Keys Soulcare Promise Serum Review

Keys Soulcare Promise Serum
5.0
/ 10
Moisturizing
10.0 Humectancy icon Humectancy
0.0 Occlusivity icon Occlusivity
6Anti-wrinkle icon/ 10
Anti-wrinkle
Rich
in Antioxidants
Rich Skin Soothing icon
in Skin Soothers
Review

Does Keys Soulcare Promise Serum Work?

 
According to CreamScan AI's analysis of the ingredient list, here’s what Keys Soulcare Promise Serum has to offer:
 
  • Strong humectant moisturizing. This lightweight, humectant-rich product, ideal for oily skin, has a moisturizing rating of 5.0 out of 10.
  • Significant anti-wrinkle efficacy. With an anti-wrinkle rating of 6.0 out of 10, Keys Soulcare Promise Serum is effective in minimizing wrinkles.
  • Soothing: Keys Soulcare Promise Serum contains a high concentration of soothing ingredients, which may help to reduce irritation and calm the skin.
  • Antioxidant protection.

Key Benefits of Keys Soulcare Promise Serum

 
These are the key benefits you can expect from using Keys Soulcare Promise Serum:
 

Lightweight Purely Humectant Moisturizing, Ideal for Oily Skin

According to CreamScan analysis, Keys Soulcare Promise Serum is quite moisturizing, with a moisturizing rating of 5.0 out of 10.

Is it more humectant or occlusive? It is purely humectant. It has zero occlusivity (we didn't find any occlusive ingredients on the ingredient list) and a maximum humectancy of 10 out of 10, primarily due to the high content of Niacinamide (est. ≈5.0%), Glycerin (est. ≈4.0%) and Propylene Glycol (est. ≈3.0%).

This humectant-rich product, when used alone as a moisturizer, is ideal for oily skin, providing significant hydration in a lightweight, fast-absorbing formula without any occlusive ingredients.

Tip: Certain studies suggest that humectants alone may not effectively moisturize the skin. If you use this product as your only moisturizer, we recommend following it with one that contains at least some occlusive ingredients.

A Humectant Boost for Any Skincare Routine

But it’s not limited to oily skin - such a humectant boost will also positively contribute to the moisturizing efficacy of any skincare routine when used as a step before applying the main moisturizer. This type of formulation is typically used in serums, where a light, fast-absorbing texture is key.

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

Significant Anti-Wrinkle Efficacy

According to CreamScan analysis, Keys Soulcare Promise Serum has a high anti-wrinkle rating of 6.0 out of 10.

It contains one ingredient with proven anti-wrinkle efficacy: Niacinamide (est. ≈5.0%), 
 one of the most effective and well-researched anti-wrinkle ingredients. A clinical study involving 30 participants (Kawada et al.) confirmed that a cream with 4% niacinamide reduced the average depth of wrinkles around the eyes by 9% after 8 weeks of use, compared to a vehicle (the same formulation without niacinamide).
 
Among others, Keys Soulcare Promise Serum also contains 3-O-Ethyl Ascorbic Acid, an ingredient often marketed as effective in reducing wrinkles. However, the studies supporting the anti-wrinkle claims of 3-O-Ethyl Ascorbic Acid provide insufficient evidence of its efficacy according to CreamScan Research Evaluation Standards. Therefore, this ingredient does not contribute to the anti-wrinkle rating.
 

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

Rich in Skin-Protecting Antioxidants

We estimate that Keys Soulcare Promise Serum is rich (> 3%) in antioxidants, specifically Niacinamide (est. ≈5.0%).

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.

Skin Soothing and Calming Potential

Based on the ingredient list analysis, Keys Soulcare Promise Serum is rich (> 5%) in soothing ingredients, particularly Niacinamide (est. ≈5.0%).

When applied to the skin, compounds of soothing ingredients, such as triglycerides, phospholipids, fatty acids, phenolic compounds, and antioxidants, work together to soothe the skin through various mechanisms: reducing inflammation, promoting wound healing, repairing the skin barrier, and providing antimicrobial and antioxidant activities.

Please note that this is not a complete list of benefits. We are in the process of enhancing our AI model to incorporate anti-pigmentation, exfoliation and anti-acne ratings.

Things to Be Aware Of: Keys Soulcare Promise Serum

 
CreamScan AI identified a few things to consider before adding Keys Soulcare Promise Serum to your skincare routine:
 

If It’s Your Only Moisturizer, It Needs to Be Paired with Some Occlusives

While humectants are highly effective at attracting water to the skin, studies (J. N. Kraft, C. W. Lynde) suggest they may not be efficient when used alone.

