In short
Exaltolide is the Firmenich name for pentadecanolide, a macrocyclic musk lactone that also occurs in angelica root. It is one of the most refined, natural-smelling musks.
What Exaltolide smells like
Exaltolide (pentadecanolide, Firmenich) is an extremely fine and elegant musk, among the finest synthetic musk notes and of fairly natural quality, in Firmenich's description. Scentspiracy finds a medium-strength musk with a sweet, skin-like character, floral and ambrette undertones and strong tenacity; a glossary a clean, sweet, transparent musk hard to detect on its own. A patent notes that the related pentadecenolides have a more animal character than pentadecanolide.
- Leading note
- Fine skin-like musk
- Supporting facets
- Sweet
- Faint facets
- Ambrette, floral, animalic
- Character
- Soft, elegant, transparent, tenacious
What makes Exaltolide distinctive
A fine, transparent musk that reads as skin rather than as perfume.
Where the descriptions disagree: Firmenich and suppliers describe a distinct sweet musk; one glossary finds it nearly invisible alone.
How Exaltolide is used
Used as an elegant, transparent musk base in fine fragrance.
Typical role: fixative (slow to evaporate; helps a blend last and holds lighter notes).
How Exaltolide differs from similar materials
- Exaltone
- Exaltone, a ketone, is warmer, more animalic and powdery; Exaltolide, a lactone, is cleaner, sweeter and skin-like.
- Habanolide
- Habanolide adds a hot-iron metallic edge to a clean musk; Exaltolide is softer and more skin-like.
- Ambrettolide
- Ambrettolide is fruitier, with ambrette and red-fruit sweetness; Exaltolide is the cleaner, finer musk.
- Musk R1
- Musk R1 (11-oxahexadecanolide) was found equal in character and intensity to pentadecanolide by its 1962 discoverers. (compared directly by a cited source)
An asterisk marks a difference that a cited source states directly. The others compare the published descriptions of each material. Smell varies with grade, supplier and dilution; compare them side by side on blotters before substituting one for another.
Formulation considerations
A low-melting solid; dissolve before use. Covered by an IFRA Standard.
Identity and classification
- Type
- Aroma chemical
- Origin
- Synthetic
- Odour family
- Musky / Powdery
- Note position
- Base note
- Physical form at room temperature
- Solid
- Also known as
- Pentadecanolide, Cyclopentadecanolide
- CAS number
- 106-02-5
- Molecular formula
- C15H28O2
- Molecular weight
- 240.38 g/mol
- IUPAC name
- oxacyclohexadecan-2-one
The CAS number, formula and molecular weight are taken from PubChem compound 235414, whose own record lists this CAS number; checked 19 October 2026.
Safety and compliance
The IFRA Standards Library lists a Standard covering Exaltolide:
- "Cyclopentadecanolide" — Restriction, 49th Amendment, published 2020-01
Limits differ by product category and are set out in the Standard itself; this page does not reproduce them. The list above reflects the library as read on 19 October 2026.
Hazard classification of the neat substance, as PubChem summarises it, read 26 October 2026. Companies notifying the ECHA C&L Inventory classify it (1,826 reports): H411 toxic to aquatic life with long lasting effects (82.8% of reports); H317 may cause an allergic skin reaction (13.5% of reports). 270 of the reports find it does not meet the hazard criteria. A skin sensitiser classification concerns handling the neat material and the dose in a finished product; the IFRA Standards, where they apply, set the limits. Unless it is harmonised, this is the notifiers' own classification, not a binding one.
This page is general information, not a safety assessment or a specification. Confirm identity, composition, IFRA status and allergen content from your supplier's documents for the lot you hold.
Materials it works with
-
Galaxolide
Aroma chemical · Musky / Floral — musky, clean, sweet, floral
-
Isoambrettolide
Aroma chemical · Musky / Fruity — musky, powdery, fruity, soft
-
Exaltone
Aroma chemical · Musky / Animalic — musky, animalic, warm
Exaltolide is also suggested as a partner on the pages for Angelica Root Oil, Globanone, Muscone, Musk R1 and Velvione.
Used in formulas and accords
Used in 37 published formulas
Exaltolide is an ingredient in 30 perfume formulas, 6 accords and 1 base in the Formula & Accord Library.
Community formulas
RUŌOD House Originals
Original compositions by RUŌOD House.
Further reading
Questions about Exaltolide
Is Exaltolide natural or synthetic?
Exaltolide is synthetic — it is made by chemical synthesis.
What is the CAS number of Exaltolide?
106-02-5. It was checked against PubChem on 19 October 2026.
Which published formulas use Exaltolide?
Exaltolide is used in 37 published formulas in the RUŌOD Lab Formula & Accord Library, including Agar Lantern, Ambrette Halo and Bitter Bridle. Each is listed with a link under "Used in formulas and accords" on this page.
Is Exaltolide covered by an IFRA Standard?
Yes. The IFRA Standards Library lists a Standard covering it: "Cyclopentadecanolide" — Restriction, 49th Amendment. The limits depend on the product category; read the Standard itself before formulating.
Sources
- PubChem — compound 235414, checked 19 October 2026.
- PubChem — GHS classification (the ECHA C&L Inventory notifications and any harmonised EU entry), read 26 October 2026.
- IFRA — Standards Library, read 19 October 2026.
- The Good Scents Company — Exaltolide (with Firmenich's description) — odour database.
- Scentspiracy — Exaltolide — distributor's description.
- US5266559 — unsaturated macrocyclic lactones (patent) — published literature.
- Olfactory profile: the RUŌOD Lab team's synthesis of the published descriptions above, reviewed 24 October 2026. Evidence: more than one published description. Classification and the short description: revision 1. Descriptions of odour are judgement, not measurement.