Aveda

Scalp Solutions Refreshing Protective Mist

One of the biological activities of the centellosides is to be able to stimulate GAGs  (glycosaminoglycans - polysaccharides that are part of the liquidy stuff between our skin cells), and especially hyaluronic acid synthesis in our skin. This is probably one of the reasons why Centella Asiatica Extract has nice skin moisturizing properties that was confirmed by a 25 people, four weeks study along with Centella's anti-inflammatory effects.

Madecassoside can also help in burn wound healing through increasing antioxidant activity and enhancing collagen synthesis. Asiaticoside was shown to increase antioxidant levels on rats skin when applied at 0.2%. 

Centella Asiatica also often shows up in products that try to treat cellulite or striae. Of course, it cannot make a miracle but it might have some effect via regulating microcirculation and normalizing the metabolism in the cells of connective tissues. 

Bottom line: Gotu Kola is a great plant ingredient with proven wound healing, anti-inflammatory, and antioxidant properties. Nice to spot on any ingredient list.  

Second, still according to Estee Lauder research but now from 2012 the ingredient has anti-microbial and anti-inflammatory properties and holds promise in the treatment of acne and rosacea. For the former one 5% was needed to show effectiveness, but for reducing skin sensitivity already 1% showed results. 

The anti-acne effect is confirmed also by US manufacturer, Barnet, that says that Lactobacillus ferment is helpful in killing harmful bacteria and creating a healthy balanced microflora. Compared to well-known anti-acne and anti-inflammatory salicylic acid the probiotic worked faster at reducing the size and redness of acne lesions. 

It also goes by the trade name Leucidal Liquid SF and can serve in the formula as a natural preservative. 

Bottom line: It’s not the most proven ingredient (yet) but definitely a very promising one especially if you have sensitive skin, acne or rosacea.  

The key skill of Ectoin is protection that applies also to the skin. Its main mode of action is binding water molecules (aka kosmotropic) and creating hydro complexes. These complexes then surround important biomolecules (e.g. cells, proteins, enzymes) and form a stabilizing hydration shell around them. 

This protection mechanism means good things when it comes to our skin: Ectoin has antioxidant, anti-inflammatory, pollution& light protecting, skin hydrating, barrier repairing as well as anti-aging properties. 

A placebo-controlled 10-person study examined a four-week treatment with 0.5% Ectoin in the crow's feet area and found a significant anti-wrinkle effect (-19% mean wrinkle depth) in 100% of the participants. Another double-blind, placebo-controlled clinical study with 24 participants used a 2% Ectoin cream twice a day for 4 weeks and found an improvement in all of the measured parameters, such as wrinkle volume, skin scaling, roughness, and elasticity. 

Another remarkable property of Ectoin is protecting the epidermal immune cells called Langerhans cells from UV damage. 0.3% and 0.5% Ectoin cream was used twice a day for 14 days on the forearm and then irradiated with 1.5 MED UV (one and a half times the UV dose that causes detectable redness). While the untreated, UV-stressed area showed a 40% decrease in viable Langerhans cells, 0.5% Ectoin showed 100% protection (and 0.3% showed ~95% protection). 

The soothing efficacy is also backed up by multiple in-vivo studies. A 20-person study compared 1% Ectoin cream to 0.25% hydrocortisone treatment on surfactant irritated skin and found similar effectiveness in reducing skin redness.  Another study with 23 females with sensitive skin found that a 1% Ectoin cream helped to tolerate a 0.5% or 1% retinol treatment much better.  

A tiny, 5-person study examined the long-term (7 days) skin hydration effect of 1% Ectoin. During the study, hydration levels increased up to 200% compared to placebo, and even 7 days after stopping the treatment hydration status was largely preserved. Higher concentration (5-7%) Ectoin treatments are also used as OTC medical products for the treatment of eczema or atopic skin. 

The anti-pollution magic properties are also well-established and Ectoin is currently the only anti-pollution active ingredient approved for use in medical products (e.g. inhalation solutions) in Europe. Clinical studies showed a reduction of inflammations in human lungs of patients with COPD (a pulmonary disease) and pollution-induced asthma. But coming back to the skin, Ectoin protects both from PMs (Particulate Matters, including ultrafine) as well as PAHs (Polycyclic Aromatic Hydrocarbons) and heavy metals. 

If that weren't enough, Ectoin is also shown to protect the skin from blue and visible light, and pigmentation resulting from environmental stress (think UV, pollution, oxidative stress). 

All in all, we think Ectoin is one of those under-the-radar actives that deserves more hype than it is currently getting. As an amazing all-around skin protectant, it is a useful addition to any skincare routine. 

