Last updated: May 2026 · Written by Katie Johnson, founder of The Fragrance World
Iso E Super® is an IFF-owned synthetic perfumery molecule (IUPAC: 1-(octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)ethan-1-one · molecular formula C16H26O · molecular weight 234.4 g/mol · CAS 54464-57-2) invented in 1973 by chemists John B. Hall and James M. Sanders at International Flavors & Fragrances. It smells of soft cedar-amber with a velvety, slightly smoky, almost transparent quality · but its signature property is the “second skin” effect: at high dose, the molecule reads as the wearer’s own skin scent rather than as a perfume. Iso E Super is the molecule behind Escentric Molecules Molecule 01 (which is 100% Iso E Super), Hermès Terre d’Hermès, Lancôme Trésor, Halston Z-14 and roughly 50% of modern niche fragrances. It is, by industry estimates, the most-used woody synthetic in perfumery.
TFW perspective: Iso E Super is in the base of most of our 74 EDPs at a small dose for skin-blend and projection-extension purposes · but the fragrances where you can actually smell it as a hero character are Five Forty (where Iso E Super carries the Cetalox-saffron heart for 12+ hours) and the discreet woody dry-downs of Halfeti Charm and Layton. When customers say “this smells like me, only better” · what they are responding to is the Iso E Super second-skin character.
What Iso E Super smells like
Iso E Super is one of the most evasive smells in commercial perfumery · in part because it tends to read as a texture more than as a specific note. The closest descriptors are:
- Soft cedar wood · woody, dry, slightly smoky, without the sharpness of pencil-shaving cedar
- Velvety amber · warm, plush, slightly powdery, the “velour” character that defined late-90s and 2000s masculines
- Transparent skin warmth · clean, almost unsweet, with a faint vetiver lift
- A faint suede or chamois quality · soft, slightly animalic, but quietly
- The smell of the second hour of a fragrance · the molecule emerges 30-60 minutes after spraying and dominates the dry-down
The molecule has an extraordinarily low odour threshold for its weight class. A perfumer can use it at very high dosage (Molecule 01 is 100% Iso E Super; many niche fragrances use 25-50% of the concentrate as Iso E Super) without the fragrance reading as “loud” · the molecule simply makes everything around it appear softer, warmer and more skin-melded.
The chemistry · molecular structure, weight, isomers
The bare facts:
| Property | Value |
|---|---|
| IUPAC name | 1-(octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)ethan-1-one |
| CAS number | 54464-57-2 |
| Molecular formula | C16H26O |
| Molecular weight | 234.4 g/mol |
| Structure | Octahydronaphthalene with a methyl ketone substituent |
| Appearance | Colourless to pale-yellow oily liquid |
| First synthesised | 1973, IFF (John B. Hall & James M. Sanders) |
| First trade name | Isocyclemone E |
| Modern trade name | Iso E Super® (refined version, 1975) |
Iso E Super is technically a mixture of stereoisomers · the original IFF process produces several different molecular geometries that all share the same basic skeleton. The “high isomer” form is more aromatically intense than the base mixture and is sold separately as Iso Gamma (or Iso E Super Plus). The Iso Gamma isomer is what’s used at 100% in Escentric Molecules Molecule 01 specifically.
Common alternative trade names you’ll see on materials suppliers’ lists for the same broad molecule: OTNE (octahydrotetramethyl acetonaphthone), Anthamber, Amber Fleur, Boisvelone, Iso Ambois, Amberlan, Iso Velvetone, Orbitone, Amberonne. These are not all literally identical · some are competitor synthesis routes with slight isomer ratio differences · but for consumer purposes they read as Iso E Super.
At 234.4 g/mol, Iso E Super sits in the same low-volatility weight class as ambroxan (236.4) and Cetalox (236.4). All three are heavy by perfumery standards and all three function as base-note fixatives that extend wear time to 8-14 hours on skin.
The “second skin” effect explained
The single most discussed property of Iso E Super in perfumery circles is its second-skin character · the molecule’s tendency to read as the wearer’s own skin scent rather than as an applied perfume.
Three things produce the effect:
- Low odour threshold combined with high volume tolerance. A perfumer can use Iso E Super at 50-100% of the concentrate without the fragrance smelling “heavy”. The molecule doesn’t fatigue the nose the way a heavily musk-loaded composition does.
- Anosmia and re-perception. Roughly 20% of people are partially anosmic to Iso E Super · they perceive it at normal concentrations but lose the perception during wear (the brain adapts within minutes). The wearer therefore stops smelling their own fragrance while everyone around them continues to smell it. This produces the “smells like nothing on me but everyone keeps complimenting me” experience.
