There’s no denying that a great skin care regimen (sunscreen included!) can keep your skin looking healthy and radiant over time, especially since prevention is key.
However, there’s always room for cracks in even the strictest of 10-step routines, as there may be some unforeseen factors at play that can hinder the effectiveness of your product.
To shed some light on why your products aren’t working the way they should, we tapped six board-certified dermatologists to break down everything from weather changes to medications that may be messing with your skin.
Read on to reveal 11 reasons why your skincare products may stop working according to dermatologists.
1. Your Product Has Expired
Just like your food, your skin care products may also expire, making them not as effective as they once were, according to board-certified dermatologist Blair Murphy-Rose.
This makes it important to check your product labels for an expiration date before you shop, she added, so you won’t waste your hard-earned money on a product that doesn’t work as long as it should.
“I find that patients’ retinoid creams often expire while there’s still plenty left ― so it appears that the product has stopped working, but really the product just needs to be replaced,” she said. “It usually occurs about four months after opening, as even if the expiration date is ahead in the future, once opened the product seems to be less long-lived.”
2. You’re Storing Your Products Incorrectly
Although it’s easy to gloss over storage instructions on any product label, Rose said it’s important not to ignore them, especially since direct sunlight (or hot and humid environments) can break down the active ingredients used in your products.
“Vitamin C serums often expire, and therefore will lose that powerful antioxidant effect,” she told HuffPost. “The best way to get the most out of these costly serums is to store them out of direct sunlight, and to even refrigerate them ― which gives the added benefit of a cold, soothing application.”
3. Your Body Becomes Used To Your Product
As odd as it may sound, board-certified dermatologist Jeffrey Fromowitz explained that it’s possible for a product to stop working after your skin becomes used to it, making it important to rotate your products every so often.
“The body simply adjusts, and using the product becomes the new normal for your skin,” he said. “Sometimes changing routines, products and order-of-use can lengthen the amount of time a product gives you positive skin benefits.”
4. You Aren’t Paying Attention To Important Weather Changes
This one shouldn’t really come as a surprise, but board-certified dermatologist Peterson Pierre told HuffPost that your skin care concerns can vary depending on the season.
“Environmental factors can definitely interfere with the efficacy of your skin care regimen, so it’s important to be aware of that and make the necessary changes to keep your skin looking its best,” he told HuffPost. “Winter can cause the skin to get red, dry and irritated, while the hot and humid summer months can lead to oily skin.”
5. You’re Experiencing Hormonal Changes
Hormonal changes can also impact your skin, even when you aren’t on your period. Pierre said that other hormonal changes (associated with pregnancy, menopause or any hormonal imbalances) you may be experiencing can also have an effect on your skin care regimen.
With this in mind, he advises switching up your skin care products often to help combat any acne, dryness or irritability that may arise.
“Your skin can get oily and develop acne or it can get dull, dry and irritated,” he said. “It’s important to switch up your regimen to adapt to these changes.”
6. Your Medication May Be Causing Problems For Your Skin
Whether internal or topical, Pierre said that medications can be another sneaky culprit behind your skin care woes. Certain medications, he explained, can cause irritation to your skin, making it important to talk to your doctor (or dermatologist) if this is of concern.
“Certain medications can stimulate oil production and acne, while others can cause rashes and red, dry, irritated skin,” he said. “This may require an adjustment to those medications, and certainly a change in the products you use.”
7. You Aren’t Applying Products At The Right Times
Board-certified cosmetic dermatologist Austin Cope suggested that timing may be one of the surprising reasons your skin care products aren’t working the way they should, as products like retinol, for example, are products that should be applied before bedtime and not during the day.
“Retinols are very important, but they need to be applied at nighttime before bed,” he said. “If you wear them during the day, they are deactivated by the sun.”
Similarly, he said this same concept applies to sunscreen, as he suggested that many people forget to reapply their block throughout the day.
“In order to get full protection, you need to put on more sunscreen than you think is necessary,” he said. “This is problematic, because people who wear sunscreen put it on in the morning.” Then, after it’s been deactivated 90 minutes later, those people “have a false sense of security that they are still protected throughout the day.”
8. You Aren’t Consistent With Your Routine
Along with the importance of switching up your product use based on the weather, expiration dates or hormonal changes, it’s key to maintain a daily routine and try to give your skin time to adjust to it.
“The number one reason products stop working over time is the same reason diets stop working over time ― we stop doing it consistently,” he told HuffPost. “Consistency is key, as once someone falls off the consistency bandwagon, they then begin to wonder why treatments aren’t working as well as they used to.”
9. You Aren’t Exfoliating Enough
A lack of exfoliation can be another reason your serums and essences may not be working, as board-certified dermatologist Marisa K. Garshick explained that a layer of dead skin cells can prevent your product ingredients from effectively penetrating your skin.
“If skin care products are no longer helping, it can be helpful to consider exfoliating if you are not doing so already,” Garshick said. “Exfoliating a few times per week helps to get rid of the layer of dead skin cells, which enables better penetration of product ingredients.”
10. Your Product Isn’t Strong Enough
This rings especially true for products such as antiperspirants and retinol, as Garshick said that if these products are continuously used at a low strength, they may not be as effective.
“People prefer to start certain skin care ingredients such as exfoliants, retinoids and antiperspirants at a lower strength to ensure they can tolerate it,” she said. “However, if someone is no longer seeing benefits, it often makes sense to increase the strength.”
11. The Condition Of Your Skin Changes
Although your skin type never changes, cosmetic dermatologist Michele Green said it’s more than possible that your skin can go through different cycles. This makes it important to rotate your products often, she added, as you’ll want to ensure you address any skin concerns at a particular time.
“Sometimes your skin can go through different cycles such dehydration, dullness, oiliness or dryness; factors that influence this can be due to climate change,” she said.
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Lip Balm: Vaseline Lip Therapy
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Face Wash: Neutrogena Pink Grapefruit Cream Cleanser
Face Wash: PanOxyl Acne Creamy Wash
This article originally appeared on HuffPost.