is sodium ascorbyl phosphate an effective form of vitamin C?

Got oily skin and your Vitamin C serum makes you breakout? You’re not imagining things. There are lots of different types of Vitamin C out there, but only one is suitable for oily skin: Sodium Ascorbyl Phosphate (or SAP, for short).

I usually recommend the original form of Vitamin C, L-Ascorbic Acid, to all my clients. When it comes to fighting wrinkles and fading away dark spots, it’s the most effective. But it has its fair share of side effects. It’s irritating in high concentrations. It loses effectiveness when you get the pH wrong or you expose it to light and air. And, there’s anecdotal evidence it makes oily, acne-prone skin break out.

Sodium Ascorbyl Phosphate is a derivative of Vitamin C that doesn’t have any of these drawbacks. But what makes it stand out from all the other forms of Vitamin C is a different superpower. Sodium Ascorbyl Phosphate is the only form of Vitamin C that can fight acne and help it heal faster.

If you have oily skin, make the switch now. But what if you don’t? Is Sodium Ascorbyl Phosphate the best form of Vitamin C for other skin types too? Let’s find out:

What Is Sodium Ascorbyl Phosphate?

Sodium Ascorbyl Phosphate is a water0soluble derivative of L-Ascorbic Acid, the pure form of Vitamin C. It’s made by combining Ascorbic Acid with a phosphate and a salt, two compounds that work with enzymes in skin to split the ingredient and release pure ascorbic acid into your skin.

For clarity, L-Ascorbic Acid is the bioactive form of Vitamin C, which means it’s the form your skin can immediately use. Sodium Ascorbyl Phosphate must be converted into L-Ascorbic Acid by enzymes on your skin. But delivering it this way means it’s gentler and better tolerated by skin.

Benefits Of Sodium Ascorbyl Phosphate For Skin: What Does It Do?

Sodium Ascorbyl Phosphate is a form of Vitamin C, one of the most versatile antioxidants in skincare. Here’s everything it does for your skin:

1. It Prevents Premature Aging

Vitamin C is a powerful antioxidant. “It works to combat the effects of UV damage by scavenging the free radicals that cause DNA changes and lead to signs of photoaging,” says dermatologist Michele Farber, M.D.

Here’s how it works. Unprotected sun exposure, pollution, and even metabolic processes like breathing cause free radicals, nasty molecules that destroy collagen, elastin, cellular DNA and everything else that keeps your skin younger-looking. By neutralising these free radicals, Vitamin C helps your skin age more slowly than it otherwise would.

2. It Boosts Collagen

Did you know that Vitamin C is essential for the synthesis of collagen, the protein that keeps your skin firm?  Studies show that it “has an antiaging effect by increasing collagen synthesis, stabilizing collagen fibers, and decreasing collagen degradation.” When your skin has all the collagen it needs, it’s firmer and looks younger. Skin doesn’t sag as quickly and wrinkles take a lot longer to form. But, it’s less effective than other forms of Vitamin C, like Magnesium Ascorbyl Phosphate at this.

3. It Brightens Skin

Vitamin C doesn’t just fight wrinkles. It fades away dark spots too. A 2011 study shows that Vitamin C inhibits tyrosinase, the enzyme that produce melanin (the pigment that gives your skin its natural colour). What does this mean? Dark spots appear when your skin produces way more melanin than it should. Vitamin C slows down its production, so your skin stops pumping out the extra pigment. Overtime, your skin goes back to its original shade.

Vitamin C works at fading away dark spots, but few studies have been done on Sodium Ascorbyl Phosphate specifically. In their absence, Paula Begoun said it best: “This form of vitamin C is potentially effective for brightening an uneven skin tone, although there isn’t much research supporting its use for this purpose over other forms of vitamin C.” So yes, it works, but not necessarily better than L-Ascorbic Acid. It’s less effective, remember?

4. It Helps Treat Acne

A study published in the International Journal of Cosmetic Science shows that Sodium Ascorbyl Phosphate can treat acne vulgaris. How? Acne is caused by two major factors:

  • Bacteria: Proprionibacterium Acnes, or P.Acnes for short
  • Lipid oxidation: When your sebum oxidises, your skin becomes inflamed

Sodium Ascorbyl Phosphate deals with both. 1% of SAP reduces the amount of P.Acnes on your skin, while 5% prevents lipid oxidation (by 40%!) in the first place. The scientists said it works a lot better than many other anti acne treatments out there.Studies have shown that SAP works better than 5% benzoyl peroxide, 1% clindamycin phosphate, and 0.1% adapalene (a.k.a differin). And, unlike other treatments, it has no side effects!

A 2009 study found that  5% SAP reduced the inflammatory lesions by 20.14% and 48.82% within 4 and 8 weeks respectively. It works even better when used together with retinol. Together, they improved lesions by 29.28% after 4 weeks and 63.10% after 8 weeks!

Related: 3 Little-Known Anti-Acne Ingredients For Clear Skin

Sodium Ascorbyl Phosphate VS L-Ascorbic Acid: Which One Is Better?

I know what you’re thinking. What’s the point of using a derivative if it’s converted to the original anyway? And doesn’t that make it less effective?

