Glossary

Dermatologically tested means the final product formula was evaluated in a clinical safety study involving human participants, conducted under the supervision of a dermatologist. The study followed a controlled protocol (such as a repeat insult patch test) to assess skin compatibility and confirm a very low risk of irritation.

Dermatologically tested is not a legally defined term. Companies are not required to perform it to sell their products. Companies may decide to pay to have it conducted, and then they can make the dermatologically tested claim in their marketing materials.

Clinically tested indicates that the product's efficacy – its ability to deliver specific, measurable skin benefits – has been evaluated in a controlled study involving human participants. Unlike dermatological testing, which focuses on safety, clinical testing measures quantifiable performance outcomes such as hydration levels, wrinkle depth, elasticity, or brightness, providing evidence that the product works as claimed.

Simple analogy:

• Dermatologically tested = This product is unlikely to harm your skin
• Clinically tested = This product is proven to improve your skin as claimed

Why the confusion?
Many brands conduct a clinical safety study (which is, technically, a type of clinical test for safety). However, a robust clinically tested claim should involve separate studies measuring specific performance outcomes.
Demand more from brands claiming clinically tested products. Often, these claims are not backed by the actual tests, but unfortunately, specific regulations do not protect consumers equally in all parts of the world.

Here's a quick recap to make things crystal clear:

Our approach to testing dermatologically and clinically

We at Lumessentials paid a third party to conduct a dermatological test on sensitive skin. The test confirmed that our products are safe and gentle for all skin types, including sensitive skin. That is why we're making "dermatologically tested on sensitive skin" claim on our products and website.

On the other hand, we did not conduct clinical trials. Clinical trials that prove a finished formula's efficacy are scientifically valuable, but they are also extremely expensive and resource-intensive. This creates a significant barrier, often reserving such testing for large corporations with vast budgets. As a small, self-funded brand, we don't have the capacity to fund such trials at the moment. Instead, we have chosen to invest our capital differently: directly into superior, ethically sourced ingredients and sustainable packaging, not into costly proprietary clinical trials.

We build on a mountain of existing science. Every key active ingredient in our formulas – such as ceramides, vitamin C (SAP), and natural moisturizing factors – has been selected for its extensive, peer-reviewed clinical history. Independent, published research already confirm their safety and measurable benefits for skin health.

Our formulation philosophy is one of intelligent minimalism. We combine these clinically-validated ingredients at effective concentrations in stable, synergistic formulas. We trust the foundational science and focus our innovation on creating responsible products that are as good for the planet as they are for your skin.

Consumer perception studies are surveys. A group of people use a product for a set period of time, then answer questions about their experience. Did their skin feel softer? Did they notice a difference? Do they like the texture?

Consumer perception studies are conducted as follows:

• Participants receive the product and use it as directed, typically for 2–4 weeks.
• Participants then complete questionnaires rating their experience with statements like "My skin felt more hydrated" or "I noticed reduced redness".
• Results are tabulated as percentages: "82% agreed their skin felt more hydrated".

What the results actually tell you:
These studies measure subjective experience, i.e. how people felt about the product. They're valuable for understanding sensory appeal, user satisfaction, and whether people enjoy using the product enough to keep buying it.

However, these results don't measure physiological changes in the skin. They tell you what people think happened, not what objectively did happen.

Clinical studies use scientific instruments and trained evaluators to measure actual changes in the skin. They're conducted in controlled environments with standardized protocols:

• Participants follow a strict protocol with regular visits to the testing facility.
• Measurements are taken at baseline (before starting) and at regular intervals using calibrated instruments.
• Common measurements include:
  • Corneometer: Measures skin hydration levels
  • Cutometer: Measures skin firmness and elasticity
  • Visia or similar imaging: Tracks changes in pigmentation, texture, and wrinkles
• Many studies are randomized, controlled, and sometimes blinded to eliminate bias.

