What Is an Overdose? Not an Accident, a Decision
In perfumery, an overdose is using a molecule far above its usual dose, deliberately and at the centre of the composition. It is not a mistake; it is a signature method. Many turning points of modern perfumery begin with an overdose: the classic aldehydic scents in which aldehydes were used at unusual doses, Hedione putting its stamp on fresh floral scents, Iso E Super becoming a perfume on its own, ethyl maltol launching the gourmand movement, Ambroxan becoming the backbone of today's masculine scents.
The reason an overdose works is that some molecules change character with dose. A substance that is a raw material at low dose becomes an "effect" at high dose: Hedione gives jasmine volume at low dose, while at high dose it creates an airy, luminous, transparent space. Iso E Super is a woody filler at low dose and a velvety aura at high dose.
This article explains which molecules can carry an overdose, how it is tried and where its limits lie.
Molecules That Can Carry an Overdose
Not every molecule becomes beautiful at high dose; most overwhelm, turn sharp or stay one-dimensional. What those that can carry an overdose have in common is a character that remains transparent, soft and untiring to the sense of smell even at high dose.
| Molecule | Usual dose | Effect in overdose | Limit |
|---|---|---|---|
| Hedione | 2–10% | Airy, luminous, transparent florality; a scent that "breathes" | No IFRA restriction; above 30% the formula thins out |
| Iso E Super | 3–15% | Velvety woody aura, skin-close diffusion | IFRA restricted; limit depends on category |
| Ambroxan / Cetalox | 1–5% | Mineral, salty amber; long-lasting and diffusive | Harsh at high dose; quality differences are marked |
| Ethyl maltol | 0.1–1% | Cotton candy, caramel; gourmand signature | Solubility and colour; sugary fatigue |
| Calone | 0.1–1% | Sea breeze, watermelon rind; the aquatic movement | Becomes a cliche very quickly |
| Aldehydes (C-10, C-11, C-12) | 0.1–1% | Bright, soapy, "sparkling" opening | Sharpness; metallic if not balanced |
| White musks (Galaxolide, Habanolide) | 5–15% | Clean, skin-like, laundry freshness | Partial anosmia is common; not everyone perceives them the same |
The doses in the table are on the concentrate and are for orientation; every formula has its own balance. Three to ten times the usual dose is the region where an overdose begins.
How to Try an Overdose: Step by Step
An overdose is not using a molecule on its own at a high dose; it is building the molecule's surroundings to suit it.
- Get to know the molecule on its own
Follow the 10% dilution on a strip and on skin for a few hours. An overdose cannot be planned without knowing what the molecule turns into at high dose.
- Build a dose ladder
Prepare the same skeleton formula in four versions containing the molecule at 5%, 15%, 30% and 50%. To keep the ratios of the other components constant, take the molecule's increase out of the solvent or the most neutral component.
- Evaluate blind
Smell the four strips unlabelled, with several people and over several hours. Find the dose at which it stops being a "raw material" and becomes an "effect".
- Simplify the surroundings
The more dominant the overdosed molecule, the simpler the rest of the formula must be. In a Hedione overdose, two or three supporting notes are enough instead of ten floral notes.
- Test longevity and the relationship with skin
At high dose some molecules behave unexpectedly on skin: Iso E Super vanishes on some people, musks are not perceived at all by some noses. Try it on several different skins.
- Do the IFRA calculation
Check the molecule's limit in the product category. The upper bound of the overdose is that limit divided by the fragrance oil level.
Risks and Limits
An overdose goes wrong in four ways.
Anosmia. For musks and some woody molecules (Iso E Super included), part of the population has partial or complete anosmia. An overdose built on these molecules gets the reaction "it doesn't smell of anything" from some customers. The solution is to spread the signature across two different molecule families.
Fatigue. A single character at high dose tires the wearer after a few hours and the nose adapts to it; the person stops noticing their perfume. Transparent molecules carry little of this risk, sweet and dense molecules a great deal.
Cliche. Once an overdose succeeds it is imitated and quickly becomes the stamp of an era. Calone and ethyl maltol went through this. The way to keep an overdose fresh is to pair it with unexpected surroundings.
Technical limits. At high dose, solid molecules cause solubility problems (ethyl maltol), some change the colour, some hit the IFRA limit. An overdose formula must pass stability and compatibility testing more strictly than a normal formula.
Frequently Asked Questions
The most common questions about the overdose technique.
At what dose does an overdose begin?
Can an overdose be done with any molecule?
Does an overdose run into IFRA?
What percentage of the formula can the overdosed molecule be?
My customer finds the overdosed scent "weak"; why?
Does an overdose increase longevity?
Is an overdose a way to make a cheap formula?
Which examples should I start with?
Related articles
What Is Iso E Super? Uses and Usage Rates in Perfumery
Iso E Super is one of the most widely used aroma chemicals in modern perfumery — a dry, velvety, woody-amber molecule that smooths and expands any fragrance formula. Learn how it works, how much to use, and how to work with it safely.
Read →What Is Hedione HC? Uses and Usage Rates in Perfumery
Hedione HC is the high-cis isomer version of classic Hedione — a transparent, luminous diffuser that lends modern fragrances their airy, aqueous-floral radiance. Learn its scent profile, recommended usage rates, and formulation tips.
Read →Odor Threshold & Dosage Optimisation in Fragrance Formulation
Odor threshold determines how much of a molecule your nose actually detects — not how much you've added. Master threshold-aware dosage to build balanced, intentional fragrances.
Read →