Retinol and vitamin C are two of the most powerful ingredients for your skin. Both are known to fight wrinkles, build collagen and fade dark spots and pigmentation.
But fitting them into your skincare routine can be tricky. Should you layer one on top of the other? Which one goes on first? Do you need to wait in between them? And what about mixing them together?!
In this tutorial, you will learn:
- Whether you can apply retinol and vitamin C at the same time
- Why you need to consider pH and solubility
- The best ways to use retinol and vitamin C in your skincare routine
- My top retinol and vitamin C product picks
I've also got a free cheat sheet for you to download at the end of this article!
Can You Apply Retinol and Vitamin C at the Same Time?
Adding both retinol and vitamin C to your skincare routine is unfortunately not as simple as layering one ingredient over the other, or just mixing them together.
In fact, doing either of those things could be a waste of your time and money.
If you're going to get the most out of these ingredients, you NEED to be aware of two factors: pH and solubility.
Here's what happens to them when you use retinol and vitamin C at the same time, and why it matters.
✘ The pH Levels May Change
All skincare products that are water-based (aqueous) have been formulated to work at a certain pH. Skincare products that don't contain water, known as anhydrous solutions, don't have a pH.
- Retinol typically has a pH between 5.0 and 6.0, as research has shown that's where it operates best. The same goes for other over-the-counter retinoids such as retinaldehyde and retinyl esters.
- L-ascorbic acid, the active form of vitamin C, needs to be at pH 3.5 or lower in order to effectively penetrate your skin (as this study proves).
Since retinol and L-ascorbic acid have a big gap in pH, using them at the same time will lower the retinol's pH and raise the vitamin C's pH.
✘ They May Not Dissolve or Penetrate
The next thing to think about is whether the ingredients are oil-soluble or water-soluble.
- Retinol is oil-soluble, so it will only dissolve in oil.
- L-ascorbic acid is water-soluble, so it will only dissolve in water.
Oil and water don't mix. So if you're adding a water-soluble vitamin C (for example, an L-ascorbic acid powder) into an oil-soluble retinol, it will not dissolve. That means it won't penetrate your skin, and you won't get any of the vitamin C's benefits.
Another thing to keep in mind is that oils can create a barrier on the skin that blocks the absorption of water-based products—another reason not to mix oil-based and water-based solutions.
The Best Ways to Apply Retinol and Vitamin C
Fortunately, there are a few ways to incorporate both vitamin C and retinol in your skincare routine without sacrificing any of the benefits.
You've got four options:
✔︎ Vitamin C in the Morning, Retinol at Night
Your easiest course of action is to separate vitamin C and retinol from each other and apply them at different times of day. This ensures that each ingredient can work at its correct pH.
✔︎ Vitamin C and Retinol on Alternate Nights
Most dermatologists believe that retinol should always be applied at night, away from UV light. But did you know that you can apply vitamin C at night, too? This study found that DNA damage continues for hours after exposure to UV light, and suggests it could be prevented with a nightly antioxidant, like vitamin C.
By using retinol and vitamin C on alternate nights, you'll get the benefits of both, without having to worry about interactions.
✔︎ Vitamin C and Retinol at Night, 30 Minutes Apart
If you must use retinol and L-ascorbic acid at the same time, separate them by 30 minutes. Apply your vitamin C first, since it has the lower pH of the two. Then, wait half an hour before you apply your retinol.
Incorporating the waiting period allows your skin's pH to return to normal, so each ingredient can work at its intended pH.
✔︎ Vitamin C Derivative and Retinol at Night
If you don't have time for the 30-minute waiting period, but you still want to use retinol and vitamin C at the same time, then your best bet is a vitamin C derivative.
Vitamin C derivatives have to be converted into the active form of vitamin C, L-ascorbic acid, in your skin. So they're not as potent as L-ascorbic acid itself. However, they tend to be more stable and less irritating, and offer many of the same benefits (including protection from free radicals, brightening and in some cases, even boosting collagen production).
As long as you choose a vitamin C derivative that is close in pH to your retinol, then you can use them at the same time, since they will not destabilize each other.
Choose formulas with one or more of these vitamin C derivatives:
- Ascorbyl glucoside (pH 5.0 to 7.0)
- Ascorbyl tetraisopalmitate (pH 4.0 to 6.0)
- Ethyl ascorbic acid (pH 4.0 to 5.5)
- Magnesium ascorbyl phosphate (pH 6.0 to 7.0)
- Sodium ascorbyl phosphate (pH 6.0 to 7.0)
Which ingredient goes on first? In general, you want to apply your products in order of lowest to highest pH. However, be mindful of textures. Lighter, water-based solutions must be used before more occlusive, oil-based ones—otherwise, they won't penetrate.