What the results actually tell you:
These studies provide objective data about what the product actually does to skin physiology. When a study shows "hydration increased by 49%", that's a corneometer reading – it's not someone's opinion.

Here's the thing most brands won't tell you: Of course your skin felt smoother after applying cream. That's what cream does.

Bottomline

• Consumer studies tell you: "People enjoyed using this product and thought it worked".
• Clinical studies tell you: "This product measurably changed skin physiology".

Beware of marketing traps

Any properly formulated moisturizer contains humectants (to attract water) and occlusives (to seal it in). Apply it, and your skin immediately feels softer and smoother. That's not proof of efficacy – it's proof of physics.

When a brand boasts "95% of users felt smoother skin after application", they're essentially saying "95% of users experienced the intended function of a moisturizer". It's like running a perception study on umbrellas and announcing "92% of participants stayed dry in the rain". Duh. That's what it's designed to do.

The marketing version sounds impressive. The honest version asks: What else happened? Did it actually strengthen your barrier over time? Did measurable hydration persist hours later?
If a brand leads with immediate sensory claims and nothing else, ask yourself what they're not telling you.

The European Union has one of the world's strictest cosmetic safety regulations. The EU Cosmetics Regulation (EC) No 1223/2009 is a comprehensive law that governs every aspect of a cosmetic product's lifecycle to ensure consumer safety. Every product sold in the EU must comply with this Regulation. Here are a few key aspects that are enforced through this Regulation:

• Every product must have a Product Information File (PIF) and a Safety Assessment Report, signed by a qualified expert, proving it is safe under normal use.
• It mandates full ingredient disclosure via the INCI system on labels and bans over 1300 potentially harmful substances (the "Annex II" prohibited list).
• Any claim made (e.g., "for sensitive skin") must be backed by verifiable evidence, preventing misleading marketing.
• All products must be manufactured under Good Manufacturing Practices (GMP) and notified to the EU's Cosmetic Products Notification Portal (CPNP) before being placed on the market.
• It fully bans testing finished cosmetic products and cosmetic ingredients on animals within the EU.

The INCI list (International Nomenclature of Cosmetic Ingredients) is the standardized, universal system for naming every ingredient in a cosmetic product. It is your legal, unfiltered ingredient roadmap, designed for clarity and consistency across global markets.

Ingredients on the INCI list are listed in descending order of concentration. The ingredient present at the highest percentage is listed first. Ingredients at 1% or less can be listed in any order after that threshold.

What's in a name?

• Botanical ingredients are listed by their Latin genus and species names (e.g., Helianthus Annuus (Sunflower) Seed Oil) to ensure precise botanical identification worldwide.
• Synthesized/chemical ingredients are listed using standardized English scientific names (e.g., Glycerin, Sodium Hyaluronate).
• Colorants are listed by their CI (Colour Index) numbers (e.g., CI 77491 for Iron Oxides).

Should I read the INCI list?

Absolutely. Reading the INCI list empowers you to know exactly what ingredients you are applying to your skin. The list helps you check if there are any ingredients you'd like to avoid, or see if the product has the potential to be as effective as the marketing says it is. Make it into a habit to read the list before each and every purchase.

INCI list limitations

As useful as the INCI lists are, they do have their limitations. Several points will remain unknown unless the brand specifically mentions them. From the INCI list, you cannot know:

• The source of the ingredients (natural, naturally-derived, synthetic; of animal origin or vegan, etc.)
• The effectiveness of the actives on the list. A high % of an active doesn't mean it's going to be as effective as they claim. The stability of the formula, the delivery system, the pH of the formula all play a crucial role in whether the product is effective.
• The skin feel and scent of the product.
• The exact concentration of the plant extract and their quality. The INCI list doesn't tell you what extraction principle was used and what active compounds are present in the mixture of that plant extract.

