Detergents or surfactants (e.g., lauryl sulfates, sulfosuccinates, soapwort, agave) Conditioners (e.g., hydrolyzed silk, dimethicone) Thickeners (e.g., sodium chloride, PEG 150) Preservatives (e.g., sodium benzoate, parabens, DMDM hydantoin) Special additives (e.g., vitamins, tea tree oil, beer) Fragrances (e.g., essential oils, rose water) Sequestering agents (e.g., polyphosphates, EDTA) Opacifiers (e.g., glycol distearate) pH adjusters (e.g., glycolic acid, citric acid) Active cleansing agents (only in medicated shampoos) (e.g., tar derivatives, salicylic acid, selenium sulfide)
Almost all of the ingredients are stable chemical or biochemical derivatives. However, certain ingredients may have a limited shelf life and thereby affect the shampoos activity. Ketoconazole, an active component of antifungal shampoos, is one such ingredient that has a shelf life of about 15 months (2). So, lets answer the most important question.
How Long Do Shampoos Last?
It is difficult to estimate the viability of products like shampoos, conditioners, and other cosmetics. Some work well even 2 years after opening while some go bad within 6 months. It depends on a few factors:
Composition:
Natural ingredients in shampoo may decrease its shelf life. This is where it becomes necessary to add preservatives. So, if you are buying preservative-free, all-natural, organic shampoos, you may have to use them up quickly.
Storage Conditions:
A 1986 study conducted in the USA found that shampoo preservatives lose their effect over time when stored at higher temperatures. When stored at 49°C, shampoos may go bad within 1-3 months (3). So, follow the manufacturers recommendations and store them in a cool and dry place.
Handling And Contamination: Like most cosmetics, shampoos also run the risk of microbial contamination. When you draw out the shampoo by hand or share a bottle of shampoo with someone who has used dirty hands things can go awry.
Using hands or fingers to extract shampoo out of a container may introduce bacteria or fungi in the formula. When coupled with improper storage conditions, these microbes can survive in the shampoo for up to 30 months (3). No amount of preservative can restore or preserve the product in such cases.
Authenticity: Look for authenticity seals and sealed shampoo containers. You could get tricked into buying fake/counterfeit expired products that are sold for a lower price. Expired shampoos can also be rebottled and repurposed as new ones. It is, therefore, important to buy from a well-known source/seller or directly from the manufacturer.
So, how can you figure out if your shampoo has expired? Find out in the next section.
How Can You Tell If Shampoo Is Expired?
In most cases, it is not easy to identify if the shampoo has gone bad just by looking at the bottle. Also, very few brands/manufacturers endorse the shelf life of their products as it is not mandatory to share these details (4). To make matters worse, there are no laws or regulations that require certain cosmetics to print specific shelf lives or expiration dates on their labels. Regulatory bodies like the USFDA hold manufacturers responsible for product safety (4). So, unless there is an evident physical change in the shampoo, you may not know if it has expired. Here are a few changes to look out for:
Check the crimp, back, bottom, or packaging material for manufacturing and expiry date. If no such information is printed, look for a symbol that looks like a small container with the lid off. It should have a number with the letter M printed. This indicates the number of months you can use the product after opening. For instance, 12M is 12 months, 15M is 15 months, 24M is 2 years, and so on. If a shampoo has not been in use for a while, swirl the bottle to shake it well. Check for any lumps or color changes. Some oil-based formulas can separate into layers. If they have become distinct and immiscible, it is time to discard the shampoo. Smell or odor is another key indicator. Don’t use it if you catch an unusual odor coming off the shampoo bottle. Natural, herbal, and/or Ayurvedic shampoos may have a shorter shelf life. They may also release oils and spoil the packaging. Handle and dispose of such products with care. Fungi, molds, and bacterial growth may occur on the surface of the formula if the shampoo is left open. Don’t open, sniff, or touch such bottles. Old shampoos either don’t lather well or leave a soap scum. They make your hair gummy and straw-like. If it just does not feel right to touch, don’t use it!
Is It Safe To Use Expired Shampoo?
The answer to this depends on whether you are using a preservative-free shampoo or not. In the absence of preservatives, some shampoos may undergo chemical changes. Improper storage can accelerate such changes (3). Such shampoos may feel different on your hair. They may start to leave soap scum or lather less than usual. They could also have bacterial or fungal growth invisible to the eye. Using contaminated shampoos may trigger undesired side effects on your hair, scalp, and skin. This could often happen with natural or organic shampoos and hair care products. However, there is no scientific evidence to prove any of these effects. Some unopened chemically stable shampoos may work perfectly even after 2 years of manufacture or purchase.
The Bottom Line
Is shampoo good after 5 years? No, a shampoo is not good for use after 5 years. In fact, it may not be as effective even after 18 months from the date of manufacture. Can old shampoo cause baldness? It is unlikely that expired or old shampoo causes hair loss or baldness. But it may cause itchiness due to changes in the chemicals used in its formulation. How long is shampoo good for after its expiration date? Depending on the ingredients and preservatives used in shampoos, they have a shelf life of six months to eighteen months. Post expiry, there is a possibility of fungal or mold growth. An unopened bottle of shampoo can last for 2-4 years.