- Skin-warm character. Iso E Super’s smell profile (soft cedar-amber-velvet) is genuinely close to the warm, slightly woody character of clean human skin. So the molecule doesn’t replace skin smell · it blends with and amplifies it.
The combined effect is that Iso E Super-led fragrances · particularly Molecule 01, but also Terre d’Hermès, Le Labo Santal 33, Maison Margiela Replica Lazy Sunday Morning · don’t smell like perfume. They smell like an idealised version of the wearer. This is the entire commercial pitch of the modern “skin scent” niche category.
John Hall, IFF and the 1973 discovery
Iso E Super was discovered in 1973 by chemists John B. Hall and James M. Sanders at International Flavors & Fragrances (IFF) · then and now one of the four major fragrance houses (alongside Givaudan, Firmenich, and Symrise).
The initial patent was for “Isocyclemone E”, a captive woody-amber molecule positioned as an alternative to natural cedarwood. The first commercial use was modest · Hall and Sanders had identified a useful new molecule but hadn’t yet realised its second-skin character. Refinement of the synthesis method in 1975 produced a purer, more consistent grade · the molecule renamed and trademarked as Iso E Super®.
The breakthrough commercial moment was Hermès Bel Ami (1986) and Lancôme Trésor (1990), which used Iso E Super in significant doses in their bases. By the early 2000s, Iso E Super was a captive standard in IFF perfumers’ palettes and was filtering into competitor houses’ work via the materials-supply market.
The molecule’s status as a counter-cultural cult ingredient came later, with Geza Schoen’s Escentric Molecules launch in 2006 (see next section).
Molecule 01 and the Geza Schoen story
In 2006, German-born perfumer Geza Schoen launched Escentric Molecules with a single fragrance: Molecule 01, which contains exactly one ingredient · the Iso Gamma isomer of Iso E Super · at 100% concentration in a carrier alcohol. No top notes, no heart notes, no other base materials. Just one synthetic molecule, sprayed straight onto skin.
The pitch was deliberately conceptual: Schoen wanted to demonstrate that a single synthetic, treated as the entire composition rather than a supporting note, could read as a complete fragrance. The bet was that Iso E Super’s second-skin character would make Molecule 01 work as a “your skin but better” perfume despite having no traditional pyramid structure.
Molecule 01 sold modestly for the first few years and then went viral on social media in the late 2010s. It became one of the most-talked-about niche fragrances of the decade · partly for the second-skin effect, partly for the conceptual purity, partly because it costs roughly £80 / 100ml versus £200-£400 for comparable niche releases.
Schoen subsequently launched Molecule 02 (Ambroxan), Molecule 03 (Vetiveryl Acetate), Molecule 04 (Javanol) and Molecule 05 (Cashmeran) · all single-ingredient fragrances using different captive synthetics. The series demonstrated that the second-skin character isn’t unique to Iso E Super, but Iso E Super remains the cleanest and most commercially successful example.
The Molecule 01 commercial success is why Iso E Super is now arguably the most-recognised synthetic perfumery material by name among engaged consumers · more than ambroxan, more than Cetalox, more than Galaxolide.
Famous perfumes that feature Iso E Super
Iso E Super shows up in an estimated 50% of all niche fragrances launched since 2010 and a meaningful share of mainstream fine fragrance back to the early 1990s. The roll-call (verified via Fragrantica and perfumer interviews):
- Escentric Molecules Molecule 01 (2006) · 100% Iso Gamma. The reference fragrance for the molecule.
- Hermès Terre d’Hermès (2006) · perfumer Jean-Claude Ellena. Heavy Iso E Super in the cedar-vetiver dry-down. One of the most commercially successful masculines of the last 20 years.
- Lancôme Trésor (1990) · among the earliest commercial overdose uses. The molecule is much of what gives Trésor its powdery rose-amber dry-down.
- Hermès Bel Ami (1986) · the 1986 launch that demonstrated Iso E Super’s potential as a hero base material.
- Halston Z-14 (1976) · among the very first commercial uses, soon after the IFF refinement.
- Maison Francis Kurkdjian Baccarat Rouge 540 (2015) · Iso E Super carrying the Cetalox-and-saffron heart. Critical to the 12-14 hour wear time.
- Le Labo Santal 33 (2011) · heavy Iso E Super under sandalwood and leather.
