If you’ve been reading this blog long enough or follow me on Instagram, you know my woes with Vitamin C. It’s an incredibly powerful skincare ingredient, yet my skin just doesn’t quite react to it like others do.
Is it the type of vitamin c I’m using? Is it the formula?
If you’re struggling with the same issues, keep reading because this post has everything you need to know about the different types of vitamin c, what they do, and mini reviews on the products featuring these ingredients!
Before we look at all the different forms of vitamin c, let’s take a look at why it’s beneficial for our skin:
Vitamin C Skincare Benefits
- Promotes collagen synthesis. As we get older, the collagen in our skin starts breaking down and the there’s a decrease in production levels, which means we start seeing fine lines, wrinkles, and sagginess!
- Protects from and treats UV damage. While by no means a replacement for sunscreen, vitamin c can protect against the free radicals from UV exposure and reverse some of the damages caused by too much fun in the sun.
- Reduce hyperpigmentation and dullness by decreasing melanin formation. It works even better when paired with other brightening ingredients!
- Is anti-inflammatory. It inhibits the protein complex that begins the inflammation process, making it great at healing acne and preventing post-inflammatory hyperpigmentation (source).
- Promotes a healthy skin barrier. A study found an increase in ceramide levels when vitamin c levels increased as well
Yep, list any of your skincare woes and vitamin c will pretty much takes care of it, plus it has a ton of studies to back up its claims. Now the question is, what are the differences between the various forms, and is one better than another?
Ascorbic acid (AA)
The most well researched form of vitamin c and the most potent. Other forms of vitamin c often need to be converted to ascorbic acid first to achieve the benefits. A couple things to keep in mind:
- It’s notoriously unstable. Exposure to air, light, and heat will cause AA to start oxidizing. Adding in vitamin E and ferulic acid can help stabilize AA, as can using an opaque and airtight container. Formula and packaging is key when using AA!
- It’s water soluble and requires a low pH ( > 3.5) for optimal skin penetration.
- It can be irritating due to the low pH formula it’s in, making it less ideal for those with dry/sensitive skin
- Its potency increases with concentration, starting at 5 % and up to 20%. Anything stronger will not deliver better results.
Ascorbic Acid Product Recommendations
Klairs Freshly Juiced Vitamin Drop – 5%
Despite the clear bottle this never oxidized on me! Very gentle, albeit has a slightly greasy texture that feels more like a dry oil than a typical serum. Full review here.
Cerave Skin Renewing Vitamin C Serum* – 10%
Just as gentle as the Klairs but with a much more elegant water-gel like texture. Also contains barrier supporting ceramides and cholesterol. A great option for combo/oily skin types.
The Inkey List Vitamin C Serum* – 30%
A waterless cream that needs to be mixed with a hydrating serum or moisturizer to minimize irritations, but it’s an incredibly stable formula. It’s also the most effective ascorbic acid serum I’ve tried yet, and one of the most affordable too! Full review here.
La Roche-Posay 10% Pure Vitamin C Serum* 10%
A gel like serum that feels surprisingly gentle and hydrating on the skin. Also contains salicylic acid which I thought was interesting. However it comes in a clear bottle and I’m noticing oxidization after a month into using. Full review here.
Paula’s Choice C15 Super Booster* 15%
Opaque bottle and the classic vitamin e + ferulic acid formula. Has a slightly greasy texture but absorbs well and isn’t irritating or sticky. Didn’t oxidize until I almost finished the bottle. One of the most well-rounded AA products here.
Algenist Blue Algae Vitamin C*
Expensive but just a few weeks of using this and I’ve noticed brightening results already. It’s also quite gentle on the skin and comes in an airtight bottle.
Magnesium Ascorbyl Phosphate (MAP)
This is a stable of vitamin c that needs to be transformed into ascorbic acid by our skin. As a result, it’s not as potent, but also much gentler on the skin.
- Still water soluble but no longer requires a low pH to be efficient.
- Doesn’t absorb as well but does convert into AA in the skin.
- Delivers all the benefits of AA but because it’s weaker, it’s often paired with other antioxidants and brightening ingredients to boost its efficacy.
- One study found that a concentration of at least 10% MAP is required for brightening effects (source).
- Considered a brightening ingredient by the Department of Health in Taiwan, suggesting that enough research was done to in terms of MAP’s brightening properties.
MAP product recommendations
Common Labs Ggultamin C Real Jel Mask*
Contains 10ppm of MAP along with lots of other brightening and soothing ingredients. It’s nourishing without being heavy and leaves my skin soft and plump. Full review here.
Sodium Ascorbyl Phosphate (SAP)
SAP and MAP are very similar in that:
- Both are water soluble and not low-pH dependent
- Both are often paired with other key ingredients to improve efficacy.
- Doesn’t absorb well into the skin, but still has antioxidant and some collagen boosting effects, though less than MAP.
- One study actually found SAP to be even more stable than MAP (source).
- Several studies show that SAP has an antimicrobial effect and can be a good option for treating and preventing acne (source). Don’t forget vitamin c in general is anti-inflammatory, which is also beneficial for acne-prone skin.
SAP product recommendations
Activist Skincare Active Hydration Vitamin C+ Antioxidant Serum*
A beautiful silky serum with plenty of hydrating and soothing ingredients! Gentle on the skin and improves overall skin health with continued usage. Full review here.
