Tru Alchemy

Quench Creme

So Jojoba Oil/Macadamia Seed Oil Esters is a jojoba and macadamia oil-derived ingredient that contains fatty acids, triglycerides, and wax esters. It comes to the formula with Squalene,  Phytosteryl Macadamiate (botanical sourced version of cholesteryl ester) and Phytosterols (botanical version of cholesterol) in the ratios found in young, healthy adult skin.  

So the main skill of L22 is barrier repair and skin hydration and the manufacturer did several double-blind, vehicle-controlled studies to show it really works. It compared 3% of L22 with 3% of olive oil or 3% of caprylic/capric triglyceride alone or combined with Ceramide 2 in a vehicle. 60 minutes after the application, barrier recovery was by far the best by the L22 + Ceramide 2 (0.1%) combination, followed by L22 alone, and then by Olive + Ceramide 2 and Olive alone. Skin hydration was measured 4 hours after application and again, the L22 + Ceramide 2 combination performed the best followed by L22 alone. 

Another study compared 3% L22 with 3% petrolatum (the gold standard occlusive agent). After 1 hour, they performed similarly both for barrier repair and skin hydration, but after 2 weeks of use and a 1 week regression period, L22 showed significantly better results. 

So the bottom line is: if barrier repair is something that you are interested in, the skin surface lipids of L22 can definitely be worth a try. Even better, if the formula also contains Ceramide 2. 

So what the heck is a wax ester and why is that important anyway? Well, to understand what a wax ester is, you first have to know that oils are chemically triglycerides: one glycerin + three fatty acids attached to it. The fatty acids attached to the glycerin vary and thus we have many kinds of oils, but they are all triglycerides. Mother Nature created triglycerides to be easily hydrolyzed (be broken down to a glycerin + 3 fatty acid molecules) and oxidized (the fatty acid is broken down into small parts) - this happens basically when we eat fats or oils and our body generates energy from it.

Mother Nature also created wax esters but for a totally different purpose. Chemically, a wax ester is a fatty acid + a fatty alcohol, one long molecule. Wax esters are on the outer surface of several plant leaves to give them environmental protection. 25-30% of human sebum is also wax esters to give us people environmental protection. 

So being a wax ester results in a couple of unique properties: First, jojoba oil is extremely stable. Like crazy stable. Even if you heat it to 370 C (698 F) for 96 hours, it does not budge. (Many plant oils tend to go off pretty quickly). If you have some pure jojoba oil at home, you should be fine using it for years. 

Second, jojoba oil is the most similar to human sebum (both being wax esters), and the two are completely miscible. Acne.org has this not fully proven theory that thanks to this, jojoba might be able to "trick" the skin into thinking it has already produced enough sebum, so it might have "skin balancing" properties for oily skin.

Third, jojoba oil moisturizes the skin through a unique dual action: on the one hand, it mixes with sebum and forms a thin, non-greasy, semi-occlusive layer; on the other hand, it absorbs into the skin through pores and hair follicles then diffuses into the intercellular spaces of the outer layer of the skin to make it soft and supple.

On balance, the point is this: in contrast to real plant oils, wax esters were designed by Mother Nature to stay on the surface and form a protective, moisturizing barrier and jojoba oil being a wax ester is uniquely excellent at doing that.

It's a really promising candidate (see below), but while reading all the goodness about it in a minute, do not forget that derivatives not only have to be absorbed into the skin but also have to be converted to pure vitamin C (ascorbic acid or AA) and the efficacy of the conversion is often unknown. In addition, vitamin C's three magic properties (antioxidant, collagen booster, skin brightener) are all properly proven in-vivo (on real people), but for the derivatives, it's mostly in-vitro studies or in the case of THDA, it's in-vitro and done by an ingredient supplier.

With this context in mind let's see what THDA might be able to do. First, it is stable (if pH < 5), easy to formulate, and a joy to work with for a cosmetic chemist.

Second, because it's oil-soluble, its skin penetration abilities seem to be great. So great in fact, that it surpasses the penetration of pure vitamin C threefold at the same concentration and it penetrates successfully into the deeper layers of the skin (that is usually important to do some anti-aging work). There is also in-vitro data showing that it converts to AA in the skin. 