- Maison Margiela Replica Lazy Sunday Morning (2011) · Iso E Super in the skin-melded musk-iris base.
- Diptyque Eau Capitale (2019) · Iso E Super under rose and patchouli.
If a contemporary niche or premium-mainstream fragrance is described as “transparent”, “skin scent”, “your skin but better”, “soft and woody” or has a notably plush dry-down, the bet is Iso E Super in the base · usually at significant dose.
TFW fragrances that use Iso E Super
Iso E Super appears in the base of most of our 74 EDPs as a small-dose skin-blend material · the same way it appears in the base of most modern fragrances. The picks where it does meaningful aromatic work are:
Five Forty · Inspired by MFK Baccarat Rouge 540 · 12-14 hr wear
Iso E Super carries the Cetalox-and-saffron heart through the 12+ hour dry-down. Without the molecule, Five Forty would tap out at 6-8 hours. With it, the fragrance wears into the next day. Saffron and jasmine sit on top of the Iso E Super-and-Cetalox base.
Halfeti Charm · Inspired by Penhaligon’s Halfeti · 10-14 hr wear
Iso E Super sits in the resin base under oud, Bulgarian rose and tonka. The molecule’s soft cedar-amber character extends the heavy resin dry-down past 10 hours and gives the fragrance its plush, niche-feeling skin sillage.
Buy TFW Halfeti Charm · £29.95
Layton · Inspired by PDM Layton · 10-12 hr wear
Iso E Super in the vanilla-guaiac-sandalwood dry-down. The original PDM Layton uses Iso E Super at a relatively high dose to give the lavender-cardamom heart its cool, woody, skin-melded base · we hold the same architecture.
For a fuller breakdown of the woody-amber category across our range, see our long-lasting perfumes UK guide and best ambroxan perfumes UK 2026 (many ambroxan-led fragrances also use Iso E Super as a complementary base material).
Iso E Super vs Ambroxan vs Cetalox
The three workhorse base-note fixatives of modern perfumery, all sitting in the same low-volatility ~234-236 g/mol weight class:
| Iso E Super | Ambroxan | Cetalox | |
|---|---|---|---|
| Molecular weight | 234.4 g/mol | 236.4 g/mol | 236.4 g/mol |
| Owner / supplier | IFF | Henkel / Kao | Firmenich |
| Year invented | 1973 | 1950 | 1990s (trade name) |
| Smell | Soft cedar-amber, velvety | Dry, mineral, salt-radiant | Warm, creamy, musk-adjacent |
| Signature effect | Second-skin / sillage amplifier | Radiant masculine fresh | Plush niche-floral warmth |
| Iconic example | Molecule 01 / Terre d’Hermès | Dior Sauvage | Baccarat Rouge 540 |
| Use rate in modern niche | ~50% | ~60% | ~30-40% |
In practice, most modern niche compositions use all three together · Iso E Super for the second-skin amplifier and dry-down length, Ambroxan or Cetalox for the radiant/creamy ambergris warmth, plus a Galaxolide or Helvetolide white musk for the additional fixation. Baccarat Rouge 540 is the textbook example: Cetalox + Iso E Super + saffron + jasmine + amberwood. Full breakdown at What Is Ambroxan? and What Is Cetalox?.
Is Iso E Super safe? IFRA limits and anosmia
Iso E Super is well-studied and generally well-tolerated. The International Fragrance Association (IFRA) does not impose a strict use-restriction on the molecule for fine fragrance · it is approved at the high doses typical of modern perfumery (up to 100% of the concentrate in the Molecule 01 case). The molecule is not classified as a skin sensitiser, photoxic, or developmental toxin at consumer dose levels.
The most common “issue” is anosmia · roughly 20% of the population is partially or fully unable to smell Iso E Super, and many people who can smell it initially adapt to the smell within minutes of wear (which is what produces the “I can’t smell my own perfume” experience). This is the same broad genetic mechanism that affects ambroxan perception. If you have tried Molecule 01 and felt nothing on yourself while others complimented you, Iso E Super anosmia is the cause.
A very small subset of users find very-high-dose Iso E Super fragrances headache-inducing at close range. This is dose-related and typically resolves by switching to a lower-dose composition rather than indicating a true allergy.
FAQ
What is Iso E Super? Iso E Super is a synthetic perfumery molecule (C16H26O, 234.4 g/mol) invented in 1973 by John Hall and James Sanders at International Flavors & Fragrances (IFF). It smells of soft cedar-amber with a velvety, transparent quality and is famous for the “second-skin” effect · the molecule reads as the wearer’s own skin scent rather than as an applied perfume. It is the single ingredient in Escentric Molecules Molecule 01.
