How Long Can You Keep Your Natural, Nontoxic Skin Care Products?
It's no secret that people have been paying close attention to their skin care labels recently, as the rise of natural skin care has inspired even the most traditional of retailers to launch organic-focused campaigns in the hopes of earning a seal of approval from the clean beauty community. But what most people don't realize is that we can't be treating our natural products exactly the same as their synthetic counterparts because our natural favorites don't have those same synthetic parabens that extend their shelf life for months (sometimes years) on end.
That doesn't mean clean beauty is completely preservative-free—natural brands (and especially the bigger, household names) have formulated natural preservatives that do extend the shelf life of their products for a time. No need to worry about getting an infection from using an avocado mask after the date a real-life avocado would traditionally expire.
But what's different about these natural preservatives is that they tend to be comprised of organic substances that allow for a longer—but not as long—shelf life. Cosmetic chemist Ron Robinson tells me that organic acids, such as levulinic, sorbic, and benzoic acids, are commonly used as preservatives in natural brands, while board-certified dermatologist Ellen Marmur, M.D., mentions that ingredients like honey and lemon can also help extend a product's shelf life.
So what is the shelf-life of our natural beauty go-to's, and why does it matter?
Your first and best rule of thumb is already on the bottle: The brand-approved shelf life is depicted by a number followed by the letter M. This is going to be your expiration date, the same as you would see on food items. But that's not the only thing to look out for, as expiration dates are only a fraction of the story: Products can become inactive or spoil due to air or light exposure, so you need to be mindful of these signs, too.
According to board-certified dermatologist and co-founder of Dr. Wang Herbal Skincare, Steven Wang, M.D., we have to think of shelf life in terms of three layers when it comes to beauty products. "From a conventional sense, a product's shelf life is when the product 'goes bad,' which can be defined as changing color, changing temperatures, phase separations, and a changing of odor," he says. "But you can even dive deeper and think of shelf life in terms of how well the preservatives are protecting a certain product. Then you can even go further and think about the functional shelf life of active ingredients."
And although labels might not disclose this information, the formulation of different products is especially important in terms of shelf life. "Different formulation and manufacturing processes can accelerate, prolong, or shorten, the shelf life," Wang states. For example, the conventional approach for testing a product's shelf life uses heat in order to bind ingredients together and preserve its shelf life, so the two phases won't separate. Ironically, in the process of doing so, this high temperature can damage the important (and fragile) actives in the product, like vitamin C and retinol.
"The problem is," Wang says, "once you heat something, you destroy the active ingredients, such as vitamins and antioxidants. Like when you cook vegetables for too long and it destroys the nutrients. Likewise, when you put a formulation through a very high temperature, you can accelerate the degradation process and cause a loss of functional activity for the active ingredients." Translation: By the time you pick it up in the store, it's lost much of potency already.
To make a complicated, nuanced introduction short, when it comes to skin care shelf life—first, pay attention to your labels. The period-after-opening date found on the bottle is your absolute "must-toss" marker: Do not ignore this label. Then, be sure to keep an eye out for these additional key indicators below to make sure your product is as potent as possible. Because when people aren't knowledgeable about when it's time to restock their natural products, the formulations can be harmful to our skin rather than helpful .
Although it might kill you to have to dispose of a highly coveted $75 night cream (I've done this, and it was almost physically painful), just remind yourself that you're ultimately doing the right thing for your skin. Call it a "skin care sweep," if you will.
Cleansers: approximately 6–12 months
For our favorite liquid or cream cleansers, you'll know when you're due for a refill when the product starts to separate, meaning the oil and water components that are usually bonded together are starting to break apart: Keep an eye out for these first clues of this separation process, and toss accordingly. Another thing to be mindful of: "Liquid and cream cleansers typically have a shelf life of six months, as their moist formula puts them at risk to develop bacteria," Marmur says.
Oil cleansers, on the other hand, are a little bit of a different story. "For oil cleansers in general—if it's made of pure oil—the shelf-life might perhaps be a little bit longer," Wang says. "In theory, there won't be any phase separation (the separation of oil and water) because the cleanser only contains oil. If the oil has only natural oils, when it becomes exposed to air and light, the oil can become rancid or spoiled." According to Wang, you can identify a rancid oil by its color, smell, and texture, and each oil has a different timeline.
Toners: approximately 6–12 months
If you make your own formula, like a rosewater toner, you'll need to toss it in about six months, says Tina Hedges, founder of LOLI Beauty, because these homemade concoctions don't contain any preservatives at all, unlike store-bought natural toners. The water content in these products makes them breeding grounds for bacteria, which is why they need these preservatives in order to even make it on the shelf. "It's so dependent on how they have been formulated," she explains. "If it's a store-bought toner that contains 80 to 95% water, then it most likely has a chemical preservative and should have a fairly long shelf life—like 12 to 18 months."
