Je l’aime iP Thalasso Repair Rich Moist Hair Mask Versus Shiseido Fino Premium Touch Hair Mask

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

An in-vitro study from 2024 found glutamic acid to play a role in inhibiting inflammation and thus a potential skin-soothing ingredient.

Other studies show it to be have potential wound healing, skin barrier repair, and hair growth properties.

Glutamic acid has poor solubility in water and other solvents.

Other types of astringent alcohols include:

According to the National Rosacea Society based in the US, you should be mindful of products with these alcohols in the top half of ingredients.

Any type of sanitizing product will have high amounts of alcohol to help kill bacteria and viruses.

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 is why it works so well topically; PCA is a humectant that holds water in the stratum corneum and studies link higher skin PCA levels to better hydration + lower water loss. Interestingly, people show more PCA in summer and in normal vs dry skin.

Most of the benefits of this ingredient are related to hydration, softness, and barrier support.

A long-running review found that formulas with at least 2% PCA or its salts improved dry skin over both the short and long term. And the zinc salt is also used for its mild antimicrobial and astringent properties.

The salt forms are more common in cosmetics (like sodium PCA).

This ingredient is compatible with basically everything and pairs well with other humectants like glycerin or hyaluronic acid.

Usage-wise, it's typically used at low percentages (~0.2-2%).

The Cosmetic Ingredient Review Expert Panel has concluded PCA and its salts are safe as used and is non-irritating on skin even at high concentrations.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

This is due to how structurally similar it is to what your skin already produces.

Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.

Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.

No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).

Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.

This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.

Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.

Read more about squalene with an "e".

Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.

The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.

Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.

A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.

The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

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!