The short answer is: the concentration level of perfume oil (fragrance essence) in relation to the other ingredients.

Eau de Parfum (EdP) contains approximately 15–20% perfume oil.
Eau de Toilette (EdT) contains approximately 5–15% perfume oil.

The difference between “Eau de Parfum (EdP)” and “Eau de Toilette (EdT)” lies in the formula. Specifically, the percentage of perfume oil they contain. The rest — the majority of the formula — is typically alcohol and water.

In addition to EdP and EdT, there are several other classifications, listed here in their order of concentration:

• Parfum – up to 40% fragrance oil
• Eau de Parfum – approx. 15–20%
• Eau de Toilette – approx. 5–15%
• Eau de Cologne – approx. 2–4%
• Eau Fraîche – approx. 1–3%

It is technically correct to refer to all of these as perfumes, regardless of concentration.

Larger, more commercial perfume brands often release several versions of the same fragrance name in different concentrations. Smell them side by side and you will likely notice the difference. A fragrance with a lower concentration of perfume oil is often perceived as lighter and fresher, allowing certain notes to stand out more clearly. The higher the concentration of perfume oil, the richer and heavier the scent becomes, which can enhance specific types of notes and increase longevity on the skin.

Which version you choose ultimately comes down to personal preference

Generally, the higher the concentration of perfume oil, the richer and longer-lasting the fragrance will be on the skin.

Eau de Parfum vs Eau de Toilette

An Eau de Toilette is typically lighter, fresher, and more transparent. It often emphasizes top notes and feels airy and easy to wear — ideal for daytime or warmer climates.

An Eau de Parfum contains a higher concentration of perfume oil, resulting in greater depth and longevity. Base notes tend to be more pronounced, and the fragrance often evolves more slowly and richly over time.

What Is Parfum or Extrait de Parfum?

At the highest end of concentration sits Parfum, also called Extrait de Parfum.

These formulations typically contain between 20% and 30% perfume oil (sometimes more). The result is a denser, more complex, and more long-lasting fragrance experience.

Because of the higher concentration, Extrait fragrances are often more expensive per milliliter yet they require less product per application and tend to sit closer to the skin in a more intimate, powerful way.

This is where master perfumery truly reveals its depth.

NEH and Extrait-Level Concentration

The Altered States Collection is formulated at approximately 25–30% perfume oil concentration.

This places our fragrances within the Extrait de Parfum category, even though they are labeled as Parfum.

We chose this concentration deliberately:

• To allow full depth and longevity
• To support the complete evolution of the raw materials
• To create a rich yet intimate presence on the skin
  

But for us, concentration is only one dimension. True quality depends on:

• The craftsmanship of the perfumer
• The balance of the composition
• The quality of raw materials

The Atelier in Paris

The Altered States Collection is created in close collaboration with the renowned noses at fragrance atelier Flair Paris.

These are scents composed of high-quality, largely natural raw materials, developed with the precision and artistry of master perfumery. Each composition is designed not merely to scent the skin, but to recall your true essence.

At NEH, craftsmanship is foundational. Every detail from the choice of concentration to raw material selection is intentional.

Mindfulness Meets Master Perfumery

At NEH, we explore the intersection of mindfulness, self-healing, and neuroscience. Our fragrances are created to empower, activate, and restore. Crafted from high-quality, largely natural raw materials, each scent is designed to positively influence mind and mood, guiding you toward deeper inner alignment.