In this article
The short answer
How long a skincare product lasts after opening is printed on the pack. Products with a shelf life over thirty months carry an open jar symbol with a number of months, the period after opening, typically 6M to 24M depending on the product type; products with a shorter shelf life carry a best before date instead. The period is set by the manufacturer from stability and preservation evidence and recorded in the product's safety report. As a rule of thumb, mascara and eye products last three to six months, water based creams and lotions six to twelve, sunscreens twelve, and oils, balms and solid products twelve to twenty four, and any product that changes in smell, colour or texture should be discarded whatever the symbol says.
Key takeaways
- The open jar symbol with a number and M is the period after opening, the manufacturer's statement of how long the product stays safe and effective once opened.
- Products that last under thirty months unopened carry a best before date with an hourglass symbol instead, and the date applies opened or not.
- The periods are decided from stability data, preservative efficacy and packaging, and written into the safety assessment; they are not guesses.
- Eye products are shortest because of infection risk; anhydrous products and airless packaging are longest.
- Smell, colour, texture and separation changes mean the product is finished regardless of the symbol.
- The same rules apply to every brand, so a product type table answers the question for any product you own.
Everyone has a jar at the back of the cupboard and no idea whether it is still good. The answer is on the jar, in a symbol most people have seen and few have decoded: a small open pot with a number and the letter M. Under Article 19 of Regulation (EC) No 1223/2009 and the UK regulation enforced through the Cosmetic Products Enforcement Regulations 2013, every cosmetic product must state either a best before date or a period after opening, and the choice between them follows a rule. Behind the symbol sits evidence: stability testing, preservative efficacy and the packaging, recorded in the product's safety assessment under guidance from the Scientific Committee on Consumer Safety. This evidence is exactly what a cosmetic product safety report captures as part of the cosmetic product safety assessment carried out under UK cosmetics regulation. So the question how long does this last after opening has a precise answer for every product, and a general answer for every product type.
This guide explains the two symbols and the thirty month rule that decides which appears, gives a table of typical periods after opening by product type so you can check anything in your bathroom, explains how manufacturers actually decide the period and why it differs between a mascara and a balm, lists the signs that a product has gone off regardless of the date, covers the questions people ask most about deodorant, hand soap, sunscreen and travel, explains what happens to a product before it is opened, and, for makers, describes how the period after opening is set in the safety assessment and what supports it. This kind of cosmetic product safety information is ultimately held in the Product Information File (PIF), which forms part of the regulatory compliance every brand needs to maintain. Then you can go and look at the jar.
What do the two symbols mean?
The open jar symbol, a small pot with its lid lifted and a number followed by M, is the period after opening: the number of months the product remains safe and fit for use once it has been opened for the first time. 12M means twelve months from opening. It appears on products whose unopened shelf life is more than thirty months. The hourglass symbol, or the words best before end, followed by a date is the date of minimum durability: the date until which the product, stored as directed, continues to do its job and remain safe. It appears on products whose unopened shelf life is thirty months or less, and it applies whether or not the product has been opened. A product carries one or the other, not both, and the choice is not the manufacturer's preference but a rule.
What is the thirty month rule?
If a cosmetic's minimum durability, the time it stays safe and effective unopened under normal storage, exceeds thirty months, the manufacturer does not have to print a date and instead prints the period after opening. If the durability is thirty months or less, the manufacturer must print a best before date and does not print a period after opening. The logic is that a long lasting product's risk arises from opening and use, so the symbol tells the consumer how long after opening it stays good, while a short lived product's risk arises from time itself, so the date is the limit regardless. Stable products such as oils, balms, solid perfumes and well preserved emulsions typically exceed thirty months and carry the symbol; products with sensitive actives, natural preservation or fragile emulsions may not and carry a date. Working out which applies to a given formulation is a routine part of UK CPSR preparation, since this detail must be confirmed and documented in the product information file before the product can be sold.
In practice
Symbol: count the months from the day you opened it. Date: the date is the limit, opened or not. If you cannot remember when you opened a product with a symbol, the signs of spoilage below are your guide.