What does Iso E Super smell like? Iso E Super smells of soft cedar wood, velvety amber and a transparent skin warmth · with a faint suede quality. It is one of the most evasive smells in perfumery because it tends to read as a texture (plush, velour, second-skin) rather than as a specific identifiable note. The molecule emerges in the dry-down (30-60 minutes after spraying) and dominates the 8-14 hour wear arc.
What is the “second skin” effect? The second-skin effect is Iso E Super’s tendency to read as the wearer’s own skin scent rather than as an applied perfume. Three things produce it: low odour threshold combined with high volume tolerance (the molecule doesn’t smell “loud” even at very high dose), partial anosmia (~20% of people lose perception during wear while everyone else continues to smell it), and the molecule’s genuine similarity to the warm woody character of clean human skin.
Is Iso E Super used in Molecule 01? Yes · Molecule 01 (Escentric Molecules, 2006) is 100% Iso Gamma (the high-isomer form of Iso E Super) in a carrier alcohol. There are no other ingredients, no top notes, no heart, no other base materials. The fragrance was launched by perfumer Geza Schoen to demonstrate that a single synthetic molecule could function as a complete perfume.
Is Iso E Super the same as ambroxan? No, but they are similar in function. Both are heavy (~234-236 g/mol) low-volatility base-note fixatives that extend fragrance wear time to 8-14 hours. The smell difference: ambroxan reads dry, mineral and salt-radiant; Iso E Super reads soft, cedar-amber and velvety. Most modern niche compositions use both together. Full breakdown at What Is Ambroxan?.
Is Iso E Super vegan? Yes. Iso E Super is a fully synthetic molecule produced from petrochemical precursors via the original IFF synthesis route. No animal source is involved at any stage.
Why does Iso E Super make perfume last longer? Because at 234.4 g/mol the molecule is among the slowest-evaporating common perfumery materials. It wears 8-14 hours on skin and physically slows the evaporation of lighter notes (citrus, florals) above it. Fragrances with significant Iso E Super dose typically wear 4-6 hours longer than the same composition without it. Full breakdown at long-lasting perfumes UK guide.
What perfume has the most Iso E Super? Escentric Molecules Molecule 01 (2006) is 100% Iso Gamma · the entire fragrance is just Iso E Super. Among traditional pyramidal fragrances, Hermès Terre d’Hermès, Le Labo Santal 33, Maison Francis Kurkdjian Baccarat Rouge 540 and Diptyque Eau Capitale are among the most Iso E Super-loaded mainstream releases on the market.
Why can’t I smell Iso E Super on myself? Roughly 20% of people are partially anosmic to Iso E Super, and even those who can smell it tend to adapt during wear · the brain stops perceiving the molecule within minutes. This is why Iso E Super-led fragrances famously “smell like nothing on me but everyone keeps complimenting me”. The fragrance is still projecting; you have just adapted to your own scent.
Where can I try Iso E Super-led fragrances? The TFW discovery set lets you sample five fragrances at 5ml each before committing to a full 50ml bottle. Five Forty is the clearest Iso E Super showcase in our range (carrying the Cetalox-saffron heart through 12+ hour wear). Halfeti Charm and Layton both use Iso E Super in the dry-down. £14.99 for the set, redeemable against any full-size purchase.
Sources & references
This article draws on IFF’s product reference data for Iso E Super®, the original Hall & Sanders patent (1973) for Isocyclemone E, the Wikipedia entry for tetramethyl acetyloctahydronaphthalenes, Fragrantica’s note pyramids for the cited commercial fragrances, the Good Scents Company chemistry database for IUPAC names and CAS numbers, Geza Schoen’s published interviews on the Escentric Molecules launch, perfumery reference works (Perfumes: The A-Z Guide by Luca Turin & Tania Sanchez), Luca Turin’s writing on Iso E Super in The Secret of Scent, and The Fragrance World’s own Q1 2026 wear-time panel testing. Specific molecular weights, CAS numbers and historical synthesis facts have been cross-referenced against manufacturer and peer-reviewed sources; please verify against the original source before reuse.
Browse the Iso E Super range
Five Forty · Halfeti Charm · Layton · Discovery set · Related: What Is Ambroxan? · What Is Cetalox?
All £29.95 for 50ml. Free UK delivery over £50. 14-day no-quibble returns. Made in Liverpool by The Fragrance World.
