Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

UK Lash Eyelash Serum Versus UK Lash Complex Peptide Eyelash Serum

UK Lash Eyelash Serum Versus UK Lash Complex Peptide Eyelash Serum What's inside Key Ingredients Benefits Concerns Ingredients Side-by-side Water Glycerin Butylene Glycol Propanediol 1,2-Hexanediol Biotinoyl Tripeptide-1 Camellia Sinensis Leaf Extract Caprylyl

UK Lash Eyelash Serum Versus UK Lash Complex Peptide Eyelash Serum

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Butylene Glycol

Propanediol

1,2-Hexanediol

Biotinoyl Tripeptide-1

Camellia Sinensis Leaf Extract

Caprylyl Glycol

Centella Asiatica Extract

Chamomilla Recutita Flower Extract

Ethylhexylglycerin

Glycyrrhiza Glabra Root Extract

Isopropyl Cloprostenate

Myristoyl Pentapeptide-17

Panthenol

Polygonum Cuspidatum Root Extract

Rosmarinus Officinalis Leaf Extract

Scutellaria Baicalensis Root Extract

Tocopherol

Xanthan Gum

Benzoic Acid

Phenoxyethanol

Sodium Benzoate

Water, Glycerin, Butylene Glycol, Propanediol, 1,2-Hexanediol, Biotinoyl Tripeptide-1, Camellia Sinensis Leaf Extract, Caprylyl Glycol, Centella Asiatica Extract, Chamomilla Recutita Flower Extract, Ethylhexylglycerin, Glycyrrhiza Glabra Root Extract, Isopropyl Cloprostenate, Myristoyl Pentapeptide-17, Panthenol, Polygonum Cuspidatum Root Extract, Rosmarinus Officinalis Leaf Extract, Scutellaria Baicalensis Root Extract, Tocopherol, Xanthan Gum, Benzoic Acid, Phenoxyethanol, Sodium Benzoate

Citrus Limon Fruit Water

Pisum Sativum Peptide

Cocodimonium Hydroxypropyl Hydrolyzed Wheat Protein

Hyaluronic Acid

Curcuma Longa Callus Conditioned Media

Acetyl Hexapeptide-8

Pentylene Glycol

Phytic Acid

Dipeptide Diaminobutyroyl Benzylamide Diacetate

Copper Tripeptide-1

Carbomer

Polysorbate 20

Palmitoyl Oligopeptide

Palmitoyl Tetrapeptide-7

Isochrysis Galbana Extract

Water, Citrus Limon Fruit Water, Propanediol, Pisum Sativum Peptide, Cocodimonium Hydroxypropyl Hydrolyzed Wheat Protein, Butylene Glycol, Hyaluronic Acid, Curcuma Longa Callus Conditioned Media, Caprylyl Glycol, Acetyl Hexapeptide-8, Pentylene Glycol, Phytic Acid, Dipeptide Diaminobutyroyl Benzylamide Diacetate, Copper Tripeptide-1, 1,2-Hexanediol, Glycerin, Carbomer, Polysorbate 20, Palmitoyl Oligopeptide, Palmitoyl Tetrapeptide-7, Centella Asiatica Extract, Polygonum Cuspidatum Root Extract, Scutellaria Baicalensis Root Extract, Camellia Sinensis Leaf Extract, Glycyrrhiza Glabra Root Extract, Chamomilla Recutita Flower Extract, Rosmarinus Officinalis Leaf Extract, Isochrysis Galbana Extract, Phenoxyethanol, Xanthan Gum, Ethylhexylglycerin

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.

It is a:

Humectant, drawing moisture into the skin

Emollient, helping to soften skin

Solvent, dispersing and stabilizing formulas

Preservative booster, enhancing the antimicrobial activity of other preservatives

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.

Camellia Sinensis Leaf Extract (tea extract) is one of the most well-researched plant extracts in skincare with an impressive resume.

Black tea, green tea, and oolong tea are all harvested from the Camellia Sinensis plant.

Studies show green tea extract and its catechins (like epigallocatechin gallate (EGCG)) help your skin cells product energy more efficiently and reducing the number of free-radicals that can damage your skin from the inside.

In lab-grown skin models, this translated to younger, healthier, and stronger skin.

There's also good sun protection data; researchers saw less DNA damage and redness on human skin when green tea was applied before UVB exposure. And the more they applied, the better the protection.

Needless to say, this ingredient shouldn't replace your sunscreen. But it is a great supportive ingredient that you can already find in many sunscreens and antioxidant serums.

A 2009 study found a 2% green tea lotion was effective for mild-to-moderate acne thanks to its anti-inflammatory and mild antimicrobial activity.

The quality of the extract matters a lot here:

Good extracts contain 50-90% catechins while lower quality ones are mostly there for marketing. We recommend reaching out to the brand if you have questions about the quality or source of their ingredients.

Human Repeated Insult Patch Testing showed no irritation or sensitization at use concentrations (0.86% in leave-on products and up to 30% as leaf water).

Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.

Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

Centella Asiatica Extract (Centella) is one of the most researched botanical extracts in skincare with decades of studies backing its effects on inflammation, collagen, and the skin barrier.

That research keeps pointing back to the same four triterpenoid saponins: Asiaticoside, Madecassoside, Asiatic Acid, and Madecassic Acid.

These compounds allow centella to dial back inflammation, encourage the skin to build and hold onto collagen, support the barrier and hydration, and bring solid antioxidant activity to protect against signs of aging.

Centella also carries a nice supporting cast of Vitamin A, vitamin C, several B vitamins, and amino acids. Put it all together and you get an ingredient that soothes, hydrates, and protects, all at once.

