Vasanti

Brighten Up! Glow Boosting Serum

Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying. 

One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time. 

All in all, arbutin is one of the better-known skin brightening agents, that's probably worth a try if pigmentation is an issue for you.

Leafy green vegetables, walnuts, flax seeds and fish oils are rich sources of ALA and if you are not eating a lot from these, supplementing with fish oil is a pretty good idea backed by research. It is a good idea both in terms of general health benefits as well as potentially improving inflammation-related skin issues such as atopic dermatitis or acne.

As for using ALA topically, we have to say that its role and effects seem to be less direct than with LA. ALA's main role in the skin appears to be modulating the immune response of the epidermis. This is probably helpful for inflammatory skin diseases but most studies examine ALA as an oral supplement and not when applied topically. One exception, we could find, is a study that found that topically applied ALA has nice spot-fading abilities.

To be honest, it seems to us that oral supplementation of ALA is more important than smearing it all over your face. However, that is not to say that topical ALA is a bad thing, it is a good thing. It is a skin-identical ingredient, it is probably moisturizing and anti-inflammatory but its topical effects are less established than that of fellow omega fatty acid, linoleic acid. 

As for linoleic acid and the skin, LA is a really important little guy found naturally in our skin. It is the most abundant fatty acid in the epidermis and it serves as a structural precursor for important skin lipids called ceramides. Knowing this, it will not come as a surprise that Linoleic acid has a central role in the structure and function of stratum corneum permeability, aka healthy skin barrier.  LA deficiency leads to an impaired more permeable skin barrier and the topical application of LA-rich sunflower oil can fix this issue rapidly (while oleic-rich olive oil did not have the same barrier repairing effect).

LA is not only important for dry, barrier damaged skin types but also for acne-prone skin. Research shows that problem skin has lower levels of linoleic acid (and higher levels of oleic acid) than normal skin. So LA-deficiency in the skin seems to be connected not only to an impaired skin barrier but also to acne and smearing LA all over your face might help with your problem skin. A double-blind study using a 2.5% LA gel for 4 weeks found a 25% reduction in the size of microcomedones, the tiny blocked pores that can later lead to acne.

If that was not enough, we have one more thing to report about LA.  It lightens hyperpigmentation (aka UVB caused sun spots) both by blocking the melanin production of melanocytes (the skin cells that make the pigment melanin) and by enhancing the desquamation of melanin pigment from the upper layers of the skin.

Overall, linoleic acid is a multi-functional skin goodie with barrier repairing, acne-reducing, and skin-lightening magic abilities. It's a nice one to spot on the ingredient list pretty much for any skin type. 

What's the problem?

Firstly, it's stability is only similar to that of pure ascorbic acid (AA), which means it is not really stable. A great study in the Journal of Cosmetic Dermatology compared a bunch of vitamin C derivatives and this derivative was the only one where the study said in terms of stability that it's "similar to AA". Not really that good.

Second, a study that examined the skin absorption of vitamin C found that ascorbyl palmitate did not increase the skin levels of AA. This does not mean that ascorbyl palmitate cannot penetrate the skin (because it can, it's oil soluble and the skin likes to absorb oil soluble things) but this means that it's questionable if ascorbyl palmitate can be converted into pure Vit C in the skin. Even if it can be converted, the palmitate part of the molecule is more than the half of it, so the efficacy will not be good and we have never seen a serum that contains a decent (and proudly disclosed) amount of AP.  We are highly skeptical what effect a tiny amount of AP has in a formula.

Third, another study that wanted to examine the antioxidant properties of AP was surprised to find that even though AP does have nice antioxidant properties; following UVB radiation (the same one that comes from the sun) it also promotes lipid peroxidation and cytotoxicity. It was only an in-vitro study meaning that it was done on cell cultures and not on real people, but still, this also does not support the use of AP too much. 

The only good thing we can write about Ascorbyl Palmitate is that there is an in-vitro (made in the lab, not on real people) study showing that it might be able to boost collagen production.

Regarding the skin-brightening properties of pure vitamin C, this is another magic property AP does not have, or at least there is no data, not even in-vitro, about it.

Overall, Ascorbyl Palmitate is our least favorite vitamin C derivative. It is there in lots of products in tiny amounts (honestly, we do not really understand why), however, we do not know about any vitamin C serum featuring AP in high amounts. That is probably no coincidence. If you are into vitamin C, you can take a look at more promising derivatives here. 

In spite of this, if you search for "hyaluronic acid vs sodium hyaluronate" you will find on multiple places that sodium hyaluronate is smaller and can penetrate the skin better. Chemically, this is definitely not true, as the two forms are almost the same, both are polymers and the subunits can be repeated in both forms as much as you like. (We also checked Prospector for sodium hyaluronate versions actually used in cosmetic products and found that the most common molecular weight was 1.5-1.8 million Da that absolutely counts as high molecular weight).

What seems to be a true difference, though, is that the salt form is more stable, easier to formulate and cheaper so it pops up more often on the ingredient lists. 

If you wanna become a real HA-and-the-skin expert you can read way more about the topic at hyaluronic acid (including penetration-questions, differences between high and low molecular weight versions and a bunch of references to scientific literature).

Also, if your skin is sensitive, fragrance is again not your best friend. It’s the number one cause of contact allergy to cosmetics. It’s definitely a smart thing to avoid with sensitive skin (and fragrance of any type - natural is just as allergic as synthetic, if not worse!).