Hey, I'm Tenneil

I live in Perth, Australia, and this is my creative outlet where I blog about beauty, my life and everything in between. I enjoy the '80s, the '90s and anything French, and some of my favourite things in life include music,  film, summer and a nice cup of tea.

How to Layer Your Skincare

How to Layer Your Skincare


Our everyday skincare routines have come a long way since the good old cleanse, tone and moisturise, and with huge advancements in skincare science constantly being made, the more elaborate they become. Being on the right side of thirty now, I've begun introducing more complex and active products into my routine to help prolong the signs of ageing, and as I wasn't exactly sure how to incorporate retinol in with the rest of my products, I began some research into how I should go about layering skincare. While I understand how all too easy it is to get caught up in whatever's popular, sometimes we need to delve a little further and educate ourselves how the products we use work and not just rely on blogger hype. Little did I know that I would be lead down a skincare rabbit hole full of scientific jargon my right-brained head could barely get around, but I learnt a lot and thought I'd share my newfound knowledge with you all.

My skincare routine

Being the beauty enthusiast that I am, there are quite a lot of steps in my skincare routine and also because I find it more beneficial to use products that have singular and targeted purposes. Using skincare with specific functions means I can customise and curate my routine according to what my skin needs day-to-day, and as everyone's skin type is unique and we all have different concerns, you'll be hard pressed to find a sole product that caters to all your individual needs. Do-it-all type products may not even do all that they claim to as well. For example, a cleanser that claims to fight anti-ageing and contains retinol is simply a marketing scam because retinol needs to stay on the skin in order for it to work and obviously, with cleanser, you wash it off. 2-in-1 type products aren't necessarily bad, but I say this to simply highlight why I enjoy a multi-step routine and why you should always do your homework before buying. I've listed the order of how I apply my products below. 


  1. Oil-soluble cleanser
  2. Water-soluble cleanser
  3. Exfoliating toner
  4. Retinol
  5. Hydrating toner
  6. Serum
  7. Spot treatment
  8. Eye cream
  9. Moisturiser
  10. Oil


  1. Water-soluble cleanser
  2. Vitamin C serum
  3. Hydrating toner
  4. Hyaluronic acid serum
  5. Moisturiser
  6. SPF (chemical)




I certainly don't use everything all at once (to do so requires too much dedication and would probably do more harm than good) and I chop and change things depending on how my skin is looking, what I can be bothered with and what products pair well together. I do face masks every 1-2 weeks and for the most apart, applying my skincare is ritualistic and something I quite enjoy too. There are a few key things I also want to point out:

  • Vitamin C works best on clean skin and should come first before toner.
  • Toner is a catch-all term for anything that's basically a lotion and there are a lot of different types. I have one exfoliating toner in my routine and the rest I own are hydrating as I have dehydrated skin.
  • Moisturiser is commonly the final step in a nighttime routine, but it's my understanding that using oil last will seal and lock in moisture and that moisturiser can't penetrate through the oil barrier. If you use facial oils, alternatively, you can blend them together too.

pH levels

Understanding how pH levels work and the role they play in both our skin and our products is integral in developing an effective skincare routine. Simply put, pH is the chemical measurement used to express the acidity verse alkalinity of a solution based on a scale of 0 to 14. Anything less than 7 is acidic and the closer it is to 0, the more acidic it is. On the other hand, anything over 7 is basic and the closer it is to 14, the more basic it is. A pH of 7 is considered neutral and our skin's pH level can fluctuate anywhere between 4 to 7; this can be due to a variety of reasons, such as skincare products and even the water we use to wash our face. Healthy skin is acidic (ranging from 4.2-5.6) and the lower your pH, the better condition your skin will be in as acidity resists bacteria (bacteria, including acne, grows better at a neutral pH) and prevents your skin from losing water, just to name a couple of its benefits.

Maintaining a low pH level is by and large to do with our cleanser and simply washing your face with water can even raise its pH. To combat this, a good cleanser should be acidic and no more than a pH of 5.6. Anything higher will not only raise your skin's pH, but also keep it that way, leading to damage to your skin barrier, as well as breakouts. Admittedly, I'm not sure of the pH levels of my cleansers, but I can only assume that they are relatively low as my skin is normal, albeit on the dehydrated side. This is definitely something I'll be looking into and confirming though.


