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Skin science article

The INKEY List Niacinamide Oil Control Serum Versus The INKEY List Collagen Peptide Serum

The INKEY List Niacinamide Oil Control Serum Versus The INKEY List Collagen Peptide Serum This oil-control serum is formulated around Niacinamide to balance excess oil and refine the look of pores. This anti-aging serum is formulated around Palmitoyl Tetrapept

The INKEY List Niacinamide Oil Control Serum Versus The INKEY List Collagen Peptide Serum

This oil-control serum is formulated around Niacinamide to balance excess oil and refine the look of pores.

This anti-aging serum is formulated around Palmitoyl Tetrapeptide-7 to soften the look of wrinkles and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Niacinamide

Glycerin

Propanediol

Butylene Glycol

Phenoxyethanol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Hydroxyethylcellulose

Phospholipids

Squalane

Xanthan Gum

Glycine Soja Oil

Allantoin

Sodium Phytate

Polysorbate 60

Panthenol

Glycolipids

Leuconostoc/Radish Root Ferment Filtrate

Sorbitan Isostearate

Glycine Soja Sterols

Citric Acid

Hyaluronic Acid

Disodium Phosphate

Sodium Phosphate

Water, Niacinamide, Glycerin, Propanediol, Butylene Glycol, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Hydroxyethylcellulose, Phospholipids, Squalane, Xanthan Gum, Glycine Soja Oil, Allantoin, Sodium Phytate, Polysorbate 60, Panthenol, Glycolipids, Leuconostoc/Radish Root Ferment Filtrate, Sorbitan Isostearate, Glycine Soja Sterols, Citric Acid, Hyaluronic Acid, Disodium Phosphate, Sodium Phosphate

Carbomer

Sodium Lactate

Palmitoyl Dipeptide-5 Diaminobutyroyl Hydroxythreonine

Palmitoyl Dipeptide-5 Diaminohydroxybutyrate

Polysorbate 20

Palmitoyl Tetrapeptide-7

Palmitoyl Tripeptide-1

Water, Glycerin, Butylene Glycol, Propanediol, Phenoxyethanol, Hydroxyethylcellulose, Sodium Phytate, Citric Acid, Leuconostoc/Radish Root Ferment Filtrate, Carbomer, Hyaluronic Acid, Sodium Lactate, Palmitoyl Dipeptide-5 Diaminobutyroyl Hydroxythreonine, Palmitoyl Dipeptide-5 Diaminohydroxybutyrate, Polysorbate 20, Polysorbate 60, Disodium Phosphate, Sodium Phosphate, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1

Reviews

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.

Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.

However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.

Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.

In skincare formulas, citric acid can:

While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.

Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.

Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.

However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.

Disodium Phosphate is a water-soluble powder used as a pH adjuster and mild chelating agent. It basically holds a specific pH and binds stray metal ions so your product stays stable.

This ingredient is usually used at very low levels and concentrations range from 0.000054% - 2.9%. The CIR Expert Panel states this ingredient to be non-irritating at current use levels.

Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.

Topically, glycerin does several things at once:

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.

Hyaluronic acid (HA) is a glycosaminoglycan (basically a long sugar chain) that your skin already makes on its own. In your skin, HA lives in the extracellular matrix and acts as the body's moisture reservoir.

Topically, HA is a humectant that binds water and helps skin look more plump, smooth, and hydrated.

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:

Hydroxyethylcellulose is used to improve the texture of products. It is created from a chemical reaction involving ethylene oxide and alkali-cellulose. Cellulose is a sugar found in plant cell walls and help give plants structure.

This ingredient helps stabilize products by preventing ingredients from separating. It can also help thicken the texture of a product.

This ingredient can also be found in pill medicines to help our bodies digest other ingredients.

Leuconostoc/Radish Root Ferment Filtrate is a natural preservative. It comes from fermenting radish roots with a bacteria called leuconostoc. The trade name for this ingredient is Leucidal.

Leuconostoc comes from lactic acid.

This ingredient has antimicrobial properties and helps prevent the growth of bacteria in a product.

Leuconostoc is used to make the traditional Korean side-dish, kimchi. It is also used to make sourdough bread (both incredibly yummy foods).

Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).

It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.

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.

Polysorbate 60 is used to help stabilize products. It is a surfactant and emulsifier. These properties help keep ingredients together in a product. Surfactants help reduce surface tension between ingredients with different states, such as liquids and solids. Emulsifiers help prevent oils and waters from separating.

Polysorbate 60 is sorbitol-based and created from the ethoxylation of sorbitan. Ethoxylation is a chemical reaction used to add ethylene oxide. Sorbitan is a the dehydrated version of sorbitol, a sugar found in fruits.

In this case, the 60 comes from reacting 60 units of ethylene oxide with sorbitan.

Polysorbates are commonly used in medicine and foods.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.

It’s often used to:

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Sodium Phosphate is is behind-the-scenes formulation helper. Its main job is buffering, or locking in the product's pH.

This helps ensure the formula stays at its intended acidity through manufacturing, shipping, and sitting on your shelf. Many active ingredients like vitamin C or retinoids are pH sensitive so maintaining their happy pH range matters.

It is synthetic and reported use concentrations are very low (up to 0.086% in face powders).

Sodium Phytate is the synthetic salt form of phytic acid. Phytic acid is an antioxidant and can be found in plant seeds.

Sodium Phytate is a chelating agent. Chelating agents help prevent metals from binding to water. This helps stabilize the ingredients and the product.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

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!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

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Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 031,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.
  4. 04It is a:
  5. 05Humectant, drawing moisture into the skin
  6. 06Emollient, helping to soften skin
  7. 07Solvent, dispersing and stabilizing formulas
  8. 08Preservative booster, enhancing the antimicrobial activity of other preservatives
  9. 09Acrylates/C10-30 Alkyl Acrylate Crosspolymer is a synthetic polymer. It is used to thicken, emulsify, and improve the texture of products.
  10. 10As an emulsifier, it helps stabilize oil-in-water emulsions to give products an elegant feel when applied.
  11. 11It 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.
  12. 12A 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.
  13. 13Coco-Caprylate/Caprate is a lightweight ester created from coconut oil fatty acids, caprylic acid, and capric acid.
  14. 14It is an emollient that helps soften skin and reduce transepidermal water loss (TEWL). What sets it apart from heavier emollients is its ultralight, non-greasy feel.
  15. 15Once applied, this ingredient dries down quickly and leaves a dry, silky finish behind. This also helps improve spreadability and texture.
  16. 16This ingredient has an excellent safety-record and is non-irritating.
  17. 17Typical concentrations for cosmetics range from 0.5-62%.
  18. 18Research on Malassezia growth found no growth on fatty acid esters with chain lengths shorter than 12 carbons (it prefers C11-24).
  19. 19Since Coco-Caprylate/Caprate is built on C8 and C10 fatty acids, it is out of the range that Malassezia metabolizes, and therefore safe for fungal acne.
  20. 20Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Source · skinsort.com
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Product index

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Comparison edit

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