Eighth Day The Regenerative Serum Versus SkinMedica TNS® Advanced+ Serum

Eighth Day The Regenerative Serum Versus SkinMedica TNS® Advanced+ Serum

This anti-aging serum is formulated around Tripeptide-1 and Acetyl Heptapeptide-4 to soften the look of wrinkles and strengthen the skin barrier.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Pentylene Glycol

Sodium Cocoyl/Stearoyl (Alanine/Arginine/Asparagine/Aspartic Acid/Glutamic Acid/Glutamine/Glycine/Histidine/Isoleucine/Leucine/Lysine/Phenylalanine/Proline/Serine/Threonine/Tyrosine/Valine)

Glycerin

Hedychium Coronarium Root Extract

Tripeptide-1

Polygonum Aviculare Extract

Honey

Nonapeptide-1

Acetyl Heptapeptide-4

Phytosphingosine

Sea Whip Extract

Niacinamide

Hydrolyzed Hyaluronic Acid

Aminobutyric Acid

Adenosine

Thioctic Acid

Glycolic Acid

Bacillus

Polysorbate 20

Allantoin

Caprylyl Glycol

Lecithin

Butylene Glycol

1,2-Hexanediol

Dextran

Phenoxyethanol

Ethylhexylglycerin

Xanthan Gum

Water, Pentylene Glycol, Sodium Cocoyl/Stearoyl (Alanine/Arginine/Asparagine/Aspartic Acid/Glutamic Acid/Glutamine/Glycine/Histidine/Isoleucine/Leucine/Lysine/Phenylalanine/Proline/Serine/Threonine/Tyrosine/Valine), Glycerin, Hedychium Coronarium Root Extract, Tripeptide-1, Polygonum Aviculare Extract, Honey, Nonapeptide-1, Acetyl Heptapeptide-4, Phytosphingosine, Sea Whip Extract, Niacinamide, Hydrolyzed Hyaluronic Acid, Aminobutyric Acid, Adenosine, Thioctic Acid, Glycolic Acid, Bacillus, Polysorbate 20, Allantoin, Caprylyl Glycol, Lecithin, Butylene Glycol, 1,2-Hexanediol, Dextran, Phenoxyethanol, Ethylhexylglycerin, Xanthan Gum

Human Neonatal Fibroblast Conditioned Media

Glycereth-7 Triacetate

Shea Butter Ethyl Esters

Ethoxydiglycol

Lactococcus Ferment Lysate

Whey Protein

Chlorella Vulgaris Extract

Saccharide Isomerate

Dimer Tripeptide-43

Vitis Vinifera Flower Cell Extract

Pyrus Malus Fruit Extract

Hydroxyacetophenone

Tocopheryl Acetate

Propanediol

Polyacrylate Crosspolymer-6

Polyacrylate-13

Polyisobutene

Sclerotium Gum

PEG-12 Dimethicone

Pullulan

Sodium Citrate

Aminomethyl Propanol

Disodium EDTA

Water, Pentylene Glycol, Human Neonatal Fibroblast Conditioned Media, Glycereth-7 Triacetate, Shea Butter Ethyl Esters, Glycerin, Ethoxydiglycol, Lactococcus Ferment Lysate, Whey Protein, Chlorella Vulgaris Extract, Saccharide Isomerate, Dimer Tripeptide-43, Vitis Vinifera Flower Cell Extract, Pyrus Malus Fruit Extract, Hydroxyacetophenone, Tocopheryl Acetate, Propanediol, Xanthan Gum, Polyacrylate Crosspolymer-6, Polyacrylate-13, Polyisobutene, Sclerotium Gum, PEG-12 Dimethicone, Lecithin, Pullulan, Butylene Glycol, Sodium Citrate, Polysorbate 20, Aminomethyl Propanol, Disodium EDTA, Phenoxyethanol, Ethylhexylglycerin

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.

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.

Lecithin is a term for a group of substances found in the cell membranes of plants, animals, and humans. They are made up of phospholipids.

Thanks to its amphiphilic structure (water-loving head and oil-loving tail), it is a true multitasker:

It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.

Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:

Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.

On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.

Typical use levels in a formula run about 1-5%.

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 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.

It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

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.

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