Actives and wait times

"Actives" is the term given to pH dependent skincare products that have direct, active results on the skin and are the only products that cause true purging. As exfoliation results in the skin pushing the blockages inside of it out to the surface, you can't purge from products like moisturiser or sunscreen and if you think you are, it's more than likely a breakout and the product probably isn't for you. Vitamin C (the L-Ascorbic Acid kind), Vitamin A (retinoids such as retinol and tretinoin), Alpha Hydroxy Acid (AHA), Beta Hydroxy Acid (BHA), and Polyhydroxy Acid (PHA) are all examples of actives and will require a 15-20 minute wait time in between applying them in order for your skin to adjust its pH level after cleanser. Acids - that's L-ascorbic acid vitamin C, AHA and BHA - are most effective at a low pH level and applying your skincare routine one after another without the wait times means your skin won't fully absorb and activate the product. If you're impatient, your acids will still absorb to an extent, but you'll potentially be compromising its efficacy and you're not really going to get the most out of your skincare that you probably spent a lot of money on. Contrary to acids, vitamin A's efficacy is dependent upon a more basic pH, but a wait time of 20 minutes before applying is advisable so as not to disturb your skin's natural barrier and possibly cause irritation. Waiting another 20 minutes to an hour before applying moisturiser is recommended too as you may diminish or disrupt its potency.

While you can use actives during the day, I prefer using them at night when my skin isn't going to be exposed to the sun and when I can unwind for the day, taking more time and care with my routine. On a side note, AHA and vitamin A make your skin photosensitive (the increase in the reactivity of the skin to sunlight) and vitamin A can even break down from sun exposure. I only use one active a night, so I'm not doing too much waiting around and because I really don't think my skin needs that much exfoliation. You can use more than one active in a singular skincare routine (layering them in order of lowest to highest pH) if you wish, but for myself, I don't want to overdo it and potentially cause irritation. At the moment, I alternate each night between using Biologique Recherche Lotion P50 and The Ordinary Advanced Retinoid 2% (the two actives I currently own); cleansing then waiting, applying my active, then waiting again before I go in with the rest of my routine. Although I've seen pretty great results without the waiting times using Lotion P50 (at this time, I had only researched how to use retinol and hadn't extended it to other actives), if you want more effective results quicker, the wait times will be worth it.

Having said all this, wait times aren't for everyone. Not all of us have that kind of time and patience, it can make your skin feel dry and uncomfortable, and my research also indicates it to be extremely subjective. Some notice a difference waiting, others don't. Alternatively, you can simply wait until the skin is dry (application to damp skin will cause faster absorption and potential irritation), use a pH adjusting toner to remove the wait time (they may lead your actives to over-exfoliate your skin though) or even choose not to use an active every day. The only thing you can do is experiment, listen to your skin and find out what works best for you.


Skincare ingredients that pair well together

  • Retinol + Hyaluronic Acid: retinol does a whole host of good stuff for the skin; it unclogs pores, exfoliates, boosts collagen to reduce fine lines, speeds cell turnover, evens out discolouration and smooths the skin. Being the potent ingredient it is, your skin may purge or become irritated during the initial stage of use, so to combat this, pairing it with hyaluronic acid works a treat to balance out and replenish the skin. The thinner of the two should be applied first (more on that below) and remember that hyaluronic acid works best when the skin is damp.
  • Vitamin C + SPF: vitamin C is a powerful antioxidant that not only boosts radiance and helps fade sun damage, but also aids SPF in protecting your skin, making it less sensitive to light. While you can use vitamin C at night, I find it more beneficial for daytime use as you don't necessarily need radiant skin or photoprotection while you sleep. Keep in mind that L-Ascorbic Acid Vitamin C is efficient at a low pH level, but if you don't want to wait around in the mornings, you can opt for a non-pH dependent vitamin C. I use Glossier Super Glow, which is an aminopropyl ascorbyl phosphate.
  • Vitamin C + Vitamin E: these two vitamins are both antioxidants and together, their components complement each other to help replenish and repair skin cells. Vitamin C restores vitamin E's antioxidant function so that it can continue to fight tissue damage, and as they both neutralise free radicals caused by sun exposure, the combination of the two provides greater efficacy in photoprotection. Vitamins C and E both work together to maintain healthy collagen and protect the skin against environmental pollutants, so if I'm going to be outside a lot on a particular day, I love layering Glossier Super Glow underneath my Mecca Cosmetica To Save Face Superscreen SPF 50+, which contains vitamin E.