The claim natural is largely unregulated at the EU legislative level. Unlike the term organic, which is protected for food (EC 834/2007) and referenced in private cosmetic standards, the term natural for cosmetics has no legal definition under the Regulation EC 1223/2009. This gap is filled by private standards (COSMOS, Natrue) and the technical guidelines of ISO 16128.

A major misconception is that a "natural ingredient equals safe ingredient". This is not true. Many plant extracts are natural but poisonous, hence harmful. Many natural ingredients are common allergens (for example, essential oils or botanical extracts). Natural doesn't equal better, so don't let dishonest marketing trick you into believing so.

There is no official regulation nor harmonized criteria on the definitions of "natural" and "organic" for cosmetics in the EU.

The term "organic" is protected for food (EC 834/2007) in the EU and is referenced in private cosmetic standards. However, the term "natural" for cosmetics has no legal definition under the Regulation EC 1223/2009. This gap is filled by private standards (COSMOS, Natrue) and the technical guidelines of ISO 16128.

Expiration date is the deadline for unopened products. It's the date until which the product is guaranteed to be safe and effective when stored properly, based on stability testing. It applies to products with a lifespan of less than 30 months. You'll see it marked explicitly on the product packaging.

PAO (Period After Opening) is the timer for opened products. It's the number of months (e.g., 12M) a product remains safe and stable after you first open it, indicated by the open jar symbol on the packaging. This is crucial because exposure to air, light, and bacteria can degrade ingredients over time.

Always store products in a cool, dry place away from direct sunlight to help them last as long as intended.

In full compliance with the EU Cosmetics Regulation (EC) No 1223/2009, every Lumessentials product is backed by a mandatory Product Safety Report. This includes comprehensive stability and preservative efficacy testing, and a final safety approval signed by a qualified safety assessor.

Dehydrated skin is a temporary skin condition characterized by a lack of water. Think of it as your skin being thirsty. It can affect any skin type, even oily skin. It normally occurs when the water content of the stratum corneum drops below the 20–30% needed for optimal function.

Dehydrated skin leads to shrinking skin cells, flaking, and cracking. This can even cause oily skin to feel paradoxically dry and oily at the same time. Skin might feel tight after washing, and temporary wrinkles and fine lines from water loss form.

Dry skin is different from dehydrated skin. Dehydrated skin needs water, while dry skin is characterised by a lack of oil, which can leave it cracked or flaky as it struggles to retain water and reinforce the barrier.

Natural moisturising factors (NMFs) build your skin's own hydration system. These are naturally occuring water-soluble compounds that keep your skin plump, flexible, and resilient every single day. The main job of these molecules is to attract water in the very top layer of your skin (stratum corneum). This ensures that your skin stays hydrated from within.

Here are a few examples of NMFs:

• Glycerol (Glycerin)
• Urea
• Sorbitol
• Sodium PCA
• Lactic Acid
• Amino acids (like Glicine or Alanine)
• Hydrolyzed proteins (like hydrolyzed wheat protein, they can mimic or supplement the peptide components of NMFs)

Your NMF levels aren't fixed. They can be depleted by harsh weather, aging, UV exposure, and aggressive skincare (like over-cleansing or high-alcohol toners). When your NMFs are low, your skin's ability to hold onto water plummets. This leads to dehydration, tightness, flakiness, and a weakened barrier – exactly what you want to avoid.

Think of your skin like a plant. Hydration is the water you pour into the soil. Moisturisation is the pot that holds the water in.

• Hydration is about adding water. It's the process of infusing the skin cells with moisture, which makes them plump, dewy, and resilient. This is the job of humectants.
• Moisturisation is about preventing water loss. It's the process of creating a protective seal on the skin's surface to lock that hydration in and reinforce the skin's natural barrier. This is the job of emollients and occlusives.

Your skin needs both. A humectant without a moisturizer is like watering a plant in a sieve – the moisture quickly drains away. A moisturizer without a humectant is like an empty pot – there's nothing to seal in. Moreover, every skin type needs hydration and moisturisation, including oily and acne-prone skin.

