Why Do Perfumes Get Reformulated? The Real Reasons Your Favourite Smells Different

If you have worn the same perfume for ten years, there is a good chance the bottle you buy today is not the same liquid as the bottle you bought then. This is one of the most common complaints in fragrance, and it is usually explained in one word: cost-cutting. That explanation is occasionally right and mostly wrong. Here is what actually rewrites a formula.

What does "reformulation" mean?

Reformulation is a change to the recipe of a perfume that is still sold under the same name. The bottle, the box and the marketing stay put; the contents are adjusted. It can be a single ingredient swapped for a substitute, a natural extract reduced to a permitted level, or — rarely — a wholesale rebuild.

Reformulation is not the same thing as a perfume ageing in your cupboard, and it is not the same thing as a flanker (a new fragrance released under an existing name, like "Intense" or "Elixir" versions). Those are three different reasons a bottle can smell unfamiliar, and they get confused constantly.

Reason 1: Safety standards moved

This is the biggest one, and it is not optional.

The fragrance industry runs a self-regulatory safety system through the International Fragrance Association (IFRA), whose IFRA Standards ban, restrict or set conditions on specific fragrance materials, based on safety assessments. The Standards are updated in numbered Amendments, and each Amendment comes with deadlines by which perfumes must comply.

The current one is the 51st Amendment, notified by IFRA on 30 June 2023. According to compliance summaries from UL Solutions, its deadlines for existing perfumes already on the market ran to 30 July 2024 for outright prohibitions and 30 October 2025 for restrictions — which means a large number of perfumes on shelves right now were quietly rewritten in the last two years. The 52nd Amendment is already in progress: IFRA's public consultation closed on 12 June 2026 and formal notification is expected around the end of November 2026.

Separately from IFRA, EU law bans materials outright. Commission Regulation (EU) 2017/1410 added three substances to the list of substances prohibited in cosmetics: HICC (often sold as Lyral, a lily-of-the-valley type material used very widely), plus atranol and chloroatranol. Products containing them could not be placed on the EU market after 23 August 2019, and could not be sold at all after 23 August 2021.

That single regulation is responsible for a great many "they ruined it" complaints, because HICC was in an enormous number of well-known fragrances. The EU banned all three on the advice of its Scientific Committee on Consumer Safety, which had identified them as the fragrance allergens responsible for the highest number of contact allergy cases.

One detail in that regulation is worth quoting, because it shows the regulator was not naive about what it was asking for. The reason the deadlines were set so far out, it says, is "the exceptionally complex and lengthy procedure for fragrance reformulation and consumers' concerns over the change of the olfactory properties of fragrances". In other words: the EU knew perfectly well that people would notice, and that rewriting a formula is difficult work.

The oakmoss misunderstanding

Atranol and chloroatranol are worth understanding properly, because the internet gets this wrong.

They are not fragrance ingredients that perfumers were adding. They are constituents that **occur naturally in oakmoss (Evernia prunastri) and treemoss extracts** — the materials that give a classic chypre its damp, forest-floor darkness. IFRA restricts them to a maximum of 100 ppm within those moss extracts.

So oakmoss was never banned. What happened is that the moss extracts had to be processed to strip those two constituents out. "Depleted" oakmoss is still legal and still used. It simply does not smell identical to the untreated extract that older formulas were built on — which is why perfumes from the classic chypre family are the ones people most often say have changed.

Reason 2: The raw material changed, or stopped arriving

Perfumery depends on agriculture, and agriculture has bad years.

• Harvests fail. A frost, a drought or a bad season in one growing region can move the price and the quality of a natural extract sharply, and there is no substitute field to go to.
• Trade rules tighten. Some materials are governed by international conservation controls; agarwood (oud) and certain rosewoods are the well-known examples. Supply becomes slower, more documented and more expensive.
• Suppliers discontinue things. A synthetic aroma molecule is a manufactured product like any other. If the company that makes it stops making it, every perfume containing it needs a new solution, regardless of how famous the perfume is.

None of this involves anyone deciding to make a perfume worse. It involves a perfumer being told that a material they built a structure on is no longer available in the quality or quantity required.

Reason 3: The perfume changed hands

Brands get sold. Licences move between the big fragrance groups. When that happens, production often moves too — to a different fragrance house, a different factory, sometimes a different supplier for the same nominal ingredient.

Even with the formula on paper unchanged, the same recipe made from a different supplier's version of an ingredient will not be bit-for-bit identical. Naturals in particular vary by origin and by year.

Reason 4: Cost — sometimes

Cost-cutting does happen, and pretending otherwise would be dishonest. A high-volume fragrance under pressure to hold a price point while raw material costs rise can end up with cheaper substitutes and a thinner structure.

But note where it usually shows up: in very large-volume fragrances with a fixed shelf price. It is a much weaker explanation for a small independent release, where the volumes are too small for ingredient savings to matter and the reputational cost of being caught is enormous.

How can you tell whether your perfume has been reformulated?

Honestly? It is harder than the internet suggests, and the first thing to rule out is yourself.

Things that change that are not the formula:

• Your nose. Olfactory adaptation to a scent you wear daily is real; so is the way your sense of smell shifts with age, illness and medication.
• Your skin and your environment. Temperature, humidity and skin condition all change how a fragrance performs. We wrote about the summer version of this in why perfume smells stronger in summer.
• Your old bottle. A partly used bottle stored in a warm bathroom for six years has oxidised. You may be comparing fresh juice against a degraded reference, not against the original. See how to store perfume so it lasts.

Things that are genuine evidence:

• The batch code, usually printed or stamped on the bottom of the box and the base of the bottle. It identifies the production run. It is the only hard data most buyers have.
• The ingredient list on the box. Regulated allergen declarations are printed there, and they follow the formula. If a material has been removed or reduced below the declaration threshold, the list changes. The EU has just expanded that list considerably — we covered that in the new EU fragrance allergen labelling — which will make lists longer without anything in the bottle changing at all. Read them side by side with that in mind.
• A side-by-side sniff, on paper strips, at the same time, in the same room. Not memory. Memory is not evidence.

Here's how we approach it at SHŌ ITO

We are a new house, which puts us in an unusual position on this subject: we have nothing to reformulate.

That has practical consequences we think are worth stating plainly.

We are formulating to today's rules from the start. Our first perfume is being developed under the standards and the labelling requirements that are in force now, rather than being an older formula edited down to fit them. There is no legacy version of it that someone will one day compare us unfavourably against.

We keep the paperwork. Safety documentation, ingredient declarations and batch records are kept per production run, which is both a legal requirement in the EU and the only way anyone can answer the question "did this change?" with a fact rather than an opinion.

If we ever have to change something, we will say so. The reason reformulation has such a bad reputation is not really that formulas change — they always have. It is that they change silently, and people are told they are imagining it. We would rather publish the reason.

In short

Perfumes get reformulated because safety standards are revised on a schedule, because agricultural materials are not guaranteed, because brands change owners, and — sometimes — because of cost. The first three account for most of it.

If a perfume you love smells different, check the batch code and the ingredient list before you check your assumptions. And be honest about the six-year-old bottle on the shelf.

If you would like the occasional considered piece on how perfume actually gets made and regulated, our newsletter goes out on Sundays.