Reformulation is when a fragrance company changes the original formula of a scent. The public is not made aware of this. Usually but not always, after a reformulation the scent may become altered and or weakened.

Reformulations may happen because of ingredient recalls, or a change of manufacturer. Often after a reformulation the packaging may also undergo a change. It can be a new bottle style, or sometimes very subtle like a slight rewording or placement of text.

No, but those are the closest to a generic estimation across all brands. Each brand is slightly different and actually EACH PERFUME IS DIFFERENT DEPENDING ON THE YEAR OF RELEASE. Usually with a shared possible three year gap between the year I chose to highlight. 

Here's an example: I mention IFRA did a major reformulation in 2023. It was actually a mandate that was passed in 2020. However the reformulated bottles didn't start hitting stores until around 2023. *If it was a perfume or formula that already existed before the mandate was passed, a brand usually has up to two years to change the formula. *If it is a new release, the brand must follow the guidelines immediately.*Sometimes the reformulation can happen in the middle of year.*Also you have to factor in the time it takes for manufacturing, packaging, and shipping that can add more time until the reformulated perfume hits shelves. 

This can be costly for brands having to adhere to new guidelines. It can require new technology, new science and require getting rid of all prior equipment. This is why there's usually changes to the bottle, box, or manufacturer after a reformulation.

Have fun and enjoy your scent the journey! This is a deep dive section but I would generally say if you want a classic smelling perfume buy batches made before 2001, if you want semi-modern, fresh, salty, aromatic and aquatic smells buy batches before 2016, and if you like aroma chemicals (ambroxan amberwood and Iso-e-super) buy batches before 2023 for the best results!

**Note exact dates for reformulations may vary up to three years within the date I've listed depending on brand, or fragrance.(Per Ifra regulations)**

Probably not the only ingredient formulated this year, but the only well documented one, occured in 1983, and went into effect roughly around 1985. Musk ambrette was mainly being used as a replacement for deer musk at the time. It's actually derived from the hibiscus flower, with a sweet and musky smell to it. It reminds me of castoreum mixed with carnation, you could compare it to sarsaparilla, or an animalic type of root beer.

 A lot of very early animalic fragrances used this note, I believe Kouros and Antaeus both. This reformulation isn't well known, because castoreum and civet did a good job commonly replacing it after the reform.

This reformulation happened at the same time they introduced ingredient lists on boxes. "Alcohol, water, fragrance" . Also look for changes in bottle or manufacturer Ex: Charles of the Ritz Kouros bottles became "Parfums Corp" circa 1986. Also warnings on the box that the contents were flammable appeared around this time too. info about perfume being "flamable" also shows up around this time.

**Note exact dates for reformulations may vary up to three years within the date I've listed depending on brand, or fragrance.(Per Ifra regulations)**

Prior to 1993, our perfumes were crafted in conjunction with the use of raw materials without many restrictions.

However, this led to the depletion of sandalwood supplies, deforestation, and the endangerment of various animal species. In response, organizations such as PETA, in collaboration with IFRA, intervened to regulate the use of endangered natural ingredients used in perfumery, establishing a limit of 0.6% that took effect roughly in 1993.

As a result, Oakmoss heavy fragrances like Puig's Quorum experienced a slight reduction in potency, while others, such as Acqua Di Parma's Original Colonia, replaced certain musks or animalic notes with partial aldehydes to compensate for the changes. There were still great substitutes for these notes at this time, so this isn't a well known reform.

**This older group of colognes will usually have yellow, amber, or reddish hues to the liquid. You'll know if it's a post-1993 reformulation if the "green dot logo" circular arrows icon, is under the bottle or on the box.

**Note exact dates for reformulations may vary up to three years within the date I've listed depending on brand, or fragrance.(Per Ifra regulations)**

The appearance of long ingredient lists. 

(Major change) 2001-2004 - At this time computers and the internet began to transform our lives. Technology was advancing rapidly. Nutrition facts and ingredient lists were introduced on our food products. Perfume soon followed suit. To make fragrances more accessible for individuals with hyper-sensitive allergies ingredient lists were made mandatory on boxes . The use of raw materials were further reduced from 0.6%, to a 0.1% cap. 

The use of endangered and animal-derived notes also became prohibited.

 This is a reform that the timeline depended on the brand and or fragrance. Ralph Lauren/Cosmair, adapted their whole brand to the new changes almost immediately in 2001. Ifra offers a three year grace period to adhere to new mandates.

However most existing perfumes didn't adhere to the new mandate until 2004. You'll know if it's been reformulated if there's a long ingredient list on the box. 

Classic scent profiles that depended on raw materials like anamalics, fougeres, chypres and woody's took a drastic turn in terms of scent profile. (The classic smell) 

Afterwards, there became an uprise in the early 2000's aquatic freshies such as Chanel's Allure Homme edt and many more with they're use of aroma chemicals like calone. It Turned into sort of a fragrance revolution for this time period.

**You can recognize this post-2001 reformulation if there is a long detailed ingredient list on the box. 

**Note exact dates for reformulations may vary up to three years within the date I've listed depending on brand, or fragrance. (Per Ifra regulations)**

2011 - (IFRAs 43rd Amendment) required the removal of some organic compounds (notably atranol & chloroatranol) that had potential allergins attached to the raw materials they were associated with.