In terms of the difference between astringent versus moisturizing toners, Wang says it's important to check your toner labels for any traces of oil.
"An astringent toner may have more alcohol, or perhaps less oil concentration, where perhaps with a moisturizing toner, there probably is a little more oil content in it," he says. As mentioned above, products with natural oils can "go bad" when exposed to oxygen over time, so it's best to check out the oil content on your toner labels.
Serums: approximately 6–12 months
When it comes to serums, we know that it's best to use them when they're at their most active. Because serums penetrate deep into the skin, locking in moisture and nutrients, it's important to time these guys just right—and care for them preciously. You can ruin a perfectly good serum by keeping the cap open or in the sun.
The good thing is that there are usually visible markers of a serum gone bad, so you can easily identify which ones you need to toss, ASAP. "Consumers should make sure that their vitamin-C-based products have not shifted orange or brown because that is an indication that the product has begun to oxidize, thus no longer active," Robinson says.
"Vitamin C is the most notorious one," Wang agrees. "It has the shortest shelf life because of its water-soluble antioxidants. When it's exposed to water and air, it becomes degraded." While products can be formulated to have one good year of shelf life, it's important to notice these visible signs of degradation to be absolutely sure.
In terms of the other serums (hyaluronic acid, AHA, BHA, peptide, ceramides, the list goes on…)? Those should all be fairly stable. The only other serum of note is retinol, that vitamin-A-derived product we've come to know and love for its anti-aging, skin-firming properties. "Consumers should make sure that the product is packaged in an opaque and airtight package," Robinson advises. This way, the serum is safe from exposure to air and light, which can cause its degradation.
Oils: approximately 3 months–2 years
"Here's the thing about different oils," Wang explains. "Coconut, jojoba, rosehip, grapeseed—all these oils have different concentrations of unsaturated fatty acids, and when they're exposed to oxygen and light, this exposure will break down the double bond that causes the activation and rancidity, which will change the color, smell, and feel of products."
While there's a wide range of concentrations of fatty acids in different types of natural oils, Marmur offers her medical advice on two oils in particular: "Rosehip oil mixed with vitamin E can last up to two years, but if it is by itself, it will only be good for six months," she says. "Grapeseed oil is only good for three months unless it is stored in the refrigerator. Then it will be good for up to six months."
Masks: varies by type
Masks tend to be tricky to categorize into one shelf-life umbrella because there are so many formulations on the market. From clay masks to enzyme, to charcoal masks, to sheet, each type contains a different set of ingredients that react differently when exposed to air and water.
Masks that are already activated (think your standard cream or jelly masks that are ready to be lathered on) usually contain water. Water, as we know all too well by now, breeds bacteria and therefore needs certain preservatives added to the mixture so retailers can sell their products without needing a quick turnaround.
But masks that are sold unactivated tend to have a longer life span. For example, Wang mentions, "If a mask is comprised of clay and powder, that should have a really, really long shelf life because there's no exposure to water or oxygen. There are masks where sometimes you do have exposure to water, which creates that chemical reaction. And that will actually shorten its shelf life."
So, a creamy avocado mask would tend to "expire" way before a powder mask you activate with water yourself. Plus, some powder masks allow you to activate with whatever substance you'd like, so you can get creative with the base (yogurt, Manuka honey, and jojoba oil are just a few options to try).
The bottom line? There's a lot to consider.
According to Wang, we should be well versed on the preservatives in our go-to products. "People who go out and buy natural products that are not adequately preserved run the risk of fungus, yeast, and bacteria growing in the product once they open it," he says. "If they keep using it for three to four months, that contamination process can theoretically cause breakouts, rashes, even infections."
After you consider yourself well-versed in skin care labels, Marmur advises opting for products that are least likely to encounter chemical reactions. "Anything soothing and moisturizing is your best bet for longevity in natural skin care," she advises.
Finally, keep in mind that water is a breeding ground for bacteria, and products that are made of mostly H2O tend to either have extra-short shelf lives or are jam-packed with preservatives. If you're truly looking to go preservative-free, "Look for waterless, pure, and minimally processed oil or powder blends or salves and balms," Hedges says.
Regardless of which products you decide to display in your bathroom cabinets, remember that beauty products always have a shelf life no matter what (and any lifetime guarantee should be alarming rather than reassuring).
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