Dr. Jetske Ultee

Vitamin A Serum

It's a so-called retinoic acid ester, meaning that it's directly related to retinoic acid. If you've already read our description about retinol or retinyl palmitate, you know that the active ingredient our skin cells can interpret is retinoic acid. Other forms of retinoids have to be converted by our metabolic machinery to do something. That's not the case with HPR.  It binds directly to the retinoid receptors of the skin cells to work its skincare magic. 

The big promise of HPR is that it's similarly active as retinoic acid (no conversion needed, remember) but without the irritation. According to the manufacturer's tests, 24 hours of an occlusive patch with 0.5% HPR resulted in significantly lower irritation than 0.5% retinol.  Also, there was a "dramatic reduction of lines and wrinkles" after applying 0.2% HPR around the eyes twice a day for 14 days.

These results sound sooo promising that we don't blame you if you wanna run out right now and get an HPR formula to slather on your face.  But, before you do, you have to know that the info we have about HPR at the moment is mainly from the manufacturer, whose tests may or may not be accurate or properly designed (such as controlled, double-blind and conducted on an appropriate number of people). 

As HPR is pretty new there isn't that much independent research we could find yet. We found two Italian studies both examining the efficacy of HPR combined with other things (retinol in both cases, and papain in one of them) for the treatment of acne. Both studies found the formulas effective but they contained other things too, so it's hard to judge how well HPR did.

Regarding anti-aging, there is a pretty recent, Estee Lauder sponsored study that compared the in-vitro (not on real human beings but on skin models) collagen-boosting effectiveness of Hydroxypinacolone Retinoate, tretinoin, good old retinol and retinyl palmitate (RP). The results are pretty encouraging showing that  "HPR had greater levels of gene transcription than retinol and RP (RP) at the same concentrations ... however, HPR did not achieve gene transcription levels of ATRA (tretinoin)."  But, a much higher dose might be tolerated from HPR and the highest dose of HPR out-performed tretinoin. Pretty encouraging, though we are very much waiting for a study to confirm all this on real human beings.  

Bottom line: We are really happy to see some innovation happening with retinoids, and we think Hydroxypinacolone Retinoate is a super promising rising star, but it’s not fully proven yet. If you are someone who likes to experiment and try out the newest things, grab your running shoes and try some HPR containing serum now (see product list below :)). If you like the tried and true, however, stick to retinol and tretinoin for now and re-examine the question in a couple of years when (hopefully) more research will be available. 

Are you into Retinoids? Read our shiny description about other members of the retinoid family: 

• Retinyl Propionate: the most promising retinol ester out there
• Retinyl Retinoate: a super interesting retinol-retinoic acid hybrid molecule
• Tretinoin: the FDA-proven, well-known active ingredient
• Retinol: the good old vitamin A molecule
• Retinyl Palmitate: a super common, but our least fav member of the retinoids

So, the triglyceride molecules are the saponifiable part of the oil, and the rest is the unsaponifiable part. In the case of sunflower oil, it's about 1.5-2% of the oil and consists of skin nourishing molecules like free fatty acids (fatty acids not bound up in a triglyceride molecule, it contains mainly (48-74% according to its spec) barrier building linoleic acid), tocopherol (vitamin E) and sterols.

According to manufacturer's info, it's an oily ingredient that not only simply moisturizes the skin but also has great lipid-replenishing and soothing properties. The clinical study done by the manufacturer (on 20 people) found that a cream with 2% active increases skin moisturization by 48.6% after 1 hour, and 34.2% after 24 hours. Applied twice daily for 4 weeks, the study participants had a major improvement in skin dryness, roughness, and desquamation (skin peeling) parameters.

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.