Typical period after opening by product type
| Product type | Typical period after opening | Why | Signs it is finished |
|---|---|---|---|
| Mascara, liquid eyeliner | 3 to 6 months | Wand goes into the eye area and back into the tube; infection risk | Clumping, drying, any eye irritation |
| Eye cream, eye gel | 6 months | Applied near the eye; often lightly preserved | Change in smell or texture |
| Lip products | 12 months for sticks; 6 to 12 for glosses and balms in pots | Ingestion; fingers in pots | Waxy bloom, off smell, texture change |
| Face cream, moisturiser in a jar | 6 to 12 months | Water based; fingers introduce contamination | Smell, colour or texture change, separation |
| Face cream in an airless pump or tube | 12 months | Water based but protected from contamination | As above |
| Serum, toner, water based treatment | 6 to 12 months | Water based; actives can degrade | Colour change, especially vitamin C turning orange |
| Body lotion, hand cream | 12 months | Water based, larger pack, frequent use | Smell, separation |
| Body wash, shampoo, conditioner | 12 months | Rinse off, well preserved, used quickly | Separation, smell, thinning |
| Liquid hand soap | 12 months | As body wash | As above |
| Cleansing balm, oil cleanser | 12 months | Anhydrous but fingers in jar | Rancid smell |
| Facial oil, body oil | 6 to 12 months | Oxidation of oils, especially polyunsaturated | Rancid, crayon like smell |
| Balms, salves, butters | 12 to 24 months | Anhydrous, stable | Rancid smell, grainy texture |
| Solid perfume, perfume oil | 12 to 24 months | Anhydrous, stable carrier | Scent drift, rancid note |
| Alcohol perfume | 24 to 36 months or a date | Self preserving; some notes fade | Scent change, darkening |
| Sunscreen | 12 months | Filters and emulsions degrade; protection may fall | Separation, thinning, change in smell; discard after a season in heat |
| Deodorant, antiperspirant | 12 months | Applied to sensitive skin; sticks are stable | Change in smell or texture |
| Powder makeup, pressed and loose | 12 to 24 months | Dry; stable | Hard film on pressed powder, off smell |
| Liquid foundation | 6 to 12 months | Water based emulsion | Separation, colour change |
| Nail polish | 12 to 24 months | Solvent based | Thickening, separation |
| Bath bombs, bath salts | 6 to 12 months | Absorb moisture; fragrance fades | Crumbling, fizz loss, fading scent |
These are typical ranges, not rules; the number on the pack is the one that applies to the product in your hand, and it can be shorter or longer than the table for good reasons. A brand with excellent stability data and airless packaging may print 24M on a cream; a natural brand with a gentle preservative may print 6M on the same type of product. Both are correct for their product.
How do manufacturers decide the period after opening?
From evidence, recorded in the Cosmetic Product Safety Report. Stability testing shows how long the product keeps its appearance, texture, pH and performance under normal and accelerated storage. Preservative efficacy testing, the challenge test, shows that the preservative system controls microbes introduced in use, and its result over time supports a period during which contamination is controlled. Packaging is considered: an airless pump keeps fingers and air out and supports a longer period than a jar; a wide mouthed pot in a bathroom supports a shorter one. The product type and its use sets a ceiling: eye area products are kept short whatever the data because of infection risk. The safety assessor reviews all of this in Part A of the report and confirms or adjusts the period in Part B, and the manufacturer prints what the report supports. How long does a product's period after opening last is therefore never a guess; it is a figure a qualified safety assessor has derived from the toxicological profile and stability evidence on file, confirming the product is safe for human use under Regulation (EC) No 1223/2009 and the equivalent rules applied across the EU and UK market. A period after opening is therefore a statement backed by a file, and a brand asked to justify it should be able to point to the stability and challenge test reports, the same file a Responsible Person in the United Kingdom (UK) or elsewhere must hold as part of the mandatory safety assessment. Our label review guide explains the labelling side.
What are the signs a product has gone off, whatever the symbol says?
- Smell. A rancid, crayon like or sour note in an oil, balm or cream; a changed or faded scent in a perfume.
