Kiehl's Powerful-Strength Vitamin C Serum

Kiehl's Powerful-Strength Vitamin C Serum
10.0
/ 10
Moisturizing
10.0 Humectancy icon Humectancy
10.0 Occlusivity icon Occlusivity
2.5Anti-wrinkle icon/ 10
Anti-wrinkle
Rich
in Antioxidants
0
SPF icon
SPF
$$$$

Review

Results you may expect from using Kiehl's Powerful-Strength Vitamin C Serum:

Based on the ingredient analysis by CreamScan, these are the key benefits you can expect from using Kiehl's Powerful-Strength Vitamin C Serum:

  • Intense moisturizing. It has a moisturizing rating of 10.0 out of 10.
  • Some anti-wrinkle efficacy: Kiehl's Powerful-Strength Vitamin C Serum has an anti-wrinkle rating of 2.5 out of 10 so you may expect some, although limited, effect on wrinkles.
  • Antioxidant protection.

How moisturizing is it?

Maximum hydration: Kiehl's Powerful-Strength Vitamin C Serum has the highest possible moisturizing rating of 10.0 out of 10.

Is it more humectant or occlusive? This is one of the most moisturizing products on the market, with a maximum humectancy of 10 out of 10, primarily due to the substantial concentration of Propylene Glycol (est. ≈40.0%) and Glycerin (est. ≈11.0%), and a maximum occlusivity of 10 out of 10, solely because of the significant content of Dimethicone (est. ≈22.0%).

Please refer to the Ratings section below for details of the moisturizing rating calculation.

Anti-wrinkle efficacy

According to CreamScan analysis, Kiehl's Powerful-Strength Vitamin C Serum has a slight anti-wrinkle rating of 2.5 out of 10. It contains one ingredient with proven anti-wrinkle efficacy: Ascorbic Acid (est. ≈10.5%), 
or Vitamin C, a popular anti-wrinkle ingredient, yet with average efficacy confirmed by only one study.
 
Among others, Kiehl's Powerful-Strength Vitamin C Serum also contains contains Ascorbyl Glucoside and Adenosine, two ingredients marketed as effective in reducing wrinkles. However, the studies supporting the anti-wrinkle claims of these ingredients provide insufficient evidence of efficacy according to CreamScan Research Evaluation Standards. Therefore, these ingredients do not contribute to the anti-wrinkle rating.

Please refer to the Ratings section below for details of the anti-wrinkle rating calculation.

Antioxidant benefits

We estimate that Kiehl's Powerful-Strength Vitamin C Serum is rich (> 3%) in antioxidants, specifically Ascorbic Acid (est. ≈10.5%) and Ascorbyl Glucoside (est. ≈2.0%).

A key benefit of antioxidants is their ability to reduce oxidative stress caused by free radicals and therefore prevent accelerated skin aging. Studies also show that antioxidants can protect against environmental damage such as UV radiation and pollution, and help reduce inflammation and skin redness.

Ingredients

Est. % Ingredient Origin Functions
40
22
11
10.5
4
3
2.1
2
1
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
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Ratings

All humectants
51.3
40
11
0.3
Benchmark
10
All occlusives
22.0
22.0
Benchmark
20
Moisturizing rating
10.0
Ingredient Est. % Benchmark Raiting
Humectancy All humectants 51.3 10
10.0
40
11
0.3
Occlusivity All occlusives 22.0 20
10.0
22.0
Moisturizing rating
10.0
Ingredient Est. % Benchmark Occlusivity
22
All occlusives 22.0 20
10.0
All occlusives
22.0
22.0
Benchmark
20
Ingredient Est. % Benchmark Humectancy
40
11
0.3
All humectants 51.3 10
10
All humectants
51.3
40
11
0.3
Benchmark
10
Ingredient
Ingredient anti-wrinkle power
when present at, %
in this formula est. %
Rating
2.5 /10 5 10.5 2.5
n/a
- 2 -
n/a
- 0.3 -
Total
2.5
Ascorbic Acid
2.5
Ingredient anti-wrinkle power
2.5 /10
when present at, %
5
in this formula, est. %
10.5
Ascorbyl Glucoside
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
2
Adenosine
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Anti-wrinkle rating
2.5
Ingredient Est. % Benchmark
Rich in Antioxidants
10.5
2
0.3
0.3
All antioxidants 13.1 3 Rich in antioxidants
All antioxidants
13.1
Ascorbic Acid
10.5
Ascorbyl Glucoside
2
Hydrolyzed Hyaluronic Acid
0.3
Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate
0.3
Benchmark
3
Ingredient Est. % Benchmark Rating
None
All soothing 0 5 No
All soothing
0
None
Benchmark
5

Ingredients explained

Propylene Glycol
Est. %40
Function
Origin
A clear, thick, odorless liquid of synthetic origin. Its main function is to stabilize cosmetic products exposed to varying temperatures. It is also a moderately strong humectant with similar properties to glycerin.
Dimethicone
Est. %22
Function
Origin
The most common silicone in skincare. It forms a silky, smooth film on the skin’s surface and can help to prevent water loss. It also aids in wound healing and can treat and soften scars. Dimethicone is considered to be very safe for use.
Glycerin
Est. %11
Function
Origin

The most popular moisturizing ingredient in the world. It is a powerful humectant – cheap yet very effective.