Afterwards, notes like jasmine and oakmoss were slightly altered in smell. However, there were still great substitutes for these notes at this time, so this isn't a well known reform.

*You can recognize this reformulation because after ingredients are diluted of their organic material, they don't age the same as ones that were. If you Look up vintage Versace Man Eau Fraiche, or even older Ck1 bottles, they will be a darker amber color. Bottles when the ingredients were modified or not included, the liquid will usually have little to no natural color.

**A source of information for my research came from Laurie, who was a perfumer between 2008 and 2014. She maintained a series of insightful blogs that offered a transparent and informative perspective on the fragrance industry. Her writings are still accessible on her website https://www.theartisaninsider.com/tag/ifra/.

**Note exact dates for reformulations may vary up to three years within the date I've listed depending on brand, or fragrance.(Per Ifra regulations)**

The changes implemented in mid-2016 significantly impacted numerous perfumes. As new regulations introduced restrictions and removals of several fixatives and compounds. This led to a noticeable decline in the depth and longevity of many fragrances.

Key ingredients such as Lilial, Limonene, Eugenol, Coumarin, and Citral were severely restricted and there was a complete removal of a compound known as Lyral. 

As a result of this change, well-known perfumes such as YSL's Nuit L'homme and Armani's Code EDT including numerous others experienced a noticeable decline in longevity and depth.

*You can recognize this reformulation because after this change most liquid in perfumes became more transparent. They would use a dye afterwards to change the color in most instances. You can date these perfumes easier in modern batch code websites.

**Note exact dates for reformulations may vary up to three years within the date I've listed depending on brand, or fragrance.(Per Ifra regulations)**

The 49th Amendment introduced a revised system for categorizing ingredients, leading to shorter ingredient lists (again) on product packaging.

The reformulated perfumes following IFRA's Amendment 49 began to emerge around 2023, featuring 22 notable ingredient removals. Among these, the most significant change was the restriction/removal of butylphenyl methylpropional, commonly referred to as lilial. This synthetic compound, which mimicked the scent of lily of the valley, also served as a fixative with aromatic properties.

Its widespread application in perfumery meant that its removal impacted the longevity and aromatics of numerous fragrances, including YSL's Y EDT, Versace's Pour Homme, PDM's Layton and Dior's Diorella, Gucci Guilty Absolute, etc to name a few.

**You can recognize this reformulation because the ingredient list on boxes became shorter again.**

**Note exact dates for reformulations may vary up to three years within the date I've listed depending on brand, or fragrance.(Per Ifra regulations)**

Created in August 2023 and taken into effect in 2025, amendment 51 introduced 48 new restrictions/eliminations of various synthetic aroma chemicals frequently used in fragrance.

Most notably new restrictions were placed on Iso-E-Super, Coumarin, Aldehydes, Limonene, Geraniol, Citronellol and the removal of Benzyl alcohol and Benzyl Salicylate.

As an example Iso-e-super is a widely used note in fragrances, such as terre d'hermes, Dior Homme 2021 and Hermes EAU Givree.

*You can recognize this recall if you have a shorter ingredient list on the box and check the batch code on a website.

• A Reddit user by the name of SarvGarg made an excellent easy to understand article about Amendment 51, I reposted it on my server here.

*It's important to note that some independent niche brands and middle eastern brands may not adhere to these changes immediately. However, if a brand is acquired by a larger corporation or they want to attain a stronger mainstream distribution, compliance with these guidelines may become necessary. Ex: both Tom Ford and Frederic Malle we purchased by Estee Lauder, etc.

It's not because it's a counterfeit bottle, it's just as official as any other bottle.

This was a primitive technique done by both stores and sometimes distribution, to camouflage the production date of items. 

Here's why, with examples:

1. Legally a store is given a certain amount of time, to be able to sell a fragrance until it was considered "expired". Stores sometimes would scratch the code off and sell off the rest of their stock without having to destroy the leftover "expired" items and lose profits.

2. Some stores would sell the "expired" fragrances in bulk, to independent buyers/resellers at discounted rates. The new seller would scratch the barcode off preserving that it wasn't for meant resale. Meaning basically if it came into a legal battle, they could say it was sold as a collectible item, and not meant for use on skin.

3. Some distributers would do this as well, heck sometimes they wouldn't even print a batch number on the box or bottle, Lancaster did it a lot. My theory is basically the same. As an example, lets say Lancaster produced 1000 bottles that were almost ready for distribution and IFRA said they had to reformulate and destroy every bottle that pre-dated a certain timeline. For a smaller manufacturer that couldn't afford to throw away hundreds of thousands of dollars away. They could still ship the rest of the orders to department stores without codes. I would imagine if they got in trouble, they could blame it on a machine error but it would be harder to prove they intentionally did anything against a new mandate.

If you find a vintage bottle with it's batch removed, you have to look at all of it's other distinguishing features to identify it's time line. In summery, vintage bottles with scratched off batch codes are the same exact products as bottles with a preserved batch code.

Enjoy the journey!

It varies by brand, but mostly yes.

An easy way to recognize newer batches vs older batches is the ingredient list on the box, example here.