Why don’t two fragrances with the same notes smell the same?

Two perfumes can display almost the same olfactory pyramid - for example, oud, rose, vanilla, and musk - and yet create a very different impression. This is not a contradiction: a list of notes does not by itself describe a perfume's formula.

To understand this difference, you need to look at what lies behind the words used on a perfume information sheet: the raw materials, molecules, accords, proportions, extraction methods, volatility, and the way the composition evolves on the skin.

The first mistake: believing that the same notes mean the same formula

A “note” is above all a way of describing what one perceives or what the brand wants to highlight. It is not necessarily a raw material present as such in the concentrate.

Thus, the mention “oud” may refer to an olfactory facet, an accord built around several materials, a natural oud oil, or a particular aromatic ingredient. The same logic applies to musk, amber, leather, vanilla, or sandalwood.

An olfactory pyramid is therefore a descriptive representation, not the complete perfume formula. Two compositions can list the same notes while using different palettes and proportions.

1. Raw materials are not interchangeable

The word “rose” is not enough to determine the smell of a perfume. A natural material can vary according to its origin, the part of the plant used, the extraction process, and the characteristics of the batch. Perfumery materials can also be obtained through different extraction or transformation methods.

Natural materials and synthetic ingredients are part of the perfumer's palette. The industry uses both to build fragrances, particularly to work on consistency, precision, diffusion, or certain olfactory facets. sourceIFRA - How is fragrance made

2. The same material can be used in different forms

The olfactory result also depends on the form in which a material is incorporated into a composition.

• An essential oil is a specific type of material obtained through extraction, often by distillation or expression, depending on the material.
• An absolute generally comes from a solvent extraction process that makes it possible to recover a more complex aromatic material than certain essential oils.
• A resinoid is obtained from resinous or balsamic materials through extraction.
• An extract can refer to different preparations depending on the material and the process used.

These categories are therefore not simply synonyms. The transformation process contributes to the characteristics of the resulting material.

3. Proportions completely change the result

This is probably one of the most important reasons. Two fragrances can use ingredients belonging to the same families while dosing them very differently.

Imagine a composition built around four major facets: oud, rose, vanilla, and musk. In one formula, the oud may dominate and the rose serve to provide a floral opening. In another, the rose may be much more prominent, while the vanilla and musk create a softer base.

The words remain identical on the product page, but the olfactory balance changes.

4. Accords create a scent that does not exist in a single material

An accord is a combination of several materials designed to produce a coherent olfactory impression.

This is essential for understanding oriental fragrances. An “oud” described on a product page may be a facet constructed from several materials. An “amber” may also be an accord rather than a single material. Likewise, an impression of clean, powdery, or animalic musk can be achieved through different combinations.

The final result therefore depends on the interaction between the ingredients, not only on their isolated presence.

5. Molecules influence the character of the composition

An aromatic raw material is itself composed of molecules. Some molecules may be of natural origin, while others may be obtained through synthesis. “Molecule” therefore does not automatically mean “artificial.”

Modern perfumery combines natural and synthetic ingredients. IFRA describes a palette comprising natural materials and synthetic molecules used to construct fragrances. sourceIFRA - How is fragrance made

A difference in molecular composition can modify the texture, diffusion, freshness, softness, depth, or longevity of an olfactory impression.

6. Volatility makes a fragrance evolve over time

A fragrance is not perceived as a motionless photograph. Its composition evolves as its different components evaporate and diffuse.

Some materials or molecules are more volatile and contribute more to the initial impression. Others remain perceptible for longer and contribute to the base of the composition.

This is one reason why two perfumes with the same advertised notes may start similarly and then diverge after a few dozen minutes or several hours.

7. Skin can alter perception

A perfume is perceived in a real-world context: temperature, humidity, skin, amount applied, hydration, and environment can modify the olfactory experience.

It is therefore necessary to distinguish between two phenomena: the difference between two formulas and the difference in perception of the same formula depending on the person or the application conditions.

The skin does not necessarily transform a perfume into a different composition, but it can influence its diffusion and how certain facets are perceived over time.

8. Extraction can change the character of a material

The same plant origin does not necessarily produce the same result depending on the method used to obtain the odorant. Distillation, expression, solvent extraction, and other processes do not recover exactly the same set of compounds.

For complex natural materials, geographical origin, the part of the plant, and the extraction method are among the elements that can be distinguished in the nomenclature systems used by the industry. sourceIFRA - Transparency List

This helps explain why two compositions containing a “rose” or a “citrus” can display noticeably different nuances.

Example: two perfumes with “oud, rose, vanilla, musk”

The two descriptions may be similar, even though the olfactory experience is different. The table is obviously only an educational model: without analyzing the formula, the ingredients or their proportions cannot be precisely inferred from a pyramid.

What an olfactory pyramid really tells you

A fragrance profile is useful for identifying the main olfactory directions presented: highlighted materials, families, facets, and development described by the brand.

It generally does not make it possible to reconstruct the exact formula. A fragrance is a combination of ingredients intended to produce a particular scent, and its creation is based on the construction and balance of that composition. sourceIFRA - What is a fragrance?

How to compare two perfumes with the same notes

1. Look at the olfactory families. Two fragrances may share four notes but belong to very different profiles.
2. Observe the stated order and development. The same material may appear at different stages of perception.
3. Analyze the dominant accords. “Oud” or “amber” does not necessarily mean a single material.
4. Look at the described texture. Dry, creamy, powdery, smoky, resinous, fresh, or animalic characteristics provide more information than a simple list of notes.
5. Test on skin whenever possible. Perception and diffusion may evolve after application.

Key takeaway

Same notes ≠ same fragrance.

The difference may come from the material used, its origin and extraction method, the combination of several ingredients in an accord, the proportions, volatility, the structure of the formula, and the way the fragrance diffuses on the skin.

This is precisely why an olfactory pyramid should be read as a reading map, not as a recipe.

To go further

• Note, accord, raw material, molecule: what is the difference in perfumery?
• Essential oil, absolute, extract, resinoid: what are the differences?
• How are raw materials extracted in perfumery?
• Olfaction and method: learning to smell, analyze, and describe a fragrance
• Science and production of oriental perfume: understanding how a fragrance is created