Kiehl's Amino Acid Shampoo

You'll most likely find this ingredient in cleansers where it is used to create a gel-like texture. As an emulsifier, it also prevents ingredients from separating.

There is much debate on whether this ingredient is comedogenic. The short answer - comedogenic ratings don't tell the whole story. Learn more about comegodenic ratings here.

The concensus about this ingredient causing acne seems to be divided. Research is needed to understand if this ingredient does cause acne.

Scrubs may use salt as the primary exfoliating ingredient.

Not only does it help exfoliate the skin, it helps strengthen the skin's barrier. When applied, lactic acid helps the skin create ceramides.

Lactic acid is an over-the-counter chemical exfoliant that comes from the fermentation of lactose — a carbohydrate found in milk.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Read more about some other popular AHA's here:

For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.

The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.

For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.

One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.

Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.

Parfum can also be used to mask or cover an unpleasant scent.

The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.

This ingredient is considered an organic alcohol and commonly added into both cosmetics and foods.

Those with sensitive skin or conditions may develop a rash when using this ingredient.

Unlike AHAs which are water soluble, Salicylic Acid is oil soluble. This means that it's able to exfoliate the inside of pores and reduce blackheads.

Concentrations of 0.5-2% are recognized by the U.S. FDA as an over-the-counter topical acne product.

It can cause irritation and/or dryness if one's skin already has a compromised moisture barrier, so it's best to focus on repairing that before introducing a Salicylic Acid into your routine.

In general, Salicylic Acid is a great ingredient for oily acne-prone skin.

While salicylic acid does not increase sun-sensitivity, we still recommend wearing SPF.

If you are looking for the ingredient called BHA or Butylated Hydroxyanisole, click here.

In its pure form, Benzoic Acid looks like a white crystalline solid. It has slight solubility in water.

The name of Benzoic Acid comes from gum benzoin, which used to be the sole source of deriving this ingredient. Benzoic Acid is the most simple aromatic carboxylic acid.

Benzoic Acid is naturally occuring in strawberries, mustard, cinnamon, and cloves. It has a slight scent but is not considered to be a fragrance.

Despite being antibacterial, coconut oil may not be great for acne-prone skin. It is comedogenic and may clog pores. This ingredient may not be safe for malassezia or fungal acne.

Note: Coconut Oil should not replace your sunscreen for UV protection. Studies show it only blocks about 20% of UV.

This oil is non-volatile and has a light scent.

The term 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term. For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance.

In many countries, coumarin is banned as a food additive. However, it can be found in soaps, tobacco products, and some alcohol drinks.

Plants use coumarins as a chemical defense. Some plants that have coumarins include lavender, tonka beans, and yellow clovers.

Disodium EDTA is a salt of edetic acid and is found to be safe in cosmetic ingredients.

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.