Ever since I shared my tutorial on the benefits of niacinamide, I've been asked how to use it with my OTHER favourite skincare ingredient: acid!

Take a look at this question:

If you've been wondering about this, too, this tutorial is for you! I'll cover:

• The benefits of using niacinamide and lactic acid, glycolic acid or salicylic acid 
• The problem with getting them from a single product
• The problem with mixing them together
• The three best ways to use them in your routine for maximum results!

Why Use Niacinamide and Acids

First, let's review the reasons WHY you'd want to include these two ingredients in your skincare routine.

Niacinamide (Vitamin B3):

• Works by giving our cells the energy to carry out their functions. 
• Treats a wide range of concerns, including pigmentation, wrinkles, acne, oily skin, large pores, redness, dryness, sallowness and a weakened skin barrier. 
• Has virtually no side effects and is generally well-tolerated. 
• Paula's Choice, The Ordinary, Good Molecules, Kristina Holey + Marie Veronique, Iron Power, SkinCeuticals and Glossier all offer niacinamide-based treatments.

Alpha- and beta-hydroxy acids (AHAs and BHAs):

• Chemical exfoliants that include glycolic acid and lactic acid (AHAs) and salicylic acid and its derivatives (BHAs).
• Both AHAs and BHAs exfoliate the skin surface, encouraging old dead skin cells to shed off, revealing fresh new skin underneath. 
• Can improve dullness, rough texture, hydration, hyperpigmentation and signs of aging. 
• BHAs have the added ability to penetrate into pores, where they loosen clogs and break down sebum. So they're also great for acne-prone skin, large pores and excess oil production. 
• Examples of AHAs include COSRX AHA 7 Whitehead Power Liquid, Kate Somerville Liquid ExfoliKate and The Inkey List Glycolic Acid.
• Examples of BHAs include COSRX BHA Blackhead Power Liquid and Paula's Choice Anti-Redness Exfoliating Solution with 2% Salicylic Acid.
• There are also AHA-BHA combination treatments, such as Omorovicza Acid Fix, Tarte Knockout Tingling Treatment and Glossier Solution.

The Problem with Getting Niacinamide and Acid from a Single Product

So, if you want niacinamide AND acid in your skincare routine, why not use a single product that includes both?

Well, it's a matter of concentration. 

To REALLY get the benefits of niacinamide, you're going to need a product with at least four or five percent, because that's the amount used in most of the clinical studies. 

For example, four percent niacinamide was proven to reduce pigmentation, fine lines and wrinkles and acne. Five percent was found to improve redness and sallowness.

Is the two percent that COSRX uses enough to do anything? (Apparently, ALL of their products with niacinamide contain a two percent concentration.)

Maybe. There are a few studies that saw two percent helped with pigmentation, oily skin and increasing hydration. If those are the only things you're looking to treat, then you might be fine with this low amount. But no, you won't be getting all of the potential benefits. 

Still want to go with a single product? Here are the best AHA and BHA treatments that also have niacinamide in their ingredients lists. (Note that COSRX is the only brand that is transparent about the exact concentration.) 

• COSRX BHA Blackhead Power Liquid: A niacinamide and BHA treatment with four percent betaine salicylate liquid (equivalent to about two percent salicylic acid) and two percent niacinamide. See my review here.
• COSRX AHA 7 Whitehead Power Liquid: An AHA and niacinamide treatment with seven percent glycolic acid and two percent niacinamide.
• Tarte Knockout Tingling Treatment: A 10 percent AHA-BHA complex with lactic, citric, malic, salicylic and acetic acids plus gluconolactone. They declined to tell me the percentage of niacinamide, but it is second on the ingredients list!
• Moon Juice Beauty Shroom Exfoliating Acid Potion: A glycolic, lactic and salicylic acid treatment. Niacinamide is the fifth ingredient.
• TULA Clear It Up Acne Clearing + Tone Correcting Gel: A two percent salicylic acid gel, with niacinamide halfway down the ingredients list.
• Derma E Acne Blemish Control Treatment Serum: A gentle 0.5 percent salicylic acid serum, with niacinamide around the middle of the ingredients list.

The Problem with Mixing Niacinamide and Acid Together

Alright, so you've decided that you want to use two separate products in order to get a higher concentration of niacinamide. 

