The Best Beauty Ingredients According to Dermatologists

A group of distinguished scientists from reputable universities recently published a paper in the prestigious Journal of the American Academy of Dermatology.¹ They report that 17 scientists, primarily dermatologists, analyzed published data relative to skin and hair treatments. They aimed at identifying cosmetic ingredients endowed with real efficacy. Seven fields of possible cosmetic activity were defined. These were clinical (not biochemical) endpoints and were: fine lines and wrinkles, redness, dark spots, acne, large pores, dry skin, oily skin. The 17 scientists established a tentative list of 318 putatively active ingredients.

What They Found

Upon discussion, 83 ingredients out of those 318 were recognized as having been recommended or prescribed in at least one of the seven domains of activity. Upon interrogating 62 dermatologists in 43 research institutes in two rounds of what is called a Delphi survey² a process was established to find a consensus about which cosmetic ingredients are endowed with what activity.

At the end of the second round of analysis, for each ingredient in the list of the 83, a consensus was found, or not found, about the “reality” of its activity. During the final “consensus” meeting, 23 ingredients across the seven cosmetic concerns reached consensus.

They are reported in Table I above.

The consensus ingredients are not surprising: they are already known to good cosmetic chemists in R&D departments of large and small companies. One might appreciate the effort of the panelists to recognize as active against redness (and therefore within the legally allowed field of cosmetic action), molecules utilized in pharmacology as antibiotic, bacteriostatic, antiparasitary or antihypertensive agents. The odd molecule out, in this set of anti-redness agents, seems to be niacinamide. It boosts DNA repair when topically applied after UV and it hinders the inflammatory response triggered by pyrimidine dimers. Niacinamide encompasses a sophisticated mechanism of action worthy of in-depth analysis.

No Consensus

More interesting is, perhaps, the recognition of ingredients that could not obtain a consensus. Panelists didn’t reach consensus on peptides, lactic acid, ceramides and growth factors being active against fine lines and wrinkles. Lactic acid, mandelic acid, polyhydroxy acid and erythromycin did not get consensus as being active against acne. Aloe vera, colloidal oatmeal, cucumber extract, green tea and hydrocortisone did not reach consensus as anti-redness agents. Alpha-arbutin and corticosteroid did not achieve a consensus as being active against dark spots. Fruit acid, malic acid, citric acid, lactic acid, azelaic acid and glycolic acid failed reaching a consensus for reducing the size of large pores. Cyclomethicone, dimethicone, mineral oil, paraffin, glycerol (!!) and glycol stearate are not supported by consensus as far as their activity against skin dryness is concerned. Last, but not least, consensus was not reached for the activity against oily skin for papaya, witch hazel, glycolic acid, mandelic acid or lactic acid.

More Questions

Other questions can arise from the reading of the paper. The consensus reached about the activity of retinoids in five out of seven domains of cosmetic activity, needs details about the retinoid in question. Retinoic acid is one, but it is teratogenic. What about the others? Adapalene? Beta-carotene? Retinol? Retinal? Are they all efficaceous in the five domains of cosmetic activity?

A good thing about the paper by Alvarez et al¹ is that it seems to have investigated ingredients that have been around for quite a while, so that the data in the literature constitute a bulky document rich in information originating from many different laboratories. 

Perhaps the authors will enter a second round of investigation to explore ingredients that are relatively newer on the market. New ingredients include Bakuchiol, Resveratrol, Gorgonian extract, Polyfucose, Acetyl Zingerone, Melatonin, Zanthalene and the likes.

Discussion

It is indeed a miracle that dermatologists across the country discussed the activity of cosmetics. Once considered an oxymoron (to many laypersons an active cosmetic appears to be a preposterous concept) cosmetic activity does exist and the interest shown by those dermatologists will encourage scientists committed to cosmetic science, to persevere in their endeavor.

Of course, the results reported by Alvarez and coworkers¹ are just a beginning. They are not complete and they provide results consistent with a medical-dermatological mindset more than with a cosmetological approach. For instance it is very surprising to the laboratory chemist, to read that glycerol is not considered active against skin dryness. 

This is probably because doctors know that pure glycerol, when topically applied, does extract water from the stratum corneum, thus making skin even dryer. But laboratory chemists know that glycerol formulated in water-based emulsions provides a great moisturization to the skin. 

I’ll discuss Alvarez’s paper further in my next columns.

References:

1. Alvarez GV et al (2025) Skin care ingredients recommended by cosmetic dermatologists: a Delphi consensus study. J. Am. Acad. Dermatol. In the press.
2. A Delphi survey, also known as the Delphi method, is a research technique used to gather and refine the opinions of a group of experts on a specific topic through a series of questionnaires and controlled feedback. It’s designed to reach a consensus view by iteratively collecting and synthesizing expert opinions, often used when dealing with complex or uncertain issues. The process typically involves multiple rounds of questionnaires, with feedback from previous rounds provided to participants to encourage convergence of opinions (from the AI answer on the internet).

Paolo Giacomoni, PhD
Insight Analysis Consulting
paologiac@gmail.com
516-769-6904

Paolo Giacomoni acts as an independent consultant to the skin care industry. He served as Executive Director of Research at Estée Lauder and was Head of the Department of Biology with L’Oréal. He has built a record of achievements through research on DNA damage and metabolic impairment induced by UV radiation as well as on the positive effects of vitamins and antioxidants. He has authored more than 100 peer-reviewed publications and has more than 20 patents. He is presently Head of R&D with L.RAPHAEL—The science of beauty—Geneva, Switzerland .