Dry Skin

If you have dry skin and have wondered what science has to say about what the best ingredients for dry skin really are, this post is for you. I’m posting this as general information and have no affiliate links here; this is for people like you, F.

Dry Skin Basics

What dry skin is and its symptoms and causes.

For you dry skin sufferers, dry skin is obvious.

• It’s scaly, flaky, tight and greyish.
• It may have fine lines and cracks.
• It may bleed.

You also know that there are some common-sense things that you can do to help your skin:

• Take infrequent shorter baths in cool water
• Avoid rough clothing or anything abrasive
• Avoid cigarette smoke
• Don’t use harsh soap, detergents or solvents. ^[1]

The causes of dry skin are often things you cannot control such as genetics, hormones, medication or arid and very cold or hot weather.

Still, it’s possible to help dry skin by picking the right moisturizer or medication. Medications are best discussed with your doctor, but its moisturizers that we tackle here.

 

Do Moisturizers Really Help the Skin?

Yes, You Dry Skin Skeptic, Moisturizers Really Can Help

You’ve probably tried everything.

And you’ve probably given up on moisturizers because you can’t seem to find the right one.

But let’s take a look at what dermatologists and science really has to say about moisturizers.

• By explaining moisturizer use to patients, dermatologist nurses increased moisturizer use by 800% and reduced eczema severity by 89%. ^[2]
• Long-term moisturizer use can actually improve skin barrier function by regularizing keratinocyte differentiation. This means the correct type and amount of different skin cells are produced. Dry skin usually occurs because of irregularities in these factors. ^[3]
• Regular use is important so that there is enough time for the moisturizer to work.
• Preventive use while skin is under control is also important. ^[4]
• Even if skin doesn’t appear dry, this doesn’t necessarily mean that impaired skin barrier function was improved. The amount of water the body continued to lose actually remained the same. ^[5]

 

How Moisturizers Help the Skin

Water Loss (TEWL or Transepdermal Water loss) is marked by a reduction in lipids and natural moisturizing factors in the skin. Epidermal differentiation is crucial in producing the right levels of each.

To understand how the best ingredients for dry skin work, there’s a little bit of skin science that might be useful.

• The outermost layer of the skin and the one most important in skin hydration is called the stratum corneum.
• The stratum corneum is made up of corneocytes or dead keratinocytes that are flattened and filled with keratin.
• The process that produces these corneocytes is called epidermal differentiation which also creates different keratins, proteins, and lipids.
• Corneocytes are held together by lipid bilayers which are made of non-polar lipids such as ceramides, free fatty acids and cholesterol. They help retain water.
• Corneocytes also contain natural moisturizing factors (NMF) or humectants that attract water. Some NMFs are amino acids, lactate, PCA and urea.

NMFs are 15-20% of the stratum corneum by weight.

• Incorrect epidermal differentiation leads to the wrong amount and type of skin cells produced. Lower levels of skin lipids and NMF can increase the water lost from the body (TransEpidermal Water Loss or TEWL).

The Science behind Moisturizer Ingredients and What They Try To Do

As you’ve probably guessed, dry skin can be caused by not being able to regulate the amount of water lost.

Water lost from the body is called Trans Epidermal Water Loss or TEWL.

But why the body can’t regulate water can be tough to figure out.

Like any organ, the skin is a system.

When one thing goes out of whack – the amount of NMF, irregularities in the corneocytes, or repeated assaults on the skin barrier from ingredients – dry skin results.

Moisturizers are made of several ingredients:

Ingredient	Function
Water	Moisturizers are mostly made of water. Water helps humectants work effectively. For instance, undiluted glycerol can actually dry out the skin.
Oil	Oils can help retain water by either creating an occlusive barrier or by increasing levels of naturally occurring oils such as ceramide.
Emulsifiers	Binds water and oil together and stabilizes the mixture.
Preservatives	Protects the mix from spoilage.
Humectants	Humectants draw water from its surroundings and help in hydration.
Silicones	Imparts slip, emollience, and improves skin feel.
Botanical Extracts	May have some benefit but often these are not clearly proven.
Fragrances	Provides scent for customer acceptance.
Chelating Agents	React with metal ions to remove their interference in the formula.
Antioxidants	May have some benefit. Some such as tocopherol are used as preservatives.

 

Ingredient 1 Ceramides

Ceramides are a naturally occurring fat in the skin that has structural and cell signaling functions. Its been shown to decrease TEWL.

• Ceramides are naturally occurring lipids of the skin that are part of the physical structure of the skin.
• Ceramides also function as signal transductors and help regulate epidermal cell differentiation and proliferation.
• Other types of lipids such as petrolatum keep water in by trapping it under a film, but cannot penetrate the skin or help cell differentiation the way ceramides can.
• In an open label, double-blind study, a ceramide lipid mix decreased water loss. ^[6]

Ingredient 2 Glycerol or Glycerin

Glycerol is a naturally occurring chemical found in all triglycerides and in human skin. It is a humectant, meaning it attracts water from its surroundings. It has several well-studied benefits.