Dry skin is different from dehydrated skin. Dry skin needs oil, while dehydrated skin needs water. Read more on dehydrated vs. dry skin in the dedicated tab.

Sources

1. J. W. Fluhr, J. W., et al. (2008). Glycerol and the skin: holistic approach to its origin and functions
2. Lodén, M. (2012). Effect of Moisturizers on Epidermal Barrier Function
3. Rawlings, A. V., & Harding, C. R. (2004). Moisturization and skin barrier function
4. Draelos, Z. D. (2018). The Science behind Skin Care: Moisturizers
5. American Academy of Dermatology (AAD) – Moisturizer: Why you may need it if you have acne

pH is a measure on a scale of 0-14 of how acidic or alkaline something is. A product with a pH of 7.0 is neutral, a pH of less than 7.0 is acidic, and a pH greater than 7.0 is alkaline. pH is only measurable where water is present, as it indicates the concentration of hydrogen ions.

Our skin has a specific slightly acidic pH value. The acid mantle is a thin, protective film that sits on the surface of your skin. It is formed from a combination of sweat and skin sebum, and its pH is typically between 4.5 and 5.5. The pH of our skin varies from one body part to another and from one person to another. It even changes during the aging process. This acidic nature plays a vital role in maintaining healthy skin.

It is common practice to measure and pay attention to the pH of cosmetic products that contain water, such as creams and lotions. You do not need to measure the pH of anhydrous products (products that do not contain water) as a pH, by its definition, is only measured in water.

The pH of a skincare product governs the stability and efficacy of active ingredients. For example, effective exfoliating acids (like glycolic or salicylic acid) and certain forms of Vitamin C (L-ascorbic acid) require a very low pH (between 2.0 and 4.0) to remain active and penetrate the skin. This creates a critical balance: while a low pH makes these actives effective, it can also temporarily disrupt the skin's natural pH and compromise the barrier if misused, leading to irritation, burning, or over-exfoliation.

Therefore, a product's pH isn't just a technical detail – it's a key indicator of both its power and its potential to work with your skin's biology or against it. Intelligent formulation ensures potent actives deliver results without sacrificing long-term barrier health.

Next time you'd like to get one of those fancy serums with a fancy active, ask yourself: what's the pH of the product? What's the ideal pH range for the active to be effective?

Sources

1. Lambers, H., Piessens, S., Bloem, A., Pronk, H., & Finkel, P. (2006). Natural skin surface pH is on average below 5, which is beneficial for its resident flora
2. Schmid-Wendtner, M. H., & Korting, H. C. (2006). The pH of the skin surface and its impact on the barrier function
3. Draelos, Z. D. (2018), Journal of Cosmetic Dermatology, The Science behind Skin Care: Cleansers and Moisturizers

Your skin barrier, also known as the moisture barrier or lipid barrier, refers to the stratum corneum layer of the skin and is the skin's outermost layer. It consists of dead skin cells (corneocytes) and lipids. This barrier provides an important, protective function for our skin. It's mere 0.02 mm thick, yet it is your body's first and most critical line of defense against the world.

This remarkable barrier is structured like a well-built wall. The bricks are hardened skin cells called corneocytes. The mortar is a lipid-rich, oily matrix composed of ceramides, cholesterol, and fatty acids. This structure is continually renewed from below; new cells form, rise to the surface, and eventually shed in a process that takes about 28 days.

