Protocol Enzyme-Active Retinol Serum Versus PCA Skin Rejuvenating Serum

Protocol Enzyme-Active Retinol Serum Versus PCA Skin Rejuvenating Serum

This anti-aging serum is formulated around Retinol and Niacinamide to soften the look of wrinkles and refine skin texture.

This anti-aging serum is formulated around Gluconolactone and Bisabolol to soften the look of wrinkles and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Aloe Barbadensis Leaf Juice

Water

Niacinamide

Cyclodextrin

Caprylic/Capric Triglyceride

Gluconolactone

Carnitine

Glycerin

Polysorbate 20

Enzymes

Retinol

Retinal

Phenylethyl Resorcinol

Bisabolol

Tocopheryl Acetate

Lonicera Japonica Flower Extract

Lonicera Caprifolium Flower Extract

Sodium Lactate

Lecithin

Alcohol

Pentylene Glycol

Maltodextrin

Xanthan Gum

Sodium Benzoate

Aloe Barbadensis Leaf Juice, Water, Niacinamide, Cyclodextrin, Caprylic/Capric Triglyceride, Gluconolactone, Carnitine, Glycerin, Polysorbate 20, Enzymes, Retinol, Retinal, Phenylethyl Resorcinol, Bisabolol, Tocopheryl Acetate, Lonicera Japonica Flower Extract, Lonicera Caprifolium Flower Extract, Sodium Lactate, Lecithin, Alcohol, Pentylene Glycol, Maltodextrin, Xanthan Gum, Sodium Benzoate

Alcohol Denat.

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Aminomethyl Propanol

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Isomalt

Sodium PCA

Caprylyl Glycol

1,2-Hexanediol

Mentha Piperita Oil

Tocopherol

Citrus Paradisi Peel Oil

Glutathione

Squalane

Oryza Sativa Bran Oil

Citrus Aurantium Dulcis Peel Oil

Phospholipids

Tropolone

Tocotrienols

Camellia Sinensis Leaf Extract

Epigallocatechin Gallate

Aloe Barbadensis Leaf Juice Powder

Fructose

Glycine

Urea

Inositol

Vitis Vinifera Fruit Cell Extract

Sh-Oligopeptide-1

Water, Alcohol Denat., Glycerin, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Aminomethyl Propanol, Gluconolactone, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Polysorbate 20, Bisabolol, Isomalt, Sodium Benzoate, Sodium Lactate, Sodium PCA, Caprylyl Glycol, 1,2-Hexanediol, Mentha Piperita Oil, Tocopherol, Citrus Paradisi Peel Oil, Glutathione, Squalane, Oryza Sativa Bran Oil, Citrus Aurantium Dulcis Peel Oil, Phospholipids, Tropolone, Tocotrienols, Camellia Sinensis Leaf Extract, Epigallocatechin Gallate, Aloe Barbadensis Leaf Juice Powder, Fructose, Glycine, Niacinamide, Urea, Inositol, Lecithin, Vitis Vinifera Fruit Cell Extract, Sh-Oligopeptide-1

Reviews

Be the first to review

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

Bisabolol is a gentle skin conditioner, antioxidant, and soothing ingredient.

It's primary claim to fame is soothing and research shows topically applied bisabolol can quiet the chemical messengers that cause your skin to become inflamed, helping to sooth any irritation.

A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin.

In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum.

You'll likely see use concentrations quite low, usually 0.1-0.2%.

Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure skin.

Gluconolactone is a PHA. PHAs are a great gentle alternative to traditional AHAs.

When applied, Gluconolactone has the same affect on skin as AHAs such as lactic acid. It helps dissolve the dead skin cells in the top layer of your skin. This improves texture and brightens the skin.

PHAs are more gentle than AHAs due to their larger structure. They do not penetrate as deeply as AHAs and take a longer time to dissolve dead cells. Studies show PHAs do not cause as much irritation.

Gluconolactone has some interesting properties:

In a 2004 study, Gluconolactone was found to prevent UV damage in mouse skin cells and has not been found to increase sun sensitivity. However, we still recommend wearing SPF daily.

This ingredient is is an created by reacting gluconic acid with an alcohol.

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.

Niacinamide is a multitasking form of vitamin B3 that strengthens the skin barrier, reduces pores and dark spots, regulates oil, and improves signs of aging.

And the best part? It's gentle and well-tolerated by most skin types, including sensitive and reactive skin.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

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.

Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

Sodium Lactate is the sodium salt of lactic acid, an AHA. It is a humectant and sometimes used to adjust the pH of a product.

This ingredient is part of our skin's NMF, or natural moisturizing factor. Our NMF is essential for the hydration of our top skin layers and plasticity of skin. NMF also influences our skin's natural acid mantle and pH, which protects our skin from harmful bacteria.

High percentages of Sodium Lactate can have an exfoliating effect.

Fun fact: Sodium Lactate is produced from fermented sugar.

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