Third, THDA seems to have all three magic abilities of pure vitamin C: it gives antioxidant protection from both UVB and UVA rays, it increases collagen synthesis (even more than AA) and it has a skin brightening effect by reducing melanogenesis by more than 80% in human melanoma cell cultures.

So this all sounds really great, but these are only in-vitro results at this point. We could find Tetrahexyldecyl Ascorbate mentioned only in one published in-vivo study that examined the anti-aging properties of a silicone formula containing 10% AA and 7% THDA. The authors theorized that the 10% AA is released slowly from the silicon delivery system and probably stays in the upper layer of the skin to give antioxidant benefits, while THDA penetrates more rapidly and deeply and gives some wrinkle-reducing benefits. The study was a small (10 patients), double-blind experiment, and the formula did show some measurable anti-aging results. However, it is hard to know how much pure vitamin C or THDA can be thanked.

Bottom line: a really promising, but not well-proven vitamin C derivative that can be worth a try especially if you like experimenting (but if you like the tried and true, pure vitamin C will be your best bet).

Another advantage of squalane is that it is pretty much compatible with all skin types and skin conditions. It is excellent for acne-prone skin and safe to use even if you have fungi-related skin issues, like seborrhea or fungal acne.

The unsaturated (with double bonds) and hence less stable version of Squalane is Squalene, you can read about it here >> 

Chemically speaking, it is an unsaturated (has double bonds) hydrocarbon (contains only carbon and hydrogen) molecule, that can undergo oxidation. On the pro side, this means that squalene can act as an antioxidant (while its no-double-bond version sister, squalane cannot), but on the con side, squalene is less stable and has a shorter shelf life.

This is probably the main reason why its no-double bond and hence more stable sister, squalane shows up more often on ingredient lists. Read about squalane 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).

To be more specific, both Bakuchiol and retinol upregulate collagen I, III and IV production and downregulate MMP, the evil collagen attacking enzyme in our skin. This means more collagen stays in our skin and we all know that more collagen equals firmer, more wrinkle-free skin.  A 12-week clinical study using a 0.5% Bakuchiol formula with 17 people using it twice a day confirmed a significant improvement in lines and wrinkles, elasticity, firmness and an overall reduction in photo-damage. Also, the test formula was very well tolerated, without any retinol-like side effects. 

What's more, a 2018 double-blind study with 44 people compared 0.5% Bakuchiol with 0.5% retinol cream and found that "bakuchiol is comparable to retinol in its ability to improve photoaging and is better tolerated than retinol". A super promising result after 12 weeks. 

If you are not a daredevil-type who doesn't want to stop using a super well-proven retinol for a newbie like Bakuchiol, we have good news. The two also work very nicely together and Bakuchiol can actually help to stabilize the otherwise unstable and hard to formulate retinol.

And we are still not done, as Bakuchiol shows not only anti-aging properties but also nice anti-acne effects. 1% Bakuchiol seems to be very effective in itself (57% reduction in acne after 6 weeks treatment) and even better when combined with 2% salicylic acid (67% reduction in acne after 6 weeks). We like that Bakuchiol is such a good team player!  The molecule works against acne in multiple ways: It downregulates 5α-reductase (a sebum-controlling enzyme), it is antibacterial (including P. acnes), anti-inflammatory and it inhibits lipid-peroxidation, an evil oxidative process that is recently thought to be a very early trigger in the acne process. 

We feel that this description is becoming very long so we will just mention that Bakuchiol also seems to positively regulate hydration-related genes such as Aquaporin 3 and also shows some melanin-inhibiting properties. 

Overall, we think Bakuchiol is an awesome molecule with lots of promise both for anti-aging and anti-acne. But the proof compared to the well-established superstars is far from solid, so in a skincare routine, we would rather add Bakuchiol next to retinol than straight up replace it. Unless you are a gimme-the-newest-shiny-thing-under-the-sun-type. 

There are also some studies into the use of quercetin as a skin whitening agent, but after some conflicting results, the conclusion is that "quercetin is not effective in cosmetic applications as a whitening ingredient". It also shows minor cytotoxicity when compared to some of its polyphenol derivatives (such as rutin), so quercetin is a good example where more is not better.