Our intro did get pretty big after all (sorry for that), so let's get to the point finally: sunflower oil - similar to other plant oils - is a great emollient that makes the skin smooth and nice and helps to keep it hydrated. It also protects the surface of the skin and enhances the damaged or irritated skin barrier. Leslie Bauman notes in Cosmetic Dermatology that one application of sunflower oil significantly speeds up the recovery of the skin barrier within an hour and sustains the results 5 hours after using it.

It's also loaded with fatty acids (mostly linoleic (50-74%)  and oleic (14-35%)). The unrefined version (be sure to use that on your skin!) is especially high in linoleic acid that is great even for acne-prone skin. Its comedogen index is 0, meaning that it's pretty much an all skin-type oil. 

Truth be told, there are many great plant oils and sunflower oil is definitely one of them.

Other than that, ginger also contains moisturizing polysaccharides, amino acids, and sugars, and it is also quite well known to increase blood circulation and have a toning effect.

Last but not least, Ginger also has some volatile, essential oil compounds (1-3%). Those are mostly present in ginger oil, but small amounts might be in the extract as well (around 0.5% based on manufacturer info). 

L-PCA is not only there to hydrate the skin, but it also helps to increase the efficacy and bioavailability of zinc. An in-vivo (done on real people) test done by the manufacturer shows that Zinc PCA reduces sebum production statistically significantly after 28 days of application (1% was used in the test), and in-vitro (made in the lab) measurements show that Zinc PCA has strong anti-microbial activity against P. acnes (between 0.1-0.25%) and other bacterial strains.

If that would not be enough there is also a 2011 research paper saying that based on in-vitro (made in the lab, not on real people)  findings Zinc PCA might be a promising anti-aging active that helps with the production of type I collagen (and we all know more collagen = firmer skin). 

All in all, definitely a goodie for oily, acne-prone skin. 

A well-known thing about Caffeine is that it improves the microcirculation of the blood vessels. Though conventional wisdom and anecdotal evidence says that this property is helpful for dark under-eye circles and puffy eyes, we have to mention that the double-blind research we have found about a 3% caffeine gel concluded that "the overall efficacy of the selected caffeine gel in reducing puffy eyes was not significantly different from that of its gel base."  But you know, the proof is in the pudding.

Another thing Caffeine is used for in body care products is its anti-cellulite effects. In theory, it can speed up the lipolysis process (the "fat burning"  by our cells) and stimulate the draining lymph system that might lead to the improvement of cellulite. But here again, the evidence that it actually makes a measurable, let alone visible,  improvement on actual human beings is limited (we could find only some animal skin studies or caffeine being combined with other actives). 

Last, but not least, we have to write about caffeine and hair growth. The theory is that it can inhibit the activity of the 5-α-reductase enzyme that plays an important role in hair loss and allows a renewed growth phase of the hair. We have found some recent and promising research to back this up. A 2017 study compared a 0.2% caffeine liquid with a 5% Minoxidil  (an FDA approved active to treat baldness) solution and found that  "a caffeine-based topical liquid should be considered as not inferior to minoxidil 5% solution in men with androgenetic alopecia", or English translation means that the caffeine liquid was pretty much as good as the FDA-approved Minoxidil stuff. Not bad!

Overall, we think that caffeine is a very versatile and biologically active ingredient. Even though some of its effects are more hyped up than backed up, it is still a nice to have on many ingredient lists. 

There is also some research showing that citric acid with regular use (think three months and 20% concentration) can help sun-damaged skin, increase skin thickness and some nice hydrating things called glycosaminoglycans in the skin. 

But according to a comparative study done in 1995, citric acid has less skin improving magic properties than glycolic or lactic acid. Probably that’s why citric acid is usually not used as an exfoliant but more as a helper ingredient in small amounts to adjust the pH of a formulation. 

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!). 

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

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.  

As with all fragrance ingredients, citronellol can also cause allergic contact dermatitis and should be avoided if you have perfume allergy. In a 2001 worldwide study with 178 people with known sensitization to fragrances citronellol tested positive in 5.6% of the cases.

There is no known anti-aging or positive skin benefits of the ingredient. It’s in our products to make it smell nice. 

Other than having a good safety profile and being quite gentle to the skin it has some other advantages too. It can be used in many types of formulations as it has great thermal stability (can be heated up to 85°C) and works on a wide range of pH levels (ph 3-10). 

It’s often used together with ethylhexylglycerin as it nicely improves the preservative activity of phenoxyethanol.

BTW, it’s also a food preservative and even has an E number, E202.