Cosmetic Skin Care Ingredients Dictionary

Skin Care Ingredients in Skin Care Products

This is the best resource to learn all about skincare ingredients! It is written by skin care ingredient expert Dr. Leslie Baumann MD. This cosmeceutical dictionary contains information about skincare ingredients from my best selling skin care book and dermatology textbooks and my monthly skin care ingredient review column in Dermatology News called “Cosmeceutical Critique.” I have been writing about skin care ingredients for over 25 years.

The ingredient information in this skin care ingredient dictionary is based on evidence - based research.  If you do not know exactly what that mans- please click this link and learn how to tell if a research study is good.

THe Cosmetic Skin Care Ingredient Dictionary: The most common ingredients in skin care, Listed and categorized. Find the best ingredients for your Baumann Skin Type

An Evolving Skin Care Ingredients Dictionary

This ingredient glossary is constantly being updated to stay as current as possible.

You can find categories of skin care ingredients based on their skin benefits and a list of skin care ingredients by INCI name. 

Click on the ingredient to find more detailed information and to find skin care products that contain that ingredient.  All benefits and risks of the skin care ingredients can be found in the individual skin care ingredient blogs.

You can learn more about clean ingredients and the clean beauty standards here.

What are the best skin care ingredients?

The best ingredients for your skin depend upon which of the 16 Baumann Skin Types you are.

Once you know your skin type, you can use this dictionary to find the best skin care ingredients for your skin type.

How To Learn About Skin Care Ingredients

There are several ways to become an expert on skin care ingredients:

  1. Read my bestselling skin care books
  2. Visit our skin care ingredient library
  3. Click on the categories below 
  4. See the list of skincare ingredients and click for detailed information about each ingredient.
  5. Go to our You Tube channel where I interview cosmetic chemists.

The easiest and best way to learn about skin care products is to divide ingredients into categories based skin benefits.

16 Bauman Skin Types and barriers

The Skin Care Ingredients Checker

Anti-Acne Skin Care Ingredients

Ingredients used to treat acne target the causes of acne. 

These anti-acne ingredients can be divided into groups:

Antiaging Skin Care Ingredients

Many antiaging ingredients target the causes of skin aging like cellular senescence.

Anti-aging ingredients work by:

Most popular antiaging skin care ingredients

The most commonly used antiaging ingredients include ascorbic acid, retinoids, defensins, hyaluronic acid, heparan sulfate, peptides and growth factors.

Click on the ingredient name or category to learn more about antiaging cosmeceutical ingredients in skincare products.

Shop for anti-aging products by your skin type

Categories of Antiaging Skin Care Ingredients


Exosomes are the most exciting and newest cutting edge ingredients to treat wrinkles. Click the link to learn more about the different types of exosomes.  You can also learn more by watching our YouTube video about a new platelet derived exosome product.

Growth Factors

There are many types of growth factor skin care ingredients.  The benefits and side effects depend upon which type of growth factor and if they come from humans or plants. Clink the link to learn more and get a list of growth factors in skin care.


There are many types of antiaging peptides. Peptides are made up of amino acids. Click here for a list and to see which are best.



All retinoids are antiaging.  How strong they are depends upon their strength. They target many different antiaging pathways and have many research studies to show they are the best antiaging ingredients in skin care.


Antioxidants neutralize harmful free radicals. They can be used to prevent aging, calm inflammation, and prevent uneven skin pigmentation. Antioxidants are naturally found in many plants. Examples include Vitamin C, Vitamin E, resveratrol, green tea and silymarin. Click here  to learn more about cosmeceutical antioxidant ingredients in skincare products.

Anti-inflammatory Ingredients

Anti-inflammatory ingredients can deactivate one or more of the many inflammatory pathways that lead to inflammation.  Inflammation is such an important cause of skin aging that is is referred to as inflammageing.

Inflammation always consists of dilated blood vessels and redness and may lead to hives, itching and rashes depending on which inflammatory pathways are turned on.

Click here for list of Anti-inflammatory ingredients

How do anti-inflammatory ingredients work?

Anti-inflammatory Skin Care Ingredients

What are clean ingredients

Clean Ingredients

There are many different standards of clean ingredients. Our dermatologists reviewed ingredients and set our own clean beauty standard. Learn details here.