Klairs Freshly Juiced Vitamin Drop
In addition to AA it also includes SAP, making it a good option for acne-prone skin.
Orgaid Vitamin C & Revitalizing Sheet Mask*
One of my favorite sheet masks due to its excellent blend of brightening and hydrating ingredients with no fillers. This one really brightens the skin after using!
Ethyl Ascorbic Acid (EAA)
- Aka 3-O-ethyl-L-ascorbic acid, an extremely stable form of vitamin C.
- The conversion rate to AA in the skin is 86%, which is higher than the average 50-60%!
- Several studies have been done on EAA’s brightening effects, which show promising results (source). One study showed that it has superior brightening abilities compared to other vitamin c forms, even AA (source)
- There have been a few reports of allergic reactions to EAA, but in my opinion this is more of a YMMV case than an actual issue with EAA.
EAA products to try
Kiehl’s Clearly Corrective Dark Spot Solution
Has a water-like texture that absorbed instantly into the skin, no irritations whatsoever. Sadly it did little to improve my skin tone or my dark spots, but it’s a highly rated product so it could be worth a try. Full review here.
Hylamide Booster C25 – 25%
A water-free and oil-free serum with just 4 ingredients. Has the same oily slip as the Klairs serum and I didn’t notice any brightening effects.
Ascorbyl Glucoside (AG)
- A water-soluble form of vitamin C that’s more stable than AA (at this point just assume every other vitamin c form is more stable than AA).
- Non-irritating. What else is new?
- Absorbs well and can be converted into AA in our skin, thus delivering all its benefits as well: antioxidant protection, boosting collagen production, and brightening hyperpigmentation
- Considered a brightening ingredient by the Department of Health in Taiwan, suggesting that AG’s brightening properties are well studied.
- One study showed that AG significantly reduced hyperpigmentation when used with an absorption enhancer like ultrasound radiation (source) and another study showed the same results when used with a full-face iontophoresis mask (source).
AG product recommendations
INKEY List 15% Vitamin C and EGF Brightening Serum*
Watery texture, easy to absorb, no sticky finish. Contains EFG for an anti-aging boost but I didn’t see much results in terms of brightening. A great affordable + gentle antioxidant serum though!
Ascorbyl Palmitate (AP)
- A fat soluble form of vitamin c that penetrates the skin more easily than other forms (source).
- Doesn’t convert well into AA, so products would need a high % of AP to see results.
- More stable than AA but less stable than the other forms
- Offers antioxidant protection but also causes cell membrane damage when exposed to UVB rays.
- Can help control sebum production when used with SAP, making it a good option for oily and acne-prone skin (source).
Tetrahexyldecyl Ascorbate (TA)
- Aka VC-IP, Ascorbyl Tetraisopalmitate, or THD Ascorbate.
- Fat soluble, gentle, and very stable. It can also penetrate into the deeper layers of the skin with an absorption rate that’s 3x better than AA.
- Converts to AA and offers all 3 benefits: antioxidant protection, collagen production boost, brightening
- Several clinical trials showed significant improvement in skin texture and tone after using products featuring (not not limited to) ATIP (source , source, source).
- It can stimulate the production natural moisturizing factors, which allows our skin to better to absorb moisture from the body, keeping it well hydrated (source).
- One study found that ATIP is actually better at increasing collagen synthesis than AA (source).
ATIP product recommendations
Peter Thomas Roth Potent-C Power Serum* – 20%
Also features 3% Vitamin E + 2% Ferulic Acid for some serious antioxidant action. It has a emulsion-like texture that absorbs quickly into the skin, leaving minimal shine and stickiness. Overall skin tone seems to have improved since using this.
Sunday Riley C.E.O. Glow
A facial oil featuring turmeric extract, raspberry+ cranberry + pomegranate seed oils. As a result this gives you antioxidant benefits plus the extra moisture oils provide. While I didn’t notice significant brightening results, I lovedhow using it always made my skin juicy and glowy. Would repurchase.
Aminopropyl Ascorbyl Phosphate (AAP)
- Has a better absorption rate than AA
- Shown to boost collagen production.
- 0.5% AAP reduced hyperpigmentation age spots by 29-33% and reduced number of wrinkles by 23% after 8 weeks (source)
- Can add antioxidant protection as part of sunscreen formulas
Kudos to you if you’ve read through all that, because I know that was a lot of info, but if you haven’t, here’s a quick summary:
- Formula is key when selecting a vitamin c product. For AA-based products, the pH needs to be < 3.5. For all other forms, you’ll want to see it in a mix with other antioxidants and beneficial ingredients.
- The % matters! 5-20% is optimal for AA, and remember that other derivatives need to be converted to AA first, so if you’re getting a peanut amount of that, you probably aren’t getting any of the vitamin c benefits.
- When it comes to potency, you can’t beat AA. However, you’ll want to weight the pros and cons to see if it’s really the right form for your skin type and skincare habits. Sensitive skin will want to try the other gentler forms, or at least start with a very low % of AA.
- Oily and acne prone skin can consider SAP and AP for its anti-microbial and sebum control properties.
- Look for EAA, AG, or MAP if you want to brighten your skin tone, as they have specific studies done in regards to their brightening properties. I prefer AG, but YMMV.
- Always wear sunscreen, especially if you use AA as that can make your skin more sensitive!
Hope you found this post helpful, and let me know which vitamin c product(s) you swear by!