Yes. “I think of l-ascorbic acid as the equivalent of lifting a ten pound weight, and sodium ascorbyl phosphate as a five pound weight,” says Mona Gohara, M.D., associate clinical professor of dermatology at Yale School of Medicine. “It’s lighter and less intense, though still beneficial.” If it’s less effective, why use it? Because it’s gentler on the skin. If you have sensitive skin that can’t tolerate L-Ascorbic Acid, you may be able to use Sodium Ascorbyl Phosphate without issues.

Plus, L-Ascorbic Acid is highly unstable and goes bad quickly when exposed to light, air, and water. “Sodium ascorbyl phosphate is considered to be one of the more stable forms of the vitamin and is light-, oxygen-, and water-stable,” says Chicago-based dermatologist Jordan Carqueville, M.D. Even though it’s less effective, it never loses potency overtime like L-Ascorbic Acid does.

Sodium Ascorbyl Phosphate is also a better choice for acne-prone skin for two reasons. For starters, it helps reduce the amount of acne bacteria on your skin. No other form of Vitamin C does this. The other reason? Although there is no scientific studies that shows L-Ascorbic Acid causes acne, I have many clients with oily skin who experience small breakouts when they use this active. When I tell them to switch to Sodium Ascorbyl Phosphate, they disappear.

Related: Types Of Vitamin C Used In Skincare

Side Effects Of Sodium Ascorbyl Phosphate 

L-Ascorbic Acid, the pure form of Vitamin C, can be irritating in high concentrations. Sodium Ascorbyl Phosphate is much gentler, so even sensitive skin can better tolerate it. Still, everyone’s skin is different. If you have sensitive skin that reacts to everything and anything, do a patch test before using it.

How To Use It 

By fighting free radicals, Vitamin C boosts the effectiveness of your sunscreen. For best results, use it in the morning, right after cleansing but before moisturiser/sunscreen. If you want to use a hyaluronic acid serum, use it after the Vitamin C serum.

How Often Should You Use It?

You can use it every single day, once a day, in the morning. In the rare case that you’re experiencing any irritation, cut back to twice a week and build up frequency from there slowly.

Who Should Use It?

Sodium Ascorbyl Phosphate is the only form of Vitamin C that can fight acne, so it’s best suitable for oily and acne-prone skin. It’s also a good choice for sensitive skin that can’t tolerate L-Ascorbic Acid.

What Ingredients Does It Work Well With?

Like all forms of Vitamin C, Sodium Ascorbyl Phosphate works better when paired with other antioxidants. Each antioxidant only fights one or two types of free radicals. The more you use, the more free radicals you neutralise. Vitamin C works particularly well when paired with Vitamin C and Ferulic Acid.

What Are The Best Products With Sodium Ascorbyl Phosphate?

Unfortunately, it’s hard to come across skincare products with sodium ascorbyl phosphate. Your best best is below:

  • Artnaturals Vitamin C Serum ($12.99): A hydrating Vitamin C serum for oily skin, it fights free radicals, brightens your complexion, and reduces sebum oxidation to keep acne at bay. Available at Target.
  • CocoKind Vitamin C Serum ($19.99): A super hydrating serum with hyaluronic acid and aloe vera to deeply hydrate skin and fight wrinkles at the same time. It has a touch of citrus essential oil to make it smell good, but it can irritate sensitive skin. If it doesn’t bother you, no reason not to use it. Available at Cocokind and Ulta.
  • Derma E Vitamin C Radiance-Boosting Renewing Moisturizer ($23.95): Even though it’s loaded with moisturising oils, it has a lightweight texture that sinks in quickly. Thanks to Vitamin C, it also brightens skin. Available at Derma E, iHerb, and Ulta.
  • Mad Hippie Vitamin C Serum ($33.99): My fave serum with Sodium Ascorbyl Phosphate, it features its fair share of antioxidants and soothing ingredients, like ferulic acid and chamomile, to prevent wrinkles and soothe irritations. Available at iHerb and Ulta.
  • Paula’s Choice Resist Anti-Aging Clear Skin Hydrator ($37.00): A lightweight, gel lotion loaded with antioxidants to hydrate oily skin and fight premature wrinkles. Available at Cult Beauty, Paula’s Choice, and SpaceNK.
  • Strivectin Super-C Retinol Brighten & Correct Vitamin C Serum ($72.00): This brightening serum contains 3 forms of Vitamin C (including Sodium Ascorbyl Phosphate) plus retinol to fight wrinkles and fade away dark spots. Available at Boots, Dermstore, Sephora, and Strivectin.

Need help to create a skincare routine that tackles both acne and aging? Click on the image below to subscribe to my newsletter and receive the “Acne + Aging Skincare Routine” cheatsheet:

The Bottom Line

Sodium Ascorbyl Phosphate isn’t as effective as pure Vitamin C (L-Ascorbic Acid) at brightening skin and fighting premature aging. But, it can treat acne, making it the best form of Vitamin C for oily and acne-prone. And it’s gentler than pure Vitamin C, so even sensitive skin can use it.