• Glycerol is naturally found in the skin and is used for elasticity and barrier functions.
• Its benefits include improved hydration, skin barrier function, irritant protection, accelerated wound healing and is an antimicrobial.

It’s so absorbent that it can absorb its own weight in water in 3 days.

• Glycerol is a better humectant than others not just because it absorbs water but because it penetrates into the skin and creates a reservoir without disrupting the skin.
• Glycerol has no side effects but high concentration can feel sticky and unpleasant on the skin.
• It has a proven record of effectivity for the skin. It can address abnormalities in elasticity and barrier function not always caused by lipid loss. ^[7]

Ingredient 3 Urea

Urea is a colorless compound that is a product of protein metabolism. Its benefits for the skin are proven but it can be irritating.

• Urea was found superior to glycerol in improving skin barrier function. However, urea was found by 20-40% patients to sting. ^[8]
• A 10% Urea cream reduced water loss in ichthyotic patients and 5% was effective for atopic patients.
• Repeated use also reduces sensitivity to sodium lauryl sulfate.

Ingredient 4 AHA

An AHA is an Alpha Hydroxy Acid that can exfoliate but also has hydration effects. Well-studied examples are lactic and glycolic acid.

• AHA can also help relieve dry skin and can help decrease sensitivity to Sodium Lauryl Sulfate.
• Lactic, glycolic and tartaric acids are all examples of AHA.
• AHA has buffering properties and binds water to increase hydration.

Ingredient 5 Panthenol and Dexpanthenol

Panthenol is an alcohol of pantothenic acid (Vitamin B5) which is an emollient and moisturizer. It has been shown to reduce TEWL. Its synthetic derivative is Dexpanthenol.

• Panthenol has been reported to penetrate into skin and convert into panthothenic acid.
• It can help repair the skin barrier, increase hydration and decrease redness.
• 1% and 5% panthenol moisturizers were shown to reduce water loss after 30 days. ^[9]
• Dexpanthenol, a precursor to panthenol, is also effective for skin hydration and in maintaining elasticity.
• It may also activate fibroblast proliferation which is a component of wound healing. ^[10]
• It is not irritating to the skin and may defend against SLS irritation. ^[11]

Ingredient 5 Glycine

Glycine is an amino acid which inhibits histamine release to reduce itching.

• Histamines start a process that tries to remove an allergen from your system.
• By blocking histamine release from mastocytes, Glycine helps stop the itching. ^[12]

Glycine is an antipruritic – or in layman’s terms an anti-itch compound.

Ingredient 6 Botanical extracts and herbs

Herbs have been used in creams for centuries but their use isn’t always supported by science.

• Time of harvest, preparation and its stability have to be taken into consideration.
• Additionally, the species must be taken into consideration. For instance, there are 300 varieties of Aloe Vera and they all have different chemical compositions. Studies on Aloe seldom report which species used.

I’m Aloe Vera pro, though. I’ve known several people who’ve used Aloe Vera for years, and I’ve seen very good effects.

• Plant-derived polyphenols or vitamins are often used as they may have antioxidants. Skin naturally contains ubiquinone, ascorbic acid, uric acid and vitamin E which may be helped by topical application.

Rose oil’s profile and chemical composition can be significantly affected by the time of harvest. ^[13]

But it’s also the combination that matters

If it were that simple though, then most moisturizers would magically solve all your dry skin problems.

Unfortunately, its also the interaction between ingredients that make a moisturizer effective – and this can be pretty complicated.

• Lipid rich cream without any humectant increased sensitivity to SLS but didn’t affect the skin barrier.
• Emulsifiers help stablilize lotions. It is expected that non-ionic emulsifiers would be less irritating to the skin.
• Cholesterol, ceramides and free fatty acids are structural lipids of the skin, and may be more effective than other lipids for treatment. Their ratio in the mix is also important.
• Complete mixes of cholesterol, ceramides and free fatty acids helped skin barrier recovery, while mixes missing one were not effective. ^[14]

• A dexpanthenol lotion with ceramides, cholesterol, glycerol and glycine was tested, with the ceramides and cholesterol as nanocolloids. It improved skin barrier function and decreased skin sensitivity. ^[15]
• An incorrectly formulated moisturizer will actually delay skin barrier function recovery and increase water loss.
• Some may even increase sensitivity to common irritants such as SLS.
• Although several moisturizers might address dryness, they actually might not do anything for the underlying skin barrier issue and might even impair it.

The right kind of moisturizer can help

The right kind of moisturizer can actually help. It can affect not just dryness, but the actual skin barrier function.

• Moisturizers can help dry skin but it’s the right combination of the right ingredients that will actually help.
• Moisturizers can be complex in action to address the differing causes of dry skin. Still, perhaps by realizing what ingredients actually work and how, you will be better informed and make better decisions.

Remember, even if it takes away the dryness, it might actually impair skin barrier function.