One major drawback of purely humectant moisturization is that the water attracted by humectants to the upper layers of the skin can evaporate completely into the environment through transepidermal water loss (TEWL). Adding occlusive ingredients helps seal this moisture into the skin and prevent further water loss.

If you’re using Keys Soulcare Promise Serum as your only moisturizer, consider pairing it with one that contains at least some occlusive ingredients, such as oils, butters, or silicones. These work alongside humectants to create a protective barrier, locking in hydration and ensuring longer-lasting moisturization. The amount of occlusive needed depends on your skin type - the drier the skin, the more occlusives it requires.

If this product is used not as a standalone moisturizer but as part of your skincare routine, such as a toner or serum, it should be applied before your main moisturizer (unless it's a sunscreen), which will provide the necessary occlusivity on top of it.

Pros & Cons of Keys Soulcare Promise Serum

 
Here’s an overview of the pros and cons of Keys Soulcare Promise Serum to help you decide if it’s the right choice for your skincare routine:
 

Pros:

  • Humectant-rich moisturizing ideal for oily skin
  • Lightweight texture
  • A humectant moisturizing boost for any skincare routine
  • Delivers signficant anti-wrinkle efficacy
  • Rich in antioxidants that combat oxidative stress associated with accelerated skin aging and defend against environmental damage such as UV radiation and pollution
  • Contains a high concentration of soothing ingredients, which may help reduce irritation and soothe the skin

Cons: 

  • Needs occlusives to seal in humectants if used as a standalone moisturizer

Ingredients

Est. % Ingredient Origin Functions
80
5
4
3
2
1.5
1.3
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
0.3
Est. %
Water
Function:
Origin:
Niacinamide
Function:
Origin:
Glycerin
Function:
Origin:
Propylene Glycol
Function:
Origin:
Erythritol
Function:
Origin:
Zinc PCA
Function:
Origin:
PPG-10 Methyl Glucose Ether
Function:
Origin:
Tremella Fuciformis Sporocarp Extract
Function:
Origin:
3-O-Ethyl Ascorbic Acid
Function:
Origin:
Camellia Sinensis Leaf
Function:
Origin:
Tocopheryl Acetate
Function:
Origin:
PEG-32
Function:
Origin:
PEG-180
Function:
Origin:
Xanthan Gum
Function:
Origin:
Coceth-7
Function:
Origin:
PPG-1-PEG-9 Lauryl Glycol Ether
Function:
Origin:
PEG-40 Hydrogenated Castor Oil
Function:
Origin:
Disodium EDTA
Function:
Origin:
Phenoxyethanol
Function:
Origin:
Ethylhexylglycerin
Function:
Origin:
Caprylyl Glycol
Function:
Origin:

Ratings

All humectants
17.7
5
4
3
2
1.5
1
0.3
0.3
0.3
0.3
Benchmark
10
All occlusives
0.0
None
Benchmark
20
Moisturizing rating
5.0
Ingredient Est. % Benchmark Raiting
Humectancy All humectants 17.7 10
10.0
5
4
3
2
1.5
1
0.3
0.3
0.3
0.3
Occlusivity All occlusives 0.0 20
0.0
None
Moisturizing rating
5.0
Ingredient Est. % Benchmark Humectancy
5
4
3
2
1.5
1
0.3
0.3
0.3
0.3
All humectants 17.7 10
10
All humectants
17.7
5
4
3
2
1.5
1
0.3
0.3
0.3
0.3
Benchmark
10
Ingredient Est. % Benchmark Occlusivity
None
All occlusives 0.0 20
0.0
All occlusives
0.0
None
Benchmark
20
Ingredient
Ingredient anti-wrinkle power
when present at, %
in this formula est. %
Rating
6 /10 4 5 6
n/a
- 0.3 -
Total
6
Niacinamide
6
Ingredient anti-wrinkle power
6 /10
when present at, %
4
in this formula, est. %
5
3-O-Ethyl Ascorbic Acid
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Anti-wrinkle rating
6
Ingredient Est. % Benchmark
Rich in Antioxidants
5
1
0.3
0.3
All antioxidants 6.6 3 Rich in antioxidants
All antioxidants
6.6
Niacinamide
5
Tremella Fuciformis Sporocarp Extract
1
3-O-Ethyl Ascorbic Acid
0.3
Tocopheryl Acetate
0.3
Benchmark
3
Ingredient Est. % Benchmark
Rich in Soothing
5
All soothing 5 5 Rich in soothing
All soothing
5
5
Benchmark
5

