As I Am Rosemary Water Versus As I Am Dry & Itchy Scalp Care Water

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

At higher doses or for those with sensitive skin, methol-type cooling can quickly turn into burning/irritation. It can also trigger irritant dermatitis or even allergic contact dermatitis. In a large patch-test dataset, peppermint oil had a low but positive rate for this.

In cosmetics, Cosmetic Safety Reviews (CIR) concludes that peppermint oil is safe to use when formulated to be non-sensitizing with some restrictions; for instance, pulegone, a naturally occurring component of peppermint oil, should not exceed 1%.

Since peppermint oil contains fragrance allergens such as limonene, linalool, and menthol, it can be sensitizing for those with rosacea, eczema, a broken skin barrier, or just sensitive skin in general.

In Japan, this ingredient is known as Hakka Yu.

They work by fitting perfectly into your stratum corneum's lipid matrix since they're structurally similar to cholesterol. Here, they reinforce your skin's barrier.

One small in vivo human study showed topical soybean phytosterols sped up barrier recovery within three days on tape-stripped skin.

Broader research credits them with:

Formulation use typically sit under 5%.

Testing in soy-allergic subjects found no sensitization signals, but be sure to patch test if you are unsure or have existing allergies.

On the emulsifier side, it keeps your formula smooth and well-mixed by playing peacekeeper for ingredients that don't naturally get along (like oil and water).

Because it has a C12 (lauric acid) fatty acid chain, this ingredient can potentially feed the Malassezia yeast that causes fungal acne. The Malassezia yeast prefers esters with C11-C24 fatty acids.

This ingredient is an ester of lauric acid and Polyglycerin-10.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

A perk of this ingredient is that it leaves skin feeling soft and silky after rinsing. This is why you'll even see it in baby washes.

Another perk?
The lauric acid backbone gives it mild antimicrobial activity and lauric acid itself has been shown to suppress acne-causing bacteria in lab studies.

In 2023, scientists took a close look at how SLL behaves and found it can break apart the fatty outer layers of cells. This is basically why it cleans well and can fight off certain microbes.

The Cosmetic Ingredient Review (CIR) Expert Panel has reviewed it and concluded it's safe as used.

A 2017 survey showed concentrations up to 10% are used in rinse-off cleansers and roughly 0.5-5% being typical in skincare.

Animal and reconstructed-skin testing found it to be non-irritating at 10%, and it's well tolerated even on sensitive skin. The only caveat is to patch test if you have a lactic acid allergy.

As a lactylate salt used at low co-emulsifier concentrations, this ingredient is less likely to break down and release free lauric acid on skin. This ingredient is fungal acne safe.

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!