Ingredients for exfoliating the skin

Exfoliating Ingredients

The skin’s natural exfoliation process is called desquamation. When natural desquamation is not enough, exfoliants can be used to increase exfoliation. There are two types of exfoliants: chemical and mechanical. Chemical exfoliants use a low pH or enzymes to dissolve and loosen proteins attachments between skin cells. Mechanical exfoliants use friction to rub dead skin cells off of the surface of the skin.

Chemical Exfoliants

Chemical exfoliants such as glycolic and lactic acids have a low pH and work by loosening the “glue” attachments between skin cells. This allows dead skin cells to flake off of the skin’s surface in a process called exfoliation.

Mechanical Exfoliants-

Loofas, scrubs, brushes, and microdermabrasion devices use friction to physically remove dead skin cells from the surface of the stratum corneum causing exfoliation.

the best moisturizing ingredients

Moisturizing Ingredients

There are many ways that an ingredient can contribute to moisturizing the skin. The most common mechanisms for hydrating the skin include:

  • Barrier repair ingredients - When the skin barrier becomes damaged, it has trouble holding onto water and keeping allergens and irritants out. Barrier repair moisturizers contain ceramides, fatty acids, cholesterol, or beta-sitosterol to strengthen and repair this barrier. 
  • Fatty Acids - Ingredients like linoleic acid, linolenic acid, oleic acid, stearic acid, palmitic acid, lauric acid, and others have various moisturizing anti-inflammatory, and barrier repairing properties.
  • Humectants - Humectants are ingredients that draw moisture towards themselves, resulting in increased moisture on applied areas. We have a full list of humectants here.
  • Occlusives - Occlusive ingredients create a thick layer on the skin that water cannot get through. Thick, saturated oils and other creamy substances are the most common occlusives. Check out our detailed list of occlusive ingredients here!
  • Oils - Oils are ingredients composed of various lipids and polyphenols based on which plants they come from. We have a full list of the most common oils in skin care here!


Most ingredients that act as fragrances are in the category of essential oils. For the most part, essential oils are very thin and watery oils that have to combined with thicker substances for good delivery in skin care. Some fragrant ingredients like rose oil do have some mild benefits in skin care. 


There are a variety of ingredient types that can help preserve skin care products. Many preservatives have fallen out of favor, so this list will include some examples that are less common than they used to be. Some common ingredient categories for preserving ingredients include:

  • Alcohols - Alcohols are antimicrobial, keeping products sterile as they sit on shelves at stores. You can read about alcohols in skin care products here!
  • Essential oils - Some essential oils, like tea tree oil and thyme oil, have natural antimicrobial properties and are used as preservatives in natural and organic skincare formulations. However, their effectiveness as preservatives can vary, and they may also pose risks of skin sensitization or irritation for some individuals.
  • Organic acids - Organic acids such as benzoic acid, sorbic acid, and salicylic acid are used as preservatives for their antimicrobial properties. They are often found in products with a more "natural" positioning and can be effective against a range of microorganisms. However, their effectiveness is pH-dependent.
  • Isothiazolinones - This class includes preservatives like methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI), known for their strong efficacy against bacteria, yeast, and fungi. However, they have been associated with allergic reactions and sensitivities, leading to restricted use in some countries.
  • Phenoxyethanol - Phenoxyethanol is a glycol ether used as a preservative in many cosmetic products. It's effective against both bacteria and fungi and is considered a safer alternative to parabens and formaldehyde releasers. It's commonly found in both skincare and makeup products.
  • Formaldehyde releasers - These preservatives work by slowly releasing formaldehyde, a potent preservative, over time. They're effective against bacteria and fungi. Common formaldehyde releasers include quaternium-15, DMDM hydantoin, and imidazolidinyl urea. Due to concerns about formaldehyde's potential health risks, some prefer to avoid these preservatives.
  • Parabens - Parabens are among the most commonly used preservatives in cosmetics and skincare. They're effective against a broad range of microbes and have been used for decades. Examples include methylparaben, propylparaben, and butylparaben. Despite their widespread use, there's ongoing debate about their safety, leading some consumers to seek paraben-free alternatives.
Skin lightening ingredients

Skin Lightening Ingredients

Skin lighteners, brighteners, and whiteners are a group of skincare ingredients that even skin tone. They may be called skin brighteners. They work by one or more of the following: block production of melanin, block transfer of melanosomes from the melanocyte to the keratinocyte, or increasing exfoliation.