- Colour. Darkening, yellowing, or the orange turn of an oxidised vitamin C serum.
- Texture. Graininess in a butter, thinning or thickening in a lotion, drying in a mascara.
- Separation. An emulsion that has split into layers and does not re mix.
- Mould or specks. Visible growth, often in the bottom of a jar or around the rim.
- Reaction. Stinging, redness or itching from a product that was previously fine.
- Performance. A sunscreen that feels thin, a cleanser that no longer foams, a deodorant that no longer works.
Any one of these means the product is finished, even if the symbol says six months remain. The symbol is a maximum under normal storage, not a guarantee against a hot bathroom, a wet finger or a lid left off.
Ask yourself
Take the oldest product in your bathroom, find the symbol, and try to remember when you opened it. If you cannot, smell it and look at it. Then decide whether the price of a new one is worth the risk of the old one on your face.
For makers: how the period after opening is set and supported
The period after opening is a labelling element you must print and a claim the safety assessor must support. Part A of the CPSR records the stability data you hold, the preservative system and its challenge test result, the packaging and the intended use; Part B confirms the period the evidence supports or sets a shorter one, and often ties it to a pH range or a packaging condition. Without stability data the assessor will support only a conservative period; with accelerated and real time stability and a passed challenge test, a longer one. A maker who prints 24M on a jar cream with no stability data has printed a number the file cannot defend, and a maker whose product exceeds thirty months unopened must use the symbol, not a date. Our guides to water activity and preservation and pH explain two of the factors that decide it, and Phoenix's CPSR records the reasoning so the number on your label is one you can show.
The jar at the back of the cupboard has been telling you the answer all along. Now you can read it.
Myths we hear
- Cosmetics do not really expire. They do, and the pack tells you when.
- The symbol is the same as a best before date. One counts from opening; the other is a fixed date.
- If it looks fine it is fine. Sunscreen protection and preservative efficacy fall invisibly.
- Natural products last longer because they have no chemicals. Natural oils oxidise faster and gentle preservatives support shorter periods.
- Topping up a pump with water stretches it. It unpreserves it.
What to do this week
- Write the opening date on every product you open with a marker.
- Check the symbol on the products you use daily.
- Discard anything with a changed smell, colour or texture.
- Replace last summer's sunscreen.
- If you make products, check that the number on your label is the one in your CPSR.
Frequently asked questions
What does the open jar symbol with a number mean?
It is the period after opening: the number of months the product remains safe and fit for use after it is first opened. 12M means twelve months from opening. It appears on products whose unopened shelf life exceeds thirty months.
What is the difference between the open jar symbol and a best before date?
The open jar symbol counts months from opening and appears on products lasting over thirty months unopened. A best before date, shown with an hourglass, is a fixed date that applies whether or not the product is opened, and appears on products lasting thirty months or less.
How long does moisturiser last after opening?
Typically six to twelve months for a water based cream in a jar, and around twelve months in an airless pump or tube. The number printed on your product is the one that applies; discard sooner if smell, colour or texture changes.
How long does mascara last after opening?
Three to six months. The wand goes near the eye and back into the tube, so infection risk keeps the period short, and any eye irritation means it is finished.
Does sunscreen expire?
Yes. Sunscreens typically carry a twelve month period after opening and often a best before date, because UV filters and emulsions degrade and protection falls invisibly. Discard a sunscreen that has spent a summer in heat regardless of the symbol.
How do manufacturers decide the period after opening?
From stability testing, preservative efficacy testing and the packaging, reviewed by a safety assessor in the Cosmetic Product Safety Report, with product type setting a ceiling for eye area and similar products. The number printed is the one the evidence supports.
What are the signs a cosmetic has gone off?
A rancid or changed smell, darkening or colour change, graininess or thinning, separation that does not re mix, visible mould or specks, a reaction from a product that was previously fine, or loss of performance such as a sunscreen feeling thin.
How long do products last before opening?
Products with a period after opening last more than thirty months unopened under normal storage; products with a best before date last until that date. Cool, dark, dry storage extends both.
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