At some point, we all skincare devotees get there—that one holy-grail serum that we swore by the whole time suddenly doesn’t seem to be doing the trick anymore. We start to wonder if we’ve built up some kind of immunity to it, but the reality is much simpler. Our skin has just adapted to it. While there’s some truth to the fact that the skin can become less responsive to certain products over time, it’s not like it’s building up resistance to the active ingredients in the formula. So no, your skin doesn’t become immune to products—except for a very few—no matter how often or how long you apply them. Read on to see what’s really going on with your skincare routine that may be leaving you with the feeling that it’s not working anymore.
Why the idea that skin becomes “immune” to skincare isn’t a thing
First off, the idea that skin can develop immunity or stop responding to topical products is not supported by evidence. This is simply a theory that holds some truth and is related to tachyphylaxis. This hard-to-pronounce term has been going on in skincare for a while, and it’s used to describe the sudden decrease in the skin’s response to topical treatments.
However, this phenomenon mostly happens with topical steroids and antibiotics like erythromycin or clindamycin. These medications can cause the body to alter its molecular signaling pathways and result in a decrease in their effectiveness. But the thing is, tachyphylaxis doesn’t apply to everyday products like your favorite retinol and vitamin C.
What happens has more to do with the skin’s ability to acclimate to certain active ingredients which results in a plateau effect where the product’s results are maintained rather than increased.
The skin’s strongest response to products occurs upon the first application. Picture your skin like a curious adventurer exploring a new land, eager to discover all it has to offer. Upon first use of a product, your skin reacts with the enthusiasm of a kid, soaking up all the nutrients it can get its hands on. But just like with any other thing in life, it eventually acclimates to its surroundings and becomes familiar with what it’s dealing with.
As your skin becomes accustomed to the product, the initial boost in results gradually slows down as your skin reaches its peak and there’s not much left to improve. At this stage, the product’s effects shift from increasing results to simply maintaining them.
Your skin getting used to a product is actually a good thing
Think of retinol or hydroxy acids. Both stimulate cell turnover and cause peeling and redness for the first weeks. But as you continue to apply them, your skin gets better and better at shedding dead cells and growing fresher ones. During that time, you’ll see more changes in the texture and tone of your skin, and the flaking and irritation slowly go away. As the skin adjusts to the increased cell turnover rate, it may feel like the product is no longer making progress, but that’s a good sign. This doesn’t mean retinol became inefficient or you built an immunity to it, but your skin has improved and is now working more efficiently, which is exactly the purpose of a skincare routine—the skin gets less reactive and strong.
Now no one says you need to settle for results. You can always upgrade to more potent formulas once your skin has acclimated to a product. That’s actually the way to do it. Slow and steady. However, it’s best to wait at least six weeks before swapping between products. That’s the average time of a complete cell cycle and allows your skin enough time to adjust and for the new product to show results.
Skin doesn’t get used to non-actives
Our skin is adaptable to some degree and can become accustomed to certain active ingredients. However, this is not the case with non-active products like cleansers, moisturizers, and sunscreens. These products will continue to function effectively regardless of how long you use them. On the other hand, serums containing potent actives such as retinol or vitamin C may require alternating or upgrading to maintain their effectiveness over time.
What about acne treatments?
If you’re using topical antibiotics like clindamycin, then yes, the treatment may stop working since the bacteria on your skin can become resistant. There are exceptions, though. This study shows benzoyl peroxide works rapidly on P. acnes without causing antibiotic resistance.
Can a product stop working?
A skincare routine simply doesn’t stop working out of nowhere—rather, your skin changes due to environmental factors or things like stress or hormones. Or your skin may have been improved beyond what your current routine can do. The fact is that people are terrible at judging the state of their skin or the efficacy of products. If you no longer see results from your skincare routine, you have two options: either settle for maintaining the status quo or spice things up with more potent products.
Reasons why your skincare routine might not be working as well as it used to
There are a few reasons why your skincare routine may stop working:
- Tolerance: With repeated use of a product, the skin becomes more tolerant to its active ingredients, meaning the product will no longer have the same level of impact as it did initially. To maintain a constant increase in results, you need to use a different formula with a higher concentration of actives.
- Lifestyle changes: Environmental exposure, stress, and age can also affect the way your skincare routine is working. The same goes for seasonal changes—skin requires different care during the summer and winter months.
- Storage conditions: Exposure to light, heat, and air can degrade the formula and render the active ingredients ineffective long before the product runs out. Learn here how to store your skincare products to keep them fresh until their last drop.
- Lack of exfoliation: If dead cells are not removed through exfoliation, they can form a barrier on the skin’s surface and block the products from penetrating effectively. To increase your product’s effectiveness, exfoliate twice weekly.
- Consistency: Most actives give the best results when used for at least six weeks.
- Damaged skin barrier: If your skin is peeling every time, even a little, that’s a sign your moisture barrier is compromised. It could be because your routine isn’t moisturizing enough, you’re using harsh cleansers, exfoliating too much, or you have sensitive skin. Here’s more about how to fix a damaged skin barrier.
Read next: Can Your Skin Become Addicted To Moisturizers?