PAR-2 Blockers

Proteinase-activated receptor 2 (PAR-2) is located in the connection between keratinocytes and melanocytes. It functions as a doorway to allow melanin laden melanosomes to enter into the keratinocyte after being produced by melanocytes. PAR-2 blockers prevent melanin from entering keratinocytes. Examples include niacinamide and proteins found in soy.

Tyrosinase Inhibitors

Tyrosinase is the enzyme necessary to produce the pigment melanin. Tyrosinase inhibitors block this enzyme. There are many different tyrosinase inhibitors used to treat skin pigmentation problems, such as hydroquinone, resorcinol, hexylresorcinol, vitamin C, arbutin and kojic acid.


Chemical Sunscreens

  • Aminobenzoic acid (PABA): Once common in sunscreens but now rarely used due to the potential for skin irritation and the risk of clothes staining.
  • Avobenzone
  • Cinoxate
  • Dioxybenzone
  • Ensulizole (Phenylbenzimidazole Sulfonic Acid)
  • Homosalate
  • Meradimate (Menthyl Anthranilate)
  • Octinoxate (Octyl Methoxycinnamate)
  • Octisalate (Octyl Salicylate)
  • Octocrylene
  • Oxybenzone
  • Padimate O
  • Sulisobenzone
  • Trolamine Salicylate

Physical / Mineral Sunscreens

  • Zinc Oxide: Offers broad-spectrum protection, shielding the skin from both UVA and UVB rays. Zinc oxide is often favored for sensitive skin and can be found in many "baby" sunscreen formulations.

  • Titanium Dioxide: While it also provides broad-spectrum protection, titanium dioxide is particularly strong in guarding against UVB rays.

Both of these ingredients work by sitting on the surface of the skin and reflecting away the UV rays, rather than absorbing them like chemical sunscreens. As such, they're often referred to as "physical blockers" or "inorganic sunscreens." Because of their mode of action and the fact that they don't penetrate the skin deeply, mineral sunscreens are generally considered safer for sensitive skin and have fewer concerns related to systemic absorption or potential hormonal disruption.

Skin Care Ingredient Checker

To learn about benefits and side effects of skin care ingredients, search for the ingredient name in this comprehensive skin care ingredient checker found at this link.

This is the best place to find dermatologist- recommended skin care ingredients and products that contain them.

Which ingredients are best for you in your skin care routine depends upon your Baumann Skin Type. Always shop and read product reviews based on your Baumann Skin Type.

Level up your skin care knowledge with medical advice from dermatologists

Best references on skin care ingredients:

  1. Baumann, L. Cosmeceuticals and Cosmetic Ingredients (McGraw Hill 2015)
  2. Baumann's Cosmetic Dermatology (McGraw Hill 2022)
  3. https://www.mdedge.com/dermatology/cosmeceutical-critique
  4. Baumann, L. (2006). The skin type solution: a revolutionary guide to your best skin ever. Bantam.
  5. Baumann, L. (2019). Cosmeceuticals and skin care in dermatology. U: Kang S, Amagai M, Bruckner AL, Enk AH, Margolis DJ, McMicheael AJ i sur., ur. Fitzpatrick’s dermatology, 9, 3803-19.
  6. Baumann, L., Rodriguez, D., Taylor, S. C., & Wu, J. (2006). Natural considerations for skin of color. Cutis, 78(6 Suppl), 2-19.
  7. Baumann, L. S. (2007). Less‐known botanical cosmeceuticals. Dermatologic therapy, 20(5), 330-342.
  8. Baumann, L. (2018). How to use oral and topical cosmeceuticals to prevent and treat skin aging. Facial Plastic Surgery Clinics, 26(4), 407-413.
  9. Grunebaum, L. D., & Baumann, L. S. (2014). Nonprescription topical treatments for skin rejuvenation. Facial plastic surgery, 30(01), 003-011.
  10. Monteiro, E. D. O., & Baumann, L. S. (2006). The science of cosmeceuticals. Expert Review of Dermatology, 1(3), 379-389.
  11. Baumann, L. (2016). Cosmeceuticals in skin of color. , 35, 4, 35(4), 233-237.
  12. Baumann L. Ch 14. Scientific Approach to Cosmeceuticals in Warren, R. J. (2021). The Art of Aesthetic Surgery: Principles and Techniques.

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