RMS Beauty ReEvolve Radiance Locking Hydrating Primer

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.

Dipropylene glycol is technically an alcohol, but it belongs to the glycol family (often considered part of the ‘good’ alcohols). This means it is hydrating and gentle on skin unlike drying solvent alcohols like denatured alcohol.

As a masking agent, Dipropylene Glycol can be used to cover the smell of other ingredients. However, it does not have a scent.

Studies show Dipropylene Glycol is considered safe to use in skincare.

Some studies suggest betaine may support making skin tone more even.

Fun fact: Betaine naturally exists in the skin and the body. In cosmetic products, it can be either plant-derived (most commonly from sugar beets) or synthetically produced for consistency and stability.

Betaine is also known as trimethylglycine.

Emulsifiers prevent oils and waters from separating.

It can also form a thin protective film on skin. One study found that a formula using this polymer helped slow down how quickly other ingredients (like DEET) were absorbed through skin.

A 2024 study of over 1,300 patients confirmed that sensitization to this ingredient is rare. It is also non-mutagenic and has a clean track record.

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

It plays several roles in a formula:

Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.

Multiple assessments have found it to be non-irritating and non-sensitizing to most people.

However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.

Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.

Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.

Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.

This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.

A 2019 study has also observed Malassezia growth in the presence of this ingredient, confirming it to be not-fungal acne safe.

Tromethamine helps balance the pH level of a product. Normal pH level of skin is slightly acidic (~4.75-5.5). The acidity of our skin is maintained by our glands and skin biome. Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

Oral Tromethanmine is an anti-inflammatory drug but plays the role of masking, adding fragrance, and/or balancing pH in skincare.

1,3-Propanediol, 2-amino-2-(hydroxymethyl)-

Polyisobutene is not absorbed by the skin.

It is considered non-irritating on the skin.

The only catch is that HA isn't a single thing; it actually comes in a wide range of molecular weights (~50 - 2,000+ kDA) and size matters.

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

This is why the best HA serums blend the two sizes together so you get the best of both worlds.

The majority of cosmetic HA is produced by bacterial fermentation, typically using Streptococcus or Bacillus strains. Typical use levels in skincare sit around 0.1-2%.

A clinical study using a 0.2% low-molecular weight HA gel showed improvement in facial seborrheic dermatitis with excellent tolerance.

These are some other common types of Hyaluronic Acid:

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

Emulsifiers help stabilize a product. It does this by preventing certain ingredients from separating. Common ingredients include oils and water, which do not mix naturally. Emulsifiers have properties that help keep ingredients such as these together.

Emollients help soothe and soften the skin. They do this by creating a protective film on your skin. This barrier helps trap moisture and keeps your skin hydrated. Emollients may be effective at treating dry or itchy skin.

Surfactants help gather oils, dirt, and other pollutants from the skin. This helps them to be easily rinsed away.

This ingredient is often coated with metal oxides like titanium dioxide. Trace amounts of heavy metals may be found in mica, but these metals are not harmful in our personal products.

Mica has been used since prehistoric times throughout the world. Ancient Egyptian, Indian, Greek, Roman, Aztec, and Chinese civilizations have used mica.

Typical use levels in formulas range from 2-10%.

The CIR Expert Panel has concluded this ingredient to be safe as a cosmetic ingredient.

Since this ingredient is an ester of oleic acid, it may not be fungal acne safe. Oleic acid is a fatty acid that falls into the C11-24 range that Malassezia can metabolize.

Typical use levels range from 10-20% in cleansers and 15-30% in shower products.

Once on your skin, your skin's glucoside hydrolases breaks it down into glucose and the parent fatty alcohols.

This ingredient is considered fungal acne safe because its fatty alcohol portion sits outside the Malassezia yeast's metabolization range.

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.

When used topically, Citrus Aurantium Bergamia Fruit Oil is a photosensitizer due to the furanocoumarin content. Furanocoumarins absorb UV-A and cause phytophotodermatitis; this can look like redness, blistering, and lasting brown pigmentation on sun-exposed skin.

Due to this, this ingredient is capped at 0.4% in leave-on products applied to sun exposed skin.

Many modern formulas used a "furanocoumarin-free" version that sidesteps the phototoxicity issue, but still contains the fragrance allergens.

Squalene is also naturally present in olive oil and exhibits moisturizing and antioxidant properties.

The polyphenols in olive oil also show anti-aging promise; one clinical study found a measurable improvement in skin appearance after 30 days of topical serum use.

Just be aware that applying olive oil directly to skin can weaken the barrier and cause redness. One study with volunteers found even people without sensitive skin experienced a significant reduction in stratum corneum integrity and induced mild erythema.

It's best to use this ingredient as part of a carefully crafted formula (instead of putting it on skin directly from the bottle).

Because it has a 2-3 on the comedogenic scale, it is a moderate risk for acne-prone skin. However, the overall formulation of a product matters more than a few ingredients with comedogenic ratings.

This ingredient may not be fungal acne safe because of the oleic and palmitic acid content. These fall within the C11-24 fatty acid range that the Malassezia yeast can metabolize to grow.

Overall, olive oil is a well-studied and nourishing skincare ingredient.

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.

Citrus peel is also a rich source of flavonoids. Flavonoids are natural antioxidants and help protect your skin against damage. Flavonoids are a group of compounds naturally found in vegetables and fruits.

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.

Lab studies have shown that eggplant extracts can lower oxidative stress and protect skin cell membranes from damage. A 2025 study found that specific compounds in eggplant (particularly a phenolamide called N-Trans-Feruloylputrescine) may support skin health by neutralizing 2-nonenal, a byproduct linked to aging skin.

Overall, this is a gentle, well-tolerated ingredient that adds a little extra antioxidant support to your routine.

Those with nighshade vegetable allergies (tomatoes, peppers, potatoes) should patch test as eggplant is part of the same family.

When exposed to air, these two compounds become strong allergens. This ingredient exhibits cytotoxicity at low concentrations; amounts of 0.25% have been shown to damage skin cells.

A study from Japan found this ingredient caused lavender sensitivity after widespread exposure.

Lavender essential oil has some antimicrobial, antibacterial, and anti-inflammatory properties. However, the cons of this ingredient may outweight the pros.

More research is needed to confirm lavender essential oil's effects when used in aromatherapy.

Lavandula Angustifolia is known as the English Lavender and famous for creating purple fields in Provence, France.

The scent of Rose Geranium closely resembles traditional roses.

In cosmetics, Magnesium Sulfate is used to thicken a product or help dilute other solids. It is a non-reactive and non-irritating ingredient.

One study shows magnesium deficiency may lead to inflammation of the skin. Applying magnesium topically may help reduce inflammation.

You can find this ingredient in sea water or mineral deposits.

Other major parts of Rose Oil include citronellol and geraniol. Both of these are known EU allergens and cause contact-allergies.

The downsides of this ingredient outweight the positives.

Limonene acts as an antioxidant, meaning it helps neutralize free radicals.

When exposed to air, oxidized limonene may sensitize the skin. Because of this, limonene is often avoided by people with sensitive skin.

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.

This ingredient has a scent that is floral, spicy tropical, and citrus-like.

Ci 77891 is commonly found in sunscreens due to its ability to block UV rays.

Synthetically created Ci 77491 is considered safer than those naturally found. This is because the synthetically created version may contain less impurities. Iron oxides are generally non-toxic and non-allergenic.