Skincare Ingredients Dictionary

Article Read Duration 10 min read

In the world of skincare, understanding the ingredients list on the back of your products can be a difficult task. Sometimes it feels like you need a skincare dictionary or ingredient glossary as a guide to help you understand the benefits of each formula.

We hear you! That’s why our experts have come together to create an ingredient dictionary to help you choose the right product for your skin type and concerns.

Welcome to the La Roche-Posay skincare ingredient glossary – a comprehensive skincare dictionary and home of everything you need to know about our ingredients.

Aqua Posae

Aqua Posae Filliformis is a postbiotic that grows naturally in our La Roche Posay Thermal Spring Water.

Benefit
Helps increase skin hydration and strengthen the skin’s natural barrier.

How it works
Helps durably rebalance the skin’s microbiome – skin’s invisible living ecosystem of good bacteria.

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Citric Acid

This powerful acid is found naturally in citrus fruits like grapefruits and oranges.

Benefit
Brightens the complexion, exfoliates the skin and helps unclog pores.

How it works
As part of the alpha hydroxy acid (AHA) family, this acid exfoliates by helping dissolve the bonds between dead skin cells. Citric acid also promotes skin cell turnover. Exfoliating acids can cause increased sun sensitivity, so always wear SPF when using this ingredient. 

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Dimethicone

Dimethicone is an emollient ingredient classified as a synthetic polymer of silicone. 

Benefit
Seals in moisture, protects the skin’s surface, helps control shine.

How it works
Dimethicone creates a silky texture on the skin as it fills in the spaces between dead skin cells on the skin’s surface (stratum corneum). 

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Ferulic acid

This powerful antioxidant is derived from plants such as apples, oranges, wheat and rice. 

Benefit
Helps stave off signs of ageing and minimise the appearance of fine lines and wrinkles.

How it works
As an antioxidant, Ferulic acid can neutralise damaging free radicals before they negatively affect the skin. 

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Glycerin

Glycerin is a humectant substance that can be synthesised or found in plants.

Benefit
This powerful moisturiser helps minimise dry or flaking skin by attracting its own weight in water to the skin’s outer layer for an intense hydration.

How it works
Glycerin can attract its own weight in water to the skin’s outer layer.

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Glycolic Acid

This exfoliating acid can be found in vegetables or synthesised. 

Benefit
Glycolic acid has anti-bacterial properties, helps manage redness and improves overall skin clarity and texture for a more even skin tone. 

How it works
This chemical exfoliant helps remove dead skin cells by dissolving the bonds between them. Exfoliating acids can cause increased sun sensitivity, so always wear SPF when using this ingredient. 

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Hyaluronic Acid

This hydrating ingredient occurs naturally in the body and is known as the go-to anti-ageing and skin-plumping molecule. 

Benefit
Hyaluronic acid can re-plump the skin and minimise the look of fine lines. 

How it works
Hyaluronic Acid can hold 1,000 times its weight in water, making it the ultimate hydrating ingredient.

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Intelligent Polymers

This breakthrough innovation in sun care helps provide even sunscreen coverage. 

Benefit
Intelligent polymers help sunscreen formulas achieve even coverage, a non-greasy finish and high resistance. 

How it works
The polymers lock the oil in the sunscreen formula in between micro-crystals to form a strong network of homogenous, non-migrating protection. 

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L-ascorbic acid

Found in citrus or derived synthetically, l-ascorbic acid is a potent form of vitamin C. 


Benefit
This pure form of vitamin C helps improve skin radiance and texture.

How it works
As an antioxidant, L-ascorbic acid can neutralise damaging free radicals before they negatively affect the skin. This form of vitamin C is especially potent. 

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LHA

This salicylic acid derivative is a chemical exfoliant often used in products for acne-prone skin. 

Benefit
Helps decongest pores and refine the skin’s surface.

How it works
As a chemical exfoliant, LHA helps promote skin cell turnover by dissolving the bonds between dead skin cells. As with all acids, it is recommended to combine the application of LHA products with effective sun protection.

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Madecassoside

This extract of the Centella Asiatica herb acts as comforting agent for sensitive skin. 

Benefit
Aids in epidermal renewal and comforts sensitive skin types.

How it works
This ingredient promotes skin barrier strengthening to help alleviate the signs of a weakened skin barrier. 

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Neurosensine

Neurosensine is a dipeptide (type of peptide) naturally present in the skin.

Benefit
Decreases discomfort by significantly reducing skin sensitivity and reactivity.

How it works
This naturally occurring dipeptide can help block sensations of discomfort within the skin. 

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Niacinamide

This ingredient is a form of vitamin B3 naturally found in certain grains, vegetables and meats.

Benefit
Helps minimise the appearance of discolouration, acne-prone skin and redness.

How it works
Helps support the skin’s natural barrier and intensely comforts the skin.

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Pure Vitamin C

Vitamin C is a potent antioxidant that works to prevent the damaging effects of free radicals such as accelerated skin ageing.

Benefit
Improves skin radiance for glowing skin, while also minimising the appearance of wrinkles and fine lines. Pure Vitamin C can also help improve and even out skin tone.

How it works
Works deep within the skin to neutralise damaging free radicals.

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Retinol

This vitamin A derivative is the gold standard in anti-ageing ingredients. 

Benefit
Targets wrinkles, re-plumps the skin and helps minimise acne-prone skin.

How it works
Retinol works deep within the skin to speed up skin cell turnover, helping avoid clogged pores and also stimulating collagen production. Retinol can be known to increase skin’s sensitivity to UV, and so it is recommended to always pair its use with the daily application of facial sunscreen.

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Salicylic Acid

This beta-hydroxy acid is a key blemish fighting ingredient for acne-prone skin. 

Benefit
Helps facilitate visibly clearer skin by reducing sebum production and unclogging pores.

How it works
This acid can penetrate clogged pores to break down existing sebum plugs and prevent future clogged pores. As with all acids, a daily application of sunscreen is recommended for use.

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Shea Butter

This nut butter is obtained from the African Shea Tree.

Benefit
Intensely moisturises the skin and comforts dry skin. 

How it works
Shea butter has lipids similar to the skin’s own, which gives it the ability to restore the skin’s hydrophilic film. 

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Sphingobioma

This unique probiotic fraction is our new innovation.

Benefit
Comforts the skin and helps minimise sensitivity, preventing redness or relapse.

How it works
As a probiotic, sphingobioma helps promote a healthy balance of good bacteria on the skin, acting on the skin’s microbiome.

Squalane

This plant-derived emollient ingredient is well suited to dry or sensitive skin.

Benefit
Helps boost skin hydration, moisturises and calms the skin. 

How it works
Squalane works well with the skin’s natural lubricants to provide a moisturising effect.

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Thermal Spring Water

Our unique thermal spring water contains a mix of trace elements and minerals.

Benefit
This comforting spring water helps rebalance the skin’s microbiome and soften the skin. 

How it works
The antioxidant and prebiotic qualities of this water help control free radical damage and bad bacteria on the skin.

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Vitamin B3

Vitamin B3 is also known as niacinamide. It’s naturally found in some vegetables, grains and meats.

Benefit
Targets skin discolouration, redness and acne-prone skin.

How it works
Helps support the skin barrier and also has a comforting effect for sensitive skin.

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Vitamin B5

Also known as panthenol, vitamin B5 is a renowned nourishing ingredient.

Benefit
Supports the skin’s natural barrier, nourishes dry skin and comforts sensitive skin.

How it works
Vitamin B5 stimulates the skin’s regeneration process and attracts moisture from the air to aid hydration. 

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