Your best bets for high-dose niacinamide are:

• Paula's Choice 10% Niacinamide Booster: A 10 percent serum with a fast-absorbing liquid texture.
• The Ordinary Niacinamide 10% + Zinc 1%: A 10 percent gel-like serum with one percent zinc for added oil control.
• Good Molecules Niacinamide Serum: A new 10 percent serum, said to be an alternative to The Ordinary.
• Kristina Holey + Marie Veronique Soothing B3 Serum: A 10 percent gel made with clean ingredients. 
• Iron Power NiaSerum Niacinamide Serum: A 10 percent liquid available on Amazon.  
• SkinCeuticals Discoloration Defense: A five percent serum with added transexamic acid, kojic acid and HEPES to target dark spots.
• Glossier Super Pure: A newly reformulated five percent serum from Instagram's favourite beauty brand.

Now, what happens if you mix niacinamide with your AHA or BHA of choice, or layer one straight on top of the other?

One thing it's going to do is make your acid less effective. 

Acids typically have a pH between 3.0 and 4.0, while niacinamide is around 5.0 to 7.0. When you mix them together, the niacinamide will raise the pH of the acid. 

This study compared the absorption of AHAs at pH 3.0 and 7.0, and found that the higher the pH, the less the skin absorbs. That means you'd be missing out on all the benefits your acid has to offer.

Another problem with mixing niacinamide and acid is that it can cause redness and flushing. That's from the acid lowering the pH of the niacinamide, which triggers a conversion into niacin (another form of vitamin B3). 

If you've ever taken a high-dose niacin supplement, then you may have experienced the infamous "niacin flush." This is what it looks like:

Imagine the same thing, concentrated on your face! I've tested this out myself, and it's no joke. Makeup can't even cover it up! 

While it is temporary and harmless, who wants to have to wait a couple hours for their crazy red skin to go away? Nobody!

The Solution: How to Apply Niacinamide and Acid in Your Skincare Routine

To avoid the flushing issue and to get the most out of your products, you've got three options.

Option 1: Apply Them at Different Times of Day

An easy way to use both niacinamide and acid is to apply them at different times of day.

If your mornings are typically rushed, it's often most convenient to use niacinamide in the morning and acid at night. This is because niacinamide is non-acidic, so it can be applied underneath your hydrating serum, moisturizer, oil or sunscreen without having to wait in between layers. 

Acids, on the other hand, need to be separated from higher-pH products by about 30 minutes, to allow them time to work at their optimal pH. So, you may prefer to apply acid at night, when you have more time to wait in between steps (if you are using any other products on top of it).

That said, you can definitely reverse this and do acid in the morning and niacinamide at night, if you've got more time. Just make sure that you are wearing a good high-protection sunscreen (30 minutes after the acid) and avoiding prolonged direct sun exposure. AHAs in particular have been shown to make the skin more photosensitive and vulnerable to sun damage (whereas BHAs actually have some photoprotective effects).

Option 2: Apply Them on Alternate Mornings or Nights

Another option is to apply your niacinamide and acid on alternate mornings or nights. 

So, one night you could apply your niacinamide after cleansing. The next night, you could use your acid. Or this could happen in the mornings, if you prefer.

Again, the one caveat here is that if you are using additional products on top of them, you need to be mindful of pH levels. My general rule is that any products that are more than about 1.0 apart need to be separated by a waiting period.

Option 3: Apply Them 30 Minutes Apart

Your last alternative is to use your niacinamide and acid at the same time, just 30 minutes apart. That way, each product is able to work at its intended pH. You can do this once or even twice a day, depending on your skin type.

When layering products, you always want to be moving in order of lowest to highest pH. So start with the acid, straight after cleansing, since it's going to be around pH 3.0 to 4.0. 

Incorporating a 30-minute wait will give your skin pH a chance to return to normal, about pH 5.5. Then you can apply your niacinamide, which will be around pH 5.0 to 7.0, without having to worry about the niacin conversion. After that, proceed with your hydrators and SPF.

Conclusion

If you've ever wondered whether you can incorporate niacinamide and acid in one skincare routine, rest assured—you definitely can!

While there are a few acid treatments out there that also give you a low dose of niacinamide (like the COSRX AHA and BHA), I do recommend using separate products if you want to see the best results.

Personally, I've noticed brighter skin, faded pigmentation and fewer breakouts from using either The Ordinary or Paula's Choice 10 percent niacinamide serums in addition to my favourite acid, the COSRX BHA. But if you prefer a different niacinamide or acid, that's totally up to you!

The key is to make sure you use them at the right time, in the right order, to keep their pH levels intact (and to avoid the dreaded red flush!).

I hope this tutorial helps you determine how to make the most of these ingredients in your routine. I'd love to hear about your results!

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