A healthy barrier is resilient, supple, and impenetrable to irritants. To maintain this state, it requires:

1. The right lipids: A precise balance of ceramides, cholesterol, and free fatty acids in the mortar is non-negotiable. Disruption of this ratio (often from harsh cleansers or over-exfoliation) weakens the entire structure.
2. Adequate hydration: The barrier needs water to function. Hydration helps maintain its plasticity and flexibility. This is where humectants (like Glycerin) are crucial – they draw and hold water within the barrier itself.
3. A stable pH: Your skin's surface is naturally slightly acidic, with a pH of around 4.5-5.5. This acid mantle inhibits the growth of harmful bacteria and supports the enzymes that help skin cells mature and shed properly.
4. Protection and repair: Daily exposure to UV rays, pollution, and physical abrasion can degrade the barrier. Antioxidants (like Vitamin C) help neutralize this damage, while ingredients like Panthenol and Niacinamide actively support its repair mechanisms.

When the barrier is compromised – manifesting as redness, tightness, flakiness, or heightened sensitivity – the priority is not to treat symptoms with actives, but to restore the foundation. This means using gentle, pH-balanced cleansers and formulas rich in barrier-supporting lipids and hydrators.

Sources

1. Elias, P. M. (2005). Stratum corneum defensive functions: An integrated view
2. Van Smeden, J., & Bouwstra, J. A. (2016). Stratum Corneum Lipids: Their Role for the Skin Barrier Function in Healthy Subjects and Atopic Dermatitis Patients
3. Lambers, H., et al. (2006). Natural skin surface pH is on average below 5, which is beneficial for its resident flora
4. Rawlings, A. V., & Harding, C. R. (2004). Moisturization and skin barrier function

Emollients soften, smooth, and condition the skin's surface by filling in the gaps between skin cells. Emollients improve the skin's texture and flexibility, creating a smooth, supple feel and helping to reinforce the skin's natural barrier.

Many emollients, especially oils and butters, also act as occlusives. This is because their chemical structure allows them to form a protective, hydrophobic (water-repelling) film on the skin's surface. This dual action softens the skin and helps prevent transepidermal water loss (TEWL), making them key for both immediate comfort and long-term hydration.

Find examples of emollients in our Ingredients dictionary.

Humectants are a class of ingredients that act like magnets for water. Their primary function is to attract and bind moisture from the air (hygroscopic effect) and from the deeper layers of your skin, drawing it to the skin's surface and into the outermost layer, the stratum corneum.

This process directly increases the water content of your skin, leading to immediate and tangible benefits:

• Instant plumping: Hydrated skin cells swell slightly, reducing the appearance of fine lines and creating a smoother, fuller look.
• Improved elasticity: Proper hydration makes skin more supple and resilient.
• Enhanced barrier function: A well-hydrated stratum corneum is better able to perform its protective role and maintain overall skin health.

Find examples of humectants in our Ingredients dictionary.

Humectants provide the essential "water" to the skin. For lasting hydration, however, they work best when followed by emollients (to smooth) and occlusives (to seal the moisture in). This creates a complete hydrating system.

Hyaluronic Acid (HA) is the free acid form. In its pure state, it is a large polymer chain that is difficult to dissolve in water and is unstable in solution. It is rarely used "as-is" in cosmetic formulas.

Sodium Hyaluronate (SH) is the sodium salt of hyaluronic acid. This is the stabilized, commercially usable form. The addition of sodium makes it highly water-soluble, stable, and able to penetrate the skin more effectively.

Think of it like this: Hyaluronic Acid is the raw material, and Sodium Hyaluronate is the refined, stable, and functional ingredient you find in skincare products.

The terms HA and SH are used synonymously in marketing because SH is HA, just in its most usable state.

Occlusives form a protective, hydrophobic (water-repelling) layer on the skin's surface. This physical barrier primarily functions to slow down transepidermal water loss (TEWL), helping to seal in hydration and support the skin's natural moisture barrier. Common occlusives include waxes, certain oils, and silicones.

Most occlusives are also classified as emollients. This is because the same oils, waxes, and lipids that create a protective barrier also possess the ability to fill in microscopic cracks between skin cells. Therefore, a single ingredient often performs the dual function of sealing in moisture (occlusion) while simultaneously smoothing and softening the skin's texture (emollience).

Find examples of occlusives in our Ingredients dictionary.