molecular weight aromatic compounds from agarwood heating. Journal of Natural Medicines, 2018; 72(2): 537-541. doi:10.1007/s11418-018-1185-y
17. Kao W-Y, Hsiang C-Y, Ho S-C, Ho T-Y, Lee K-T. Chemical profiles of incense smoke ingredients from agarwood by headspace gas chromatography-tandem mass spectrometry. Molecules, 2018; 23(11): 2969. doi:10.3390/molecules23112969
18. Castro KP, Ito M. Individual and combined inhalational sedative effects in mice of low molecular weight aromatic compounds found in agarwood aroma. Molecules, 2021; 26(5): 1320. doi:10.3390/molecules26051320
19. Visit Qatar. Bukhoor. visitqatar.com
20. Aljohani LM, Shaikh ST, Bawazir AA, et al. Assessing the effects of bakhour on pulmonary functions in young adults in Saudi Arabia. Cureus, 2025; 17(8): e89367. doi:10.7759/cureus.89367
21. Jareebi MA, et al. Exploring the relationship between bakhour use and respiratory health: a cross-sectional study in the Jazan region, Saudi Arabia. International Journal of General Medicine, 2024; 17: 2833-2845. doi:10.2147/IJGM.S461772
22. VCUarts Qatar (Virginia Commonwealth University School of the Arts in Qatar). Learning from Mabkhara, exhibition news, 2012. qatar.vcu.edu
23. Berrod L-T. "Kodo", the art of listening to fragrances. Pen, 14 January 2022. pen-online.com
24. Lane EW. An Arabic-English Lexicon: عود (ʿūd); عطر (ʿiṭr); دهن (duhn). ʿūd, ʿiṭr, duhn
25. Salmone HA. An Advanced Learner's Arabic-English Dictionary (1889): دهن (duhn). arabiclexicon.hawramani.com
26. Dictionary.com. Oud; Attar. dictionary.com/browse/oud, dictionary.com/browse/attar
27. Jain A. Kannauj: perfume capital of India. Live History India, 16 September 2020. livehistoryindia.com
28. Pal S. This Indian town has been bottling the scent of rain for thousands of years. The Better India, 24 June 2016. thebetterindia.com
29. Dutta T. How perfumers in India's fragrance capital bottle the sweet smell of rain. The National, 4 August 2023. thenationalnews.com
30. Chatterjee A. Kannauj's mitti attar: the scent of rain. Outlook Traveller, updated 24 August 2023. outlooktraveller.com
31. Kulshrestha U. The art of aromas: ittar industry of Kannauj. Sahapedia. sahapedia.org
32. Kucharska M, Frydrych B, Wesolowski W, Szymanska JA, Kilanowicz A. A comparison of the composition of selected commercial sandalwood oils with the international standard. Molecules, 2021; 26(8): 2249. doi:10.3390/molecules26082249
33. Zha W, Zhang F, Shao J, et al. Rationally engineering santalene synthase to readjust the component ratio of sandalwood oil. Nature Communications, 2022; 13: 2508. doi:10.1038/s41467-022-30294-8
34. Spence C, Di Stefano N. Crossmodal harmony: looking for the meaning of harmony beyond hearing. i-Perception, 2022; 13(1). doi:10.1177/20416695211073817
35. Chazot I, Wicky É, Borloz S, et al. NOMEN: a classification of methods used to create odourous compositions with a historical dimension. Open Research Europe, 2025; 5: 383. doi:10.12688/openreseurope.21121.1
36. European Commission. Fragrance allergens labelling. ec.europa.eu
37. UL Solutions. EU amends Cosmetics Regulation regarding fragrance allergens. August 2023. ul.com