It’s a seemingly common skincare scenario: you fall in love with a new product, but after a while, it stops working.

Maybe it’s lost its mojo…or your skin has somehow become “immune.” But is that what’s really going on? To find out if your skin really does get used to products, we asked our resident skincare sleuth: dermatologist Dr. Sandra Lee (aka Dr. Pimple Popper).

Can you become immune to skincare ingredients?

Your skin does not build immunity to a product or ingredient. However, it is true that your skin needs time to adjust to certain active ingredients, particularly retinoids. This is why some people experience irritation — aka purging — when they first start using retinol or, more often, prescription retinoids.

Your skin growing accustomed to retinol use does not mean that the retinol is becoming less effective — quite the opposite, actually. After the initial period of irritation subsides, you should begin seeing positive results that will peak and level off somewhere between six and twelve months.

Looking for an effective retinol? Try SLMD Retinol Resurfacing Serum.

Do skincare products lose effectiveness over time?

For the most part, says Dr. Lee, your skincare products do not “magically” lose potency over time. If you’re using high-quality skincare formulas, they should remain stable for a predictable amount of time.

That being said, skincare product effectiveness can be variable, including when:

• They’re past their expiration dates
• You’re combining products with incompatible ingredients
• They’re exposed to extreme temperatures
• You’re making them yourself (like DIY masks)

Why aren’t my skincare products working as well as they used to?

It’s not uncommon to notice that while a particular product or routine seemed to work really well at first, you’re no longer seeing those same results. According to Dr. Lee, this is most likely due to reasons other than your skincare.

#1 You’ve gotten used to your results

In other words, says Dr. Lee, this is a perception problem: you’ve grown accustomed to seeing your skin looking healthier, and forgotten what it looked like when you started.

A clever way to solve this dilemma is to take your own “before” and “after” photos. Make sure you take your selfies from a similar angle, in identical lighting conditions. This will help give you an accurate idea of how well your skin health is progressing.

Send us your selfies! Click here to share your before and after photos from using Acne System (or any of your other SLMD faves) for a chance to be featured in our social media

#2 Your skin has changed

Although your basic skin type remains fairly constant, it’s quite common for skin to fluctuate throughout our lives. Here are just a few of the reasons why your skin could vary over time:

• Age
• Hormones
• Weather
• Stress
• Diet
• Sleep
• UV exposure

#3 You've started slacking

Think back to when you first started your new skincare routine. How excited you were to wash away all the dirt and oil of the day, pat on your treatment serum, slather on your moisturizer…and wake up to healthier skin.

Time for some tough love: are you still sticking to that consistent skincare regimen, now that the novelty has worn off? If the honest answer is no, then recommitting to your routine is a smart place to start.

Do I need to change up my skincare routine to maintain results?

The definitive answer? No — but yes. While your skincare products are probably still doing their job, those typical life changes that we discussed above are still happening all the time. Making adjustments, particularly as the seasons change, or even throughout your monthly cycle, can help optimize your routine.

Small tweaks — adding a hydrating serum (like SLMD Hyaluronic Acid Serum) during the winter, or upping your exfoliating frequency during the summer, for example — can make a big difference long term.