A unisex perfume is one not tied to the gender of the wearer. Aroma molecules have no gender; dividing perfume into men's and women's is a commercial convention formed across generations of fragrance families, and wearing the other side's bottle is simply choosing a structure of scent.
A molecule has no gender
Linalool is a molecule with a soft floral, slightly woody smell. It makes up around 31 to 54 percent of neroli oil, distilled from bitter orange blossom, and it is also a main constituent of lavender. Neroli is often placed in women's perfume; lavender is the axis of fougère, a structure usually called masculine. One molecule, two shelves.
That is the short answer to what unisex perfume is. No molecule carries a gender. When a bottle is called men's or women's perfume, the label describes how it is sold, not what is inside. Unisex is the name for bottles that choose neither shelf.
So the question of whether a woman can wear a men's perfume has a simple answer: yes, like any other scent. What changes between shelves is the structure of the scent, not the wearer. A fougère on anyone's skin is still lavender, coumarin and oakmoss.
The human nose has about 400 functional odorant receptor genes, and each molecule activates a combination of receptors. No receptor is reserved for masculine or feminine scent. Differences in smelling between people are real, such as the specific anosmia some people have to certain synthetic musks, but those differences belong to individuals, not to two shelves. What follows looks at how fragrance families acquired masculine and feminine images, and what unisex means in that light.
When perfume split into men's and women's
Professional classifications show traces of the split. In 1984 the Société Française des Parfumeurs published its first perfume classification, and that edition covered only women's fragrances, in five families: floral, chypre, fougère, amber, leather. The 1990 edition added citrus and woody to cover the eau de toilette market. The current table has seven families and applies to women's, men's and unisex perfume.
That a professional classification had to state it applied to women's perfume shows the market was already split in two. But the table shows something else too: once opened to both sides, the families stayed the same. Chypre remained chypre, fougère remained fougère. Families describe structure; gender is a layer placed on top.
A technical difference came with the split. Wikipedia notes that historically women's fragrances tended to have higher concentrations than men's, and that this is changing as fragrances become more unisex. In other words, the division lay not only in scent but also in concentration and format.
The exact moment perfume houses began selling separately to men and women is not given here, because the sources checked do not give a clear date. The library's history of scent classification records systems by year of publication, and none of the scientific line divides smell by gender.
Fougère and the masculine image
In 1882 Houbigant's Fougère Royale set lavender, bergamot, geranium and oakmoss around synthetic coumarin. The bottle named the fougère family. In the twentieth century that structure became the dominant structure of men's perfume, from aftershaves to the herbal bottles of the 1970s and 1980s.
According to the SFP, subfamily C5 Aromatic Fougère is the one tied to most men's perfume of those two decades. From the late 1980s dihydromyrcenol, a molecule smelling of lime, lavender and clean metal, was used at high levels in many fougères; Davidoff's Cool Water of 1988 is the usual example.
The telling detail is in dihydromyrcenol. The library records it as the backbone of fresh masculine and laundry fragrances since the 1980s. The same molecule makes the scent of a men's perfume and the scent of a freshly washed shirt, a shirt anyone might wear.
The masculine image of fougère is therefore a long history of selling, not a property of lavender or coumarin. Lavender appears in many perfumes sold to women; coumarin is the sweet base note of many amber bottles also sold to women.
Flowers and the feminine image
The floral family is the largest in the SFP table, with nine subfamilies from soliflore, a perfume built around one flower, to floral fruity. Its central materials are rose, jasmine, orange flower, ylang ylang, tuberose and iris.
The feminine image of flowers is also a layer placed on top. Rose and geranium share molecules such as geraniol, which makes up around 2 to 26 percent of Damask rose oil and 7 to 30 percent of geranium oil; geranium is a familiar heart of fougère. Orange blossom gives neroli, and neroli is a pillar of eau de Cologne, the citrus water Farina made in Köln from 1709 and still produced today.
When the first SFP table covered only women's perfume, floral headed the list. Yet that same table also had fougère and leather, two families later tied to the masculine image. In 1984, then, structures the market called masculine were already present in a classification of women's perfume.
From the side of materials, the line is even fainter. A bottle of rose or jasmine oil says neither men nor women. It gives the name of the plant, the part distilled, and where it grew.
Unisex today
In 1994 Calvin Klein's CK One was launched, composed by Alberto Morillas and Harry Fremont. According to Wikipedia it was the first unisex fragrance to gain wide popularity in the United States, and has also been described as the first fragrance openly marketed as unisex.
The citrus family is where unisex seems most at home. Eau de Cologne has existed for more than three centuries, and bergamot, lemon and orange peel suggest neither a masculine nor a feminine image with any clarity. Minimalist structures built on a few woody and amber molecules, such as the pairing of ambroxide and Iso E Super, are also often sold without gender.
Today the word unisex has two meanings. The first is a sales strategy: a bottle placed on neither the men's nor the women's shelf. The second is a way of building scent: avoiding signs that have been gendered, such as an obvious fougère or a very sweet floral. The two often go together, but not always.
Even the library's material data still carry this language. The note on Karanal, a woody amber molecule, says it is used at low levels to add radiance and dryness to woody amber accords in masculine and unisex fragrance. Masculine and unisex here mark where the molecule is usually used in the market, not a property of the molecule.
Following Wikipedia's note on concentration, the move toward unisex perfume is also blurring the difference in strength between men's and women's fragrance. What remains is the fragrance family, and the family never had a gender.
Naming by material
A bottle of essential oil carries the name of a plant: lavender, vetiver, patchouli, bergamot. The name says nothing about who will wear it. It says what the bottle holds, from which part of the plant, distilled where. That is how the Lê Mai oil cabinet names its bottles, and how the library is arranged.
Naming by material leads the nose to the right question. Instead of asking who a bottle is for, the question becomes: which fragrance family does this scent belong to, how does it change after an hour, does it suit a structure already liked. These questions have answers on a blotter.
The piece Fougère · lavender and a forest that does not exist rebuilds the fougère structure with essential oils. The label of that blend carries only the names of its materials.
The gender of a scent, if it has one, lies with whoever tells its story. The bottle holds only molecules.
A molecule does not ask who will smell it.
The shelf was built after the bottle.
The name of the plant remains the most exact name.