Ascorbic Acid
Est. %10.5
Function
Origin

Also known as vitamin C, this multi-benefit ingredient has proven anti-wrinkle, antioxidant, and anti-pigmentation efficacy. It degrades easily when exposed to air and light, so it requires proper packaging to maintain its stability.

Ethylhexyl Palmitate
Est. %4
Function
Origin
A rich emollient without the oily after-feel, making it a popular replacement for mineral oil. It is derived from natural sources such as palm oil and palm kernel oil. Ethylhexyl palmitate is listed as a common comedogenic ingredient by acne.org.
Cetyl PEG/PPG-10/1 Dimethicone
Est. %3
Function
Origin
A silicone-based powerful emulsifier that helps to create lightweight and pleasant feeling lotions and creams.
Dimethicone Crosspolymer
Est. %2.1
Function
Origin
A group of ingredients that are typically added to skincare products to adjust the formula. Dimethicone Crosspolymers stabilize a formula, regulate its thickness and consistency and give the product a velvety feel.
Ascorbyl Glucoside
Est. %2
Function
Origin
A derivative of vitamin C. It is more stable and less irritating than ascorbic acid. There are unfortunately no clinical studies on ascorbyl glucoside’s anti-pigment or anti-acne efficacy alone.
Cyclohexasiloxane
Est. %1
Function
Origin
A clear silicone fluid with very low viscosity that is commonly used as a solvent and emollient. It has excellent spreadability, rubs in quickly, and leaves a silky smooth after-feel on the skin.
Hydroxyethylpiperazine Ethane Sulfonic Acid
Est. %0.3
Function
Origin
A pH buffer that secures the pH around 7.5.
Lauroyl Lysine
Est. %0.3
Function
Origin
A synthetic insoluble powder that improves the texture of a product, leaving the skin silky smooth and absorbing oils and sweat.
Acrylonitrile/Methyl Methacrylate/Vinylidene Chloride Copolymer
Est. %0.3
Function
Origin
Description is coming soon
Polysilicone-11
Est. %0.3
Function
Origin
A synthetic rubber-like substance of the silicone family that has no color or distinct scent. These are large molecules that cannot penetrate the skin but instead create a thin silky film on the skin's surface.
Adenosine
Est. %0.3
Function
Origin

A key molecule responsible for energy transportation, signaling, and enzyme activity. Adenosine is a popular anti-wrinkle ingredient, however, the key study about its anti-wrinkle efficacy (1) does not meet CreamScan Research Evaluation Standards as it is not double-blind.

Hydrolyzed Hyaluronic Acid
Est. %0.3
Function
Origin
A smaller-molecule version of the regular hyaluronic acid. It is a powerful humectant that absorbs into the skin and offers moisturizing, smoothing, and anti-wrinkle effects. It is also slightly anti-inflammatory and displays subtle antioxidant properties.
Limonene
Est. %0.3
Function
Origin
One of the most used fragrances in skincare products. It is produced from the peels of citrus fruits and has a fresh, pleasant, citrusy smell. People who are sensitive to citrus should try to avoid it, or at least do a patch test before using it.
Isobutane
Est. %0.3
Function
Origin
A compressed gas used in aerosol cans to help expel and foam skin care products.
Citrus Aurantium Dulcis (Orange) Peel Oil
Est. %0.3
Function
Origin
An essential oil derived from the peels of the sweet orange. It is commonly used as a fragrance because of its pleasant, citrusy scent. The main constituent of the essential oil is limonene (up to 96%).
Citrus Limon (Lemon) Peel Oil
Est. %0.3
Function
Origin
A fragrant essential oil extracted from the rind or peel of a lemon. It is mainly comprised of limonene (up to 70%) and has a fresh, citrusy scent. Lemon peel oil may cause a sun-induced skin rash in people with a sensitivity towards citrus fruits.
Citral
Est. %0.3
Function
Origin
A fragrant compound found in many essential oils (especially lemon myrtle and lemongrass essential oil). It has a sweet, lemon-like scent. People with sensitive skin should try to avoid products with citral, or at least do a patch test before using.
Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate
Est. %0.3
Function
Origin
An antioxidant that protects vulnerable ingredients from the damage caused by ultraviolet radiation, which can also lead to the generation of damaging free radical species.