A small gland pouch beneath the belly of an antlerless deer. Dark brown grains in which muscone makes up only about 0.5 to 2 percent. And one word, musk, which now sits on the labels of a great many perfumes that contain nothing from that deer.
A Small Pouch and a Large Word
The musk deer is a small deer without antlers that lives in the mountain forests of Asia, from Siberia across the Himalaya to southern China. The male carries a gland pouch under its belly. The secretion inside dries into dark brown grains, known in trade as musk grains. This is deer musk, the material that gave its name to an entire family of scent.
The grains are described as warm and powdery, close to the smell of skin, faintly animal, with an edge of dried flowers and honey. They diffuse widely in tiny amounts and last a very long time. In classical perfumery musk was used as a tincture: dried grains steeped in ethanol for months, then filtered.
Its trade history carries a place name. Tonkin musk, or Tonquin musk, takes its name from Tonkin, the colonial European name for northern Vietnam. Musk that travelled through Yunnan and Tonkin was graded highly in nineteenth century trade. The name marks a trade route, not a separate species of deer.
Today the word musk on a perfume bottle almost always refers to a synthetic molecule. Between the deer and the label lie a century of chemistry and a body of law on the trade in wild animals.
The Musk Deer and CITES
The musk pod sits inside the body of the deer, and historically taking the pod meant killing the animal. When the price of musk was high, hunting pressure on wild musk deer populations rose with it.
CITES currently lists the entire genus Moschus in Appendix II, which means international trade requires permits and evidence that it does not harm the survival of the species. The populations of Afghanistan, Bhutan, India, Myanmar, Nepal and Pakistan are in Appendix I, the strictest level, which all but excludes commercial trade.
China has farmed musk deer since 1958 and developed ways to collect musk from live animals, mainly for traditional medicine. In the international fragrance trade deer musk has been almost absent since the late twentieth century. In Vietnam, trade in natural musk falls under wildlife law and the rules that implement CITES.
So the word musk on a retail perfume today almost certainly does not come from the deer. The better question is which molecule it comes from, and which generation that molecule belongs to.
Muscone and the Macrocyclic Musks
The main odorant of deer musk is muscone. Heinrich Walbaum isolated it in 1906. Twenty years later, in 1926, Leopold Ružička showed that muscone is a ketone with a ring of fifteen carbon atoms. The result changed how chemists thought about large carbon rings. Ružička received the 1939 Nobel Prize in Chemistry for work on polymethylenes and terpenes.
In the same year Ružička determined the structure of civetone from civet, also a large ring ketone. Two different animals, two different glands, one molecular geometry. This opened the family of macrocyclic musks: ketones, lactones and diesters with rings of fifteen atoms or more.
Cyclopentadecanone, sold as Exaltone, is muscone without one methyl group. Ružička made it while working with the Geneva company that later became Firmenich. Its smell is described as a dry, clean musk, waxy and powdery, with less animal character than muscone. Ethylene brassylate is a macrocyclic diester made from brassylic acid and ethylene glycol; brassylic acid can be obtained from erucic acid in rapeseed oil, so the starting material is plant derived. Its low cost and high stability have made it one of the highest volume macrocyclic musks.
Natural muscone is the (R) enantiomer. Commercial muscone is synthetic, either racemic or enriched in one enantiomer. It costs more than most synthetic musks and is found mainly in fine fragrance. In the IFRA 51 index muscone has no dedicated restricting standard.
Nitro and Polycyclic Musks: Galaxolide, Tonalide
The first synthetic musk came not from a perfume laboratory but from research on explosives. In 1888 Albert Baur obtained a musky nitro compound while working with TNT type substances. Musk ketone, patented in 1894, became the base of many classical perfumes. Musk ambrette, musk xylene and other nitro musks followed.
The nitro generation was cheap and stable, but from the 1980s data on bioaccumulation and on light reactions on skin led to a series of bans. IFRA prohibited musk ambrette in 2006, musk moskene and musk tibetene in 2008, and musk xylene in 2009. Musk ketone remains permitted under a specification standard, and in the EU it sits in Annex III with a maximum of 1.4 percent in fine fragrance.
The next generation was the polycyclic musks. Galaxolide was discovered by IFF chemists in 1965 and soon became the most used synthetic musk in the world. It is cheap, stable in alkaline media, and smells clean and sweet with floral and woody touches, close to freshly laundered cloth. Those qualities carried it into soap, detergent and fabric softener. Tonalide, a polycyclic musk of the same period, often travels with galaxolide; the two once accounted for most of the world's synthetic musk volume.
From the 1990s galaxolide was detected in wastewater, sludge and aquatic organisms. Environmental assessments in Europe and North America followed, and the industry gradually shifted toward macrocyclic and more degradable alicyclic musks. EU Regulation 2023/1545 adds hexamethylindanopyran, the chemical name under which galaxolide appears on the list, to the allergens that must be named on the label above 0.001 percent in leave on products. Tonalide has its own limits in EU Annex III, 2.5 percent in fine fragrance.
Ambrette Seed: Musk from a Plant
Some plants also produce large ring molecules with a musky smell. Abelmoschus moschatus belongs to the mallow family, related to cotton and hibiscus. Its seeds are harvested, dried and steam distilled to give ambrette seed oil. The main producers are India, Madagascar and Indonesia.
The largest part of ambrette seed oil is not what carries the musk. Farnesyl acetate makes up about 30 to 65 percent and farnesol 3 to 39 percent. The molecule behind the musky note is ambrettolide, a lactone with a seventeen membered ring, at about 7.6 to 14.7 percent. An uncommon structure among commercial essential oils, held inside a small seed.
The high share of farnesol and farnesyl acetate makes ambrette oil prone to oxidation, so it needs a dark bottle, a tight seal and cold storage. Besides the oil there are an absolute and a CO2 extract of the seed, each with a different scent profile. Angelica root is another plant source, containing pentadecanolide, also a macrocyclic lactone.
These materials are costly and used in small amounts. They cannot replace the tonnage of synthetic musk in laundry products, but they give perfume a musk of plant origin, warm and close to animal musk, unlike the flat cleanness of the polycyclics.
White Musk on Skin
Musk is the slowest base note in a formula. The molecules are large, with molecular weights around 240 to 270, and evaporate very slowly, so they are often what remains on skin after many hours. White musk is the common name for a clean musk without animal character, built from synthetic musk molecules such as galaxolide, habanolide, ethylene brassylate or helvetolide. Habanolide is described as freshly washed linen with a slightly metallic edge. Helvetolide, introduced by Firmenich in 1990, was the first commercial alicyclic musk, with a pear like nuance.
One feature of musk is that not everyone can smell it. Many people have a specific anosmia to certain musk molecules: the molecule is on the skin, but that person does not perceive it. For this reason formulas often use several musks at once, each filling a gap for people who miss another. The phenomenon is discussed further in a smell half the room cannot detect.
Each generation of musk carries its own kind of clean and warm. Muscone is round and milky with a trace of skin. Nitro musks are sweet and a little dusty. Polycyclics are sweet and floral, tied to the smell of laundry. Macrocyclics are soft and powdery. Alicyclics are bright with a fruity edge. Ambrette is warm, the closest of all to animal musk. Reading a musk note on a blotter means reading which historical layer it belongs to.
The Lê Mai White Musk perfume belongs to this line: a clean musk note built from molecules, with no material from the musk deer. The move from animal to molecule was not only a matter of ethics. The chemistry of Ružička and those who came after him made it possible, one ring at a time.
A gland pouch, then a ring of fifteen atoms.
The word musk stayed. The deer is no longer needed.
The warm smell of skin is now a question of chemistry.