Perfumes are reformulated — their formulas changed after launch — mainly for four reasons: safety standards and regulation restrict or ban a material; a natural material becomes scarce, protected or too costly; a supplier or material is discontinued; or the house makes a commercial decision, such as changing cost or style. A reformulated perfume may be almost identical or noticeably different. Houses rarely announce reformulations, which is why many people first notice them as "my perfume smells different".

Safety standards and regulation

The most frequently cited reason. The International Fragrance Association (IFRA) publishes standards that restrict or prohibit certain materials in products applied to skin, based on safety assessments of risks such as skin sensitisation. Many fragrance makers follow them, and cosmetics laws in many markets add their own rules. When a standard tightens, perfumes using that material above the new limit must be changed.

Well-known examples include:

  • Oakmoss, central to chypres, now strictly limited, and used in treated forms with certain components reduced. See What Is a Chypre Perfume?.
  • Certain citrus components that make skin react to sunlight. See Bergamot in Perfume.
  • Some older synthetic musks and other materials no longer considered acceptable. See What Is Musk in Perfume?.
  • Some natural materials that contain restricted substances, limiting how much can be used.

Scarcity, protection and cost

Natural materials depend on harvests, weather, land and, sometimes, protected species. Sandalwood from India, natural musk and certain resins have become scarce or tightly controlled over the years, and natural oils can change price sharply after poor harvests. A house may replace or reduce a material it can no longer obtain consistently. See The Quiet Influence of Sandalwood and Oud, and the Many Lives of a Material.

Supply and discontinued materials

Sometimes a single material — often a particular synthetic or a specific grade of natural oil — simply stops being made, or a supplier changes it. The perfumer must find a substitute that behaves the same way in the formula, which is rarely perfect.

Commercial decisions

Houses may also revise perfumes to reduce cost, to update a style for a new audience, or to suit production in a different place. These reformulations are the least visible and the most debated.

A perfume is a formula, and a formula lives in a world of harvests, laws and suppliers. It is remarkable that so many stay as close to themselves as they do.

How reformulation is done

The perfumer replaces or reduces the affected material and rebalances everything around it, then compares the new version with a reference sample of the old over many trials, aiming to match it as closely as possible. Success varies: some changes are imperceptible, others alter a perfume’s character. See What Does a Perfumer Do?.

Reformulation, flankers and versions

A reformulation keeps the perfume’s name and replaces the old formula. That is different from a flanker — a new perfume sold under a variation of an existing name — and from different concentrations of the same name, which may be composed differently by design. See Eau de Parfum vs Eau de Toilette.

What it means for you

  • Your favourite may change. If a new bottle smells different, reformulation is one possible cause among several; work through the others first. See Why Does My Perfume Smell Different Now?.
  • Older bottles aren’t automatically better. They may have aged; see Does Perfume Expire?.
  • Reformulation is often a safety improvement, even if the result is less like the original.

Common questions

How can I tell if a perfume has been reformulated?

Compare an older bottle with a new one side by side, and look for consistent reports from other long-time wearers. Houses rarely confirm reformulations publicly.

Is it legal to change a perfume without saying so?

Generally, yes, provided the label meets labelling rules for the new formula.

Are reformulated perfumes worse?

Not necessarily. Some are almost identical; some differ noticeably; opinions of the differences vary.

Further reading

For the standards behind many reformulations, RUŌOD Lab’s IFRA Standards Explained sets out how they work for brands and perfumers, and its How to Adjust a Perfume Formula describes how a perfumer rebalances a formula when a material changes.