Ingredients explained

Water
Est. %80
Function
Origin
WaterThe most used ingredient in skincare. Its concentration defines the product texture: rich creams may have about 50% of water while a light jelly about 90%. Water doesn’t moisturize the skin by itself and is used in skincare as a solvent for other ingredients.
Niacinamide
Est. %5
Function
Origin
Niacinamide

Also known as vitamin B3, this ingredient is a true superstar with confirmed moisturizing, anti-acne, hyperpigmentation, and antioxidant benefits. Two studies confirm its significant anti-wrinkle efficacy.

Glycerin
Est. %4
Function
Origin
Glycerin

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

Propylene Glycol
Est. %3
Function
Origin
Propylene GlycolA 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.
Erythritol
Est. %2
Function
Origin
ErythritolA naturally occurring sweetener that hydrates skin by drawing in water.
Zinc PCA
Est. %1.5
Function
Origin
Zinc PCAA two-part ingredient: Zinc helps to control sebum and bacteria in acne-prone skin, while skin-identical PCA is a moisturizing humectant. Zinc PCA may even boost collagen production and so is researched as a potential anti-wrinkle ingredient.
PPG-10 Methyl Glucose Ether
Est. %1.3
Function
Origin
PPG-10 Methyl Glucose Ether
Tremella Fuciformis Sporocarp Extract
Est. %1
Function
Origin
Tremella Fuciformis Sporocarp ExtractA fungi extract. The mushroom contains various proteins, fiber, and humectant and antioxidant polysaccharides - which help to restore the water and collagen content in the skin.
3-O-Ethyl Ascorbic Acid
Est. %0.3
Function
Origin
3-O-Ethyl Ascorbic AcidA derivative of vitamin C. Its stability in skincare formulations is better than ascorbic acid’s, although clinical studies are yet to indicate whether it has the same collagen-boosting benefits.
Camellia Sinensis Leaf
Est. %0.3
Function
Origin
Camellia Sinensis Leaf
Tocopheryl Acetate
Est. %0.3
Function
Origin
Tocopheryl Acetate

An antioxidant derivative of tocopherol (vitamin E). It helps to protect cells from free radicals and UV damage through the conversion to active vitamin E in the skin. It is more stable than tocopherol.

PEG-32
Est. %0.3
Function
Origin
PEG-32A synthetic water-loving moisturizer that produces water gels.
PEG-180
Est. %0.3
Function
Origin
PEG-180
Xanthan Gum
Est. %0.3
Function
Origin
Xanthan GumA natural multi-functional ingredient that originates from fermented sugars. Xanthan gum acts as a viscosity-building agent to thicken skincare products. It is also an excellent stabilizer and works well to hold other ingredients together.
Coceth-7
Est. %0.3
Function
Origin
Coceth-7
PPG-1-PEG-9 Lauryl Glycol Ether
Est. %0.3
Function
Origin
PPG-1-PEG-9 Lauryl Glycol Ether
PEG-40 Hydrogenated Castor Oil
Est. %0.3
Function
Origin
PEG-40 Hydrogenated Castor OilA castor oil-derived ingredient often used to incorporate small amounts of oil (such as a fragrance) into a water-based product. PEG-4 HCO is a gold-standard solubilizer and can be used in low amounts due to its ability to solubilize things so well.
Disodium EDTA
Est. %0.3
Function
Origin
Disodium EDTAA synthetic chelator that helps to maintain the look and smell of a product by 'locking up' troublesome metal ions.
Phenoxyethanol
Est. %0.3
Function
Origin
PhenoxyethanolThe most frequently used preservative in skincare. It is a clear, oil-like liquid synthetic substance that protects products from harmful bacteria and yeast, whilst still leaving skin microflora unharmed. It is confirmed by research to be harmless.
Ethylhexylglycerin
Est. %0.3
Function
Origin
EthylhexylglycerinA preservative booster derived from glycerin. It is commonly paired with other preservatives to improve their efficacy. Ethylhexylglycerin is also a humectant due to its chemical base of glycerin.
Caprylyl Glycol
Est. %0.3
Function
Origin
Caprylyl GlycolAn emollient that improves product spreadability and offers a silky feel on the skin. It also acts as a preservative booster that improves the efficacy of other preservatives. According to the manufacturer, it is also a humectant moisturizer.