Ethique Hydrating Conditioner Concentrate Bloom Versus Ethique Curliosity Co-Wash and Conditioner Bar

It is effective at low concentrations (<0.6%). Clinical studies have found it to be non-irritating, non-sensitizing, and non-photosensitizing.

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

The EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

Fresh linalool is a weak sensitizer but air exposure turns some of it into hydroperoxides, which are strong sensitizers. Those oxidation products are the actual allergy concern.

Patch-test clinics see positive reactions to linalool hydroperoxides in about 4% to 12% of dermatitis patients depending on country and test concentration.

Resassuringly, one analytical study found hydroperoxide levels in real fragranced products to be orders of magnitude below what induced sensitization in animal studies with no evidence of oxidation building up during normal storage.

The practical takeaway is that linalool is fine for most people but worth avoiding if you have a confirmed fragrance contact allergy or a badly compromised barrier.

Products stored a long time after opening are also the high-risk scenario since that is when oxidation happens.

The scent of linalool is described as floral, spicy tropical, and citrus-like.

It has a very saturated profile (stearic acid ~34 to 36%, oleic acid ~30 to 40%, and palmitic acid ~24 to 29%) that makes it a strong occlusive: it sits on top and slows water escaping from skin.

Concentration data shows that it can show up anywhere from a few percent in lotions up to 100% in balms, and the FDA lists cocoa butter as an OTC skin protectant active at 50-100%.

The CIR has reviewed it and concluded it to be safe as used in cosmetics.

This is one of the ingredients with a comedogenic score of 4/5 from the rabbit ear test. Just know that a later human study did find that finished products containing high-comedogenic ingredients like cocoa butter did not increase microcomedone formation.

The fair call here is that this ingredient is most likely fine on body or low-percentage formulas, but can potentially be riskier as a heavy leave-on facial product if you break out easily.

Cocoa butter may not be fungal acne safe; it is a triglyceride of C16-18 fatty acids that the Malassezia yeast can metabolize.

Allergies to cocoa butter are rare and uncommon, but a few cases have been documented (mostly in cases where the person ate chocolate). So if you have a tree nut allergy, be sure to patch test or avoid.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!