• Ingredients such as SLS, fragrance and preservatives are well-known irritants. It’s possible these days to find moisturizers without fragrance and SLS, but preservatives are needed to protect the formula.
• Don’t fall for the hype. Read the label, understand the ingredients and question everything.

References

1. Lazar, AP & Lazar, P. 1991, ‘Dry skin, water and lubrication’ Dermatologic Clinics, vol. 9, no. 1, pp. 45-51. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/2022097. [Accessed on: Jan 3, 2018]
2. Cork MJ, Britton J, Butler L, Young S, Murphy R, Keohane SG. 2003, ‘Comparison of parent knowledge, therapy utilization and severity of atopic eczema before and after explanation and demonstration of topical therapies by a specialist dermatology nurse’, The British Journal of Dermatology, vol. 149, no. 3, pp. 582-9. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/14510993 [Accessed on: Jan 3, 2018]
3. Buraczewska I, Berne B, Lindberg M, Lodén M, Törmä H. 2009, ‘Moisturizers change the mRNA expression of enzymes synthesizing skin barrier lipids’, Archives of Dermatological Research, 301, no. 8, pp. 587-94. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/19466436 [Accessed on: Jan 3, 2018]
4. Holden C, English J, Hoare C, Jordan A, Kownacki S, Turnbull R, Staughton RC. 2002, ‘Advised best practice for the use of emollients in eczema and other dry skin conditions’, The Journal of Dermatological Treatment, 13, no. 3, pp. 103-6. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/12227871 [Accessed on: Jan 3, 2018]
5. Lodén M. 2005, ‘The clinical benefit of moisturizers’, Journal of the European Academy of Dermatology and Venereology, vol. 19, no. 6, pp. 672-88. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/16268870 [Accessed on: Jan 3, 2018]
6. Lodén M. 2003, ‘Role of topical emollients and moisturizers in the treatment of dry skin barrier disorders’, American Journal of Clinical Dermatology, 4, no. 11, pp. 771-88. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/14572299 [Accessed on: Jan 3, 2018]
7. Fluhr JW, Darlenski R, Surber C. 2008, ‘Glycerol and the skin: holistic approach to its origin and functions’, The British Journal of Dermatology, 159, no. 1, pp. 23-34. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/18510666 [Accessed on: Jan 3, 2018]
8. Andersson A-C, Lindberg M & Lodén M. 2009, ‘The effect of two urea-containing creams on dry, eczematous skin in atopic patients. I. Expert, patient and instrumental evaluation’, Journal of Dermatological Treatment, 10, no. 3, pp. 165-9. Pubmed-NCBI Available from: http://www.tandfonline.com/doi/abs/10.3109/09546639909056023 [Accessed on: Jan 3, 2018]
9. Camargo FB Jr, Gaspar LR, Maia Campos PM. 2011, ‘Skin moisturizing effects of panthenol-based formulations’, Journal of Cosmetic Science, vol. 62, no. 4, pp. 361-70. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/21982351 [Accessed on: Jan 3, 2018]
10. Ebner F, Heller A, Rippke F, Tausch I. 2002, ‘Topical use of dexpanthenol in skin disorders’, American Journal of Clinical Dermatology, vol. 3, no. 6, pp. 427-33. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/12113650 [Accessed on: Jan 3, 2018]
11. Biro K, Thaçi D, Ochsendorf FR, Kaufmann R, Boehncke WH. 2003, ‘Efficacy of dexpanthenol in skin protection against irritation: a double-blind, placebo-controlled study’, Contact Dermatitis, vol. 49, no. 2, pp. 80-4. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/14641355 [Accessed on: Jan 3, 2018]
12. Proksch E, Lachapelle JM. 2005, ‘The management of dry skin with topical emollients–recent perspectives’, Journal der Deutschen Dermatologischen Gesellschaft, vol. 3, no. 10, pp. 768-74. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/16194154 [Accessed on: Jan 3, 2018]
13. Younis A, Riaz A, Aslam Khan M, Ali Khan A. 2009, ‘Effect of Time of Growing Season And Time of Day for Flower Harvest on Flower Yield and Essential Oil Quality and Quantity of Four Rosa Cultivars’, Floriculture and Ornamental Biotechnology, Available from: http://www.globalsciencebooks.info/Online/GSBOnline/images/0906/FOB_3(SI1)/FOB_3(SI1)98-103o.pdf [Accessed on: Jan 3, 2018]
14. Man MQ, Feingold KR, Elias PM. 1993, ‘Exogenous lipids influence permeability barrier recovery in acetone-treated murine skin’, Archives of Dermatology, vol. 129, no. 6, pp. 728-38. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/8507075 [Accessed on: Jan 3, 2018]
15. Proksch E, Lachapelle JM. 2005, ‘The management of dry skin with topical emollients–recent perspectives’, Journal der Deutschen Dermatologischen Gesellschaft, vol. 3, no. 10, pp. 768-74. Pubmed-NCBI Available from: https://www.ncbi.nlm.nih.gov/pubmed/16194154 [Accessed on: Jan 3, 2018]