Skincare ingredient pairings to be cautious of

  • Retinol + Acids: combining acids with retinol will make them more potent and therefore, more likely to irritate the skin. Since retinol also works best at a more neutral pH and acids are optimised at a lower pH, applying retinol beforehand will render your acids ineffective too. If you'd like to boost the penetration of your retinol, however, you can apply AHA first, wait an hour and then go in with retinol. Alternatively, you can apply AHA during the day; it all comes down to how sensitive your skin is and how much waiting you're willing to do.
  • L-Ascorbic Acid Vitamin C + Niacinamide: L-ascorbic acid vitamin C needs a low pH level in order to be effective and when combined with niacinamide, the acidity converts it to niacin, which can cause flushing and redness in sensitive skin. Combining the two isn't harmful - waiting 20 or so minutes will stop the two from reacting together - but the general consensus seems to be to proceed with caution and most people tend to opt for vitamin C during the day and niacinamide at night.
  • AHA + BHA: combining AHA and BHA can cause over exfoliation, but if you're skin is resilient, you can slowly work your way up to using both (introducing one at a time) and find out what your skin can tolerate. BHA works to "degunk" the skin and is oil-soluble, while AHA "unglues" it and is water-soluble, therefore BHA should come first so that the AHA can penetrate better. If your AHA has a lower pH, however, then that will come first and most people tend not to have waiting times in between applying them as they function at similar pH levels. Be careful of using L-ascorbic acid vitamin C with your AHA and BHA too as all that acidity can cause irritation.
  • Retinol + Benzoyl Peroxide: retinol and benzoyl peroxide both work well to treat acne, but the combination of the two can deactivate each other and cause flakiness, redness, peeling and irritation. If you absolutely must use the two together, spot treat with benzoyl peroxide and apply your retinol everywhere else.
  • Vitamin C + Copper Peptides: copper is a mineral that's attached to peptides to promote absorption and together, they encourage elastin and collagen formation to enhance wound healing. Interaction between copper peptides and vitamin C causes the breakdown of ascorbic acid in solutions, therefore cancelling each other out and rendering them both ineffective. To use both in a skincare routine, you can apply them on alternate days, use one or the other day or night, or apply vitamin C first, wait 20 minutes, then apply your copper peptides. 

Day or night?

I'm not a morning person and like to sleep in as much as I possibly can, so I keep my daytime skincare routine relatively basic and as I mentioned, reserve my actives for nighttime use. Actives are okay to use during the day and this Paula's Choice article says even retinol is safe, but I'm apprehensive and personally wouldn't risk it in the harsh Australian sun. While both retinol and AHAs are photosensitive (BHAs aren't), the photosensitivity effects of AHA are long term and can last anywhere between a few days to a week, so whether you use AHA day or night, remember to always wear sunscreen. Regardless if you're using actives or not, wear sunscreen!

I feel like you get the most out of vitamin C applying it during the day and as my skin is on the dehydrated side, I wear hyaluronic acid both day and night (Glossier Super Bounce during the day and Estée Lauder Advanced Night Repair at night). With niacinamide (Glossier Super Pure and La Roche-Posay Effaclar Duo [+]), I'll usually apply it at night when I'm not using an active just because I can't be bothered layering a whole ton of product and also because dehydration is my main skin concern. On the occasion I've been looking a little spotty, I have also applied it during the day when I'm not using vitamin C. As I mentioned above, experiment to see what your skin likes (keeping in mind the ingredient pairings to be cautious of) and mix things up according to the skin concerns you want to address.

Thinnest consistency to thickest consistency

Building a multi-step skincare routine and knowing how to get the full potential out of your products can get confusing and overwhelming. Before I put this post together, I certainly wasn't aware of just how much science it involved. If you're unsure of your skincare's pH levels, the general rule of thumb is to go from thinnest to thickest and watery to oily. Essentially, you want to layer the "fat" over the "lean" because to apply them the other way around means the thinner products aren't going to penetrate the thicker ones. It's common sense, really. It's important to research before you buy so you not only know what's going on your skin, but how exactly to incorporate them into your routine. In any case, just remember these three key things: lowest pH to highest pH, thinnest to thickest and watery to oily.


Developing a solid skincare routine and learning what products work well for you is a process of trial and error, and as we all have different skin, different budgets and even differing lifestyles, these all factor in to how subjective skincare can be. At the end of the day, it's not a one-size-fits-all thing, so regardless of all the science, do whatever your skin likes best. I tried to make this post as comprehensive as I possibly could, but I obviously can't cover everything in a singular post and as there's only so much I can use on my one face, I chose to include information I found most relevant to me and the products I own. The science behind skincare can get quite extensive, but this learning process has actually been really fun and interesting, plus it ensures I'm getting the most out my products, my money and most importantly, that I'm looking after my skin properly. As I've already mentioned, do your own research if you have any concerns and if you'd like to read up more on layering skincare, I've linked below the resources I found the most informative and that helped me put this post together.

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