Skincare Ingredients Dos And Don’ts

By Susie 

  • Overwhelmed by all the different skincare products and ingredients out there?
  • Different experts often give contradicting advice on which ingredients can be used together and which ones can't, which makes it even more confusing 
  • We break it down, taking a very practical and realistic approach! 

It took me a long time to get into a consistent skincare routine. I think part of the issue was that I was overwhelmed by the amount of product in the market. There were things that peel, exfoliate, moisturize and hydrate…and while they sounded similar at times, the ingredient lists were all different. Was I supposed to use one, a few or all together?! 

What was even more perplexing is that different experts were giving contradicting advice on which ingredients could be used together and which ones should never be used at the same time.  

One school of thought seemed to really focus on the different pH levels of each ingredient and cautioned against using ingredients with different pH levels at the same time.  The logic being, they would counter each other’s effectiveness by disrupting each ingredient’s delicate pH balance.

On the other hand, many reputable sources were telling me this was all a myth and I didn’t have anything to worry about – the proponents of this approach were basically claiming any and all skincare ingredients could easily be combined and still remain potent. 

I finally asked Dr. Yoon about this and surprisingly, his answer was that both schools of thought were somewhat correct.  He clarified by saying, one was approaching the issue from a very theoretical perspective while the other was taking a more practical approach, noting lack of broad scientific studies to prove the underlying theories.  

With this knowledge in mind, I started exploring what might actually work for me and different skin types.  Since exfoliation is such a vital part of a solid skincare routine, I decided to start there. 

First up are acids, namely AHAs and BHAs. These are chemical exfoliants and they loosen and get rid of the gunk sitting on your skin. My question was - can these two be used together? AHAs will help give you smoother skin, BHAs will get into your pores to clean them. Sounds like a winning combo but apparently not for all. Layering these can lead to dryness and irritation in the skin. Combining these two is best for people with oily skin which tends to be less prone to sensitivities. 

Hopefully the above helps you identify which exfoliating acid you want to use.  The next question for me was, can it be combined with vitamin C? Vitamin C can exfoliate the skin as well, so layering acids with vitamin C can be effective in fading acne scars or sun spots. On the other hand, it can be irritating if used daily by people with more dry or sensitive skin.    

My favorite skincare ingredient by far has been retinol. While not technically an exfoliant, retinol is an antioxidant which can help restore the skin. I didn’t want to be too harsh on my skin so I wondered if I could use an AHA toner, vitamin C serum and retinol moisturizer together.  Would this be good for my skin or would it end up melting my face off? In particular, I was wondering how the different pH levels would come into play, since acids are better at pH levels between 3-4 and retinol is best at slightly higher pH levels of 5-7.

For this question, I asked my local dermatologist who knows my skin well. Turns out using a lightweight AHA or BHA can help retinol be more effective by dissolving skin cells that limit absorption. For me, she recommended that I use my AHA toner with both my vitamin C serum in the morning and also my retinol cream at night. 

She agreed that the different pH level concerns were theoretically true, but nothing to overly worry about, especially if these combos were working for my particular skin type. When I asked her about layering all of these together, she recommended I try it out to see how my skin reacted.  

So at first, I started using a vitamin C serum that also had AHAs in it in the morning and my retinol cream at night. I had some slight dryness that went away quickly. Eventually, I progressed to using an AHA toner, vitamin C serum, followed by a hydrating lotion and then a retinoid at night. Again, slight dryness at first that went away after a week or so. 

What I’ve learned through research, asking experts and trial and error is that everyone’s skin is different and combining these products can be safe and even beneficial for some, especially those with oily skin. 

Listen to your skin, if you do notice any redness, sensitivity, or excessive dryness, back off.  Try alternating, use skipping days or separate the products between morning and night. It’s also a great idea to start out with gentle and light formulations first to see how your skin reacts.