La vie en rose

Blue Chamomile

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.

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. 

Regarding skincare and tea tree oil, its most well-known effect is probably being a well established anti-acne ingredient. Multiple studies confirm that TTO is effective against the evil acne-causing bacteria called P. acnes and the effectiveness of 5% TTO gel is comparable to the gold standard anti-acne treatment, 5% Benzoyl Peroxide lotion. You need to be a bit more patient with TTO, though, as its effects come slower but also with fewer side effects.

Regarding TTO and sensitive skin, we say that you should be careful. Even if your skin is not sensitive you should never put undiluted TTO on your skin. Luckily, it contains only very small amounts of the common allergens (such as limonene), but irritant and allergic reactions still happen, especially by oxidation products that occur in older or not properly stored oil.  So if you have some pure TTO at home, know that storage matters, keep it in a cool, dry, dark place and use it up in a reasonable amount of time.

Overall, we do not often give a goodie status to essential oils, but we feel that TTO's unique antibacterial and anti-acne properties with its minimal allergen content warrant an exception. If your skin is acne-prone, TTO is something to experiment with.

Another pro is that lavender oil has some nice antimicrobial and antibacterial properties. It also has some local pain relieving and muscle relaxing magical powers. Lavender oil is also often claimed to have anti-inflammatory properties. We have found a study confirming this but it was the essential oil of the leaves and not the much more commonly used flowers and the two differ in their main chemical compounds very much. (The main components of the flower essential oil are linalyl acetate and linalool [around 80% the two together] while it is 1,8-Cineole [around 65%] in the essential oil of the leaves.)

Now, let us look at the cons: similar to a bunch of other essential oils, the main components of lavender oil are potentially irritating fragrant components. The two main components are linalyl acetate (about 50%) and linalool (about 35%) and both autoxidise on exposure to the air forming strong contact allergens. To make things even worse, lavender oil seems to be cytotoxic from concentrations as low as 0.25% (concentration up to 0.125% were ok). 

There is also an often cited Japanese study that made patch tests with lavender oil for 9 years and found a huge increase in lavender oil sensitivity in 1997 (from 1.1% in 1990 to 8.7% in 1997 and 13.9% in 1998). This was the year when using dried lavender flowers in pillows, wardrobes, and elsewhere became fashionable in Japan, so it seems that increased exposure to lavender results in increased risk of sensitivity.

Overall, it makes us sad to write bad things about such a lovely plant, but when it comes to skincare, you will be better off without lavender. 

Limonene's nr1 function is definitely being a fragrance component, but there are several studies showing that it's also a penetration enhancer, mainly for oil-loving components.

All in all, limonene has some pros and cons, but - especially if your skin is sensitive - the cons probably outweigh the pros.  

A study made in the UK with 483 people tested the allergic reaction to 3% oxidised linalool and 2.3% had positive test results.