Most of centella's magic comes from the four big compounds (Asiaticoside, Madecassoside, Asiatic Acid, and Madecassic Acid). These are the actives doing the heavy lifting in almost every centella study.

Here is the short version of what they do in the skin:

So it is not just soothing for the sake of soothing. Centella calms the skin AND helps it rebuild.

Just FYI, not all centella on an ingredient list is the same. What you are getting actually depends on the extract:

Fun fact on the ratios: the leaves tend to be richest in Madecassoside and Asiaticoside, and lower in the two acids. The exact amounts shift with where the plant is grown and how it is processed. This means purity really does vary brand to brand.

Centella is one of the most easygoing actives out there.

It layers well with basically everything: niacinamide, hyaluronic acid, peptides, and vitamin C, and also pairs nicely with stronger actives like retinoids and exfoliating acids where it can help take the edge off irritation.

On the safety side, centella and its triterpenes are classified as weak sensitizers, meaning allergic reactions are possible but uncommon.

Patch tests at 1% and 5% came back negative in test panels, and creams at typical use levels did not cause allergic reactions across large groups of people.

But as with any new active, a patch test is still a smart move for very reactive skin.

Centella is widely used because it is effective at low percentages. For context, human safety testing found no meaningful irritation from creams containing centella extract at everyday use levels (the tested amounts were well under 1%).

The irritancy threshold in animal testing was also above 30% (so real-world formulas sit far below anything concerning).

In collagen lab studies, higher concentrations drove more collagen synthesis, so serums built around centella tend to feature it more prominently.

Bottom line: you will find centella working nicely anywhere from a fraction of a percent up to hero-ingredient levels depending on whether it is a supporting soother or the main event.

Fun fact: Centella has been used as a medicine and in food for many centuries. As a medicine, it is used to treat burns, scratches, and wounds.

Chamomilla Recutita Flower Extract comes from the Chamomile flower.

Chamomile is rich in antioxidants and has anti-inflammatory properties. Several compounds found in chamomile help with soothing, such as bisbolol.

Antioxidant components in chamomile make it an effective ingredient to help slow the signs of aging. Antioxidants help fight free-radical molecules, or molecules that may damage your skin.

Essential oils from chamomile have been found to improve wound healing due to its antimicrobial properties.

Ancient Greeks and Egyptians used Chamomile to treat skin redness and dryness. Chamomile has also been used to help treat stomach issues.

Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:

The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.

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

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.

Glycyrrhiza Glabra Root Extract is an extract of the roots of Licorice. It has been found to have several benefits such as skin hydrating, conditioning, and soothing.

One component, glabridin, has extra potent antioxidant and soothing properties. It has also been found to block pigmentation from UVB rays in guinea pigs.

Licorice Root also contains a flavonoid. Flavonoids are a natural substance from in plants. Flavonoids also have antioxidant properties.

Another component, glycyrrhizin, has been found to have anti-inflammatory and antimicrobial benefits. This may make licorice root extract effective at treating acne. However, more research is needed to support this.

Liquiritin is one of the flavone compounds found in licorice. It has been found to help lighten skin by preventing tyrosinase from reacting with tyrosine. When the two react, protein is converted to melanin. Melanin is the substance in your body that gives your features pigmentation.

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.

Polygonum Cuspidatum Root Extract comes from the Japanese Knotweed plant native to Japan, Korea, and China.

This plant contains anti-inflammatory and antioxidant properties. It contains high amounts of resveratrol, a potent antioxidant.

The root of the plant has been used in traditional folk medicine throughout Asia.

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.

This is a botanical extract from the rosemary plant (the same one you cook with). In skincare, it mostly works as a skin conditioning agent.

Its activity comes from a handful of polyphenols, carnosic acid, carnosol, and rosmarinic acid. Almost 90% of the antioxidant activity of this ingredient can be attributed to canosol and carnosic acid.

These compounds protect your skin two ways:

1) They fight off free radicals, or the unstable molecules from things like sun and pollution that age and damage skin. 2) They help calm inflammation by switching off the chemical signals that tell skin to get red and irritated.

Lab studies also suggest that rosmarinic acid may help protect collagen and slow sugar-related damage to it.

The Cosmetic Ingredient Review has concluded rosemary-derived ingredients to be safe when formulated to be non-sensitizing.

Rosemary can occasionally cause allergic contact dermatitis (due to carnosol), so be sure to patch test if you have reactive or fragrance-sensitive skin.

Scutellaria Baicalensis Root Extract comes from the Baikal skullcap or Chinese skullcap plant. This plant is native to Northeast Asia and can be found in China, Mongolia, Korea, and Siberia.

In cosmetics, Scutellaria Baicalensis Root Extract provides antioxidant and anti-inflammatory benefits. This is due to the flavonoid composition of Scutellaria Baicalensis Root Extract.

In Chinese traditional folk medicine, Scutellaria Baicalensis Root Extract is used to help treat lung issues and hypertension.

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!

Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.

On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

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

01

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. 03Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
  4. 04Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
  5. 05Though 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.
  6. 06Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  7. 07Topically, glycerin does several things at once:
  8. 08Your 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.
  9. 09Aquaporin-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.
  10. 10This 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.
  11. 11Just know very high concentrations (>40%) can feel tacky in low humidity.
  12. 12Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
  13. 13Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
  14. 14It 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.
  15. 15On 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.
  16. 16Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
  17. 17You'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.
  18. 18Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
  19. 19Safety-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.
  20. 20Adverse 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.
Source · skinsort.com
03

Comparison edit

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