Macrene at Ayla

Dr. Macrene Alexiades, a board-certified dermatologist with a clinical practice on Park Avenue in New York, is recognized worldwide as an authority on dermatology, laser surgery, and cutting-edge skincare ingredients. She holds BA, MD, and PhD degrees from Harvard and is an Associate Clinical Professor at Yale.

We are always delighted to host Dr. Macrene Alexiades-Armenakas, one of the most well-respected dermatologists in the country, at our San Francisco studio; each time, we learn volumes about the latest developments in skincare. During her visit to Ayla in November 2018, this self-admitted "chemical-phobe" shared her updated list of top cosmetic ingredients to avoid. Read on for her list of no-nos.


PARABENS have been shown unequivocally to mimic estrogen; they can have an impact specifically on breast cancer and prostate cancer development.

PHTHALATES have been linked to birth defects.

SULFATES can cause irritation and accumulate in groundwater.

GMOs can be harmful to health on a number of different levels, and possible effects include inflammation and allergies.

TALC can cause acne.

MICA can also cause acne; and, depending on the source, it could have been mined by underage laborers.

PROPYLENE GLYCOL has been added to the North American standard series for contact dermatitis. It’s not necessary to use it and could cause irritation.

FRAGRANCE is another ingredient that isn’t necessary and can cause irritation. I also find that essential oils aren’t well tolerated by many people.

ANIMAL- OR HUMAN-DERIVED PRODUCTS: There are a number of animal-derived ingredients that pervade skincare. What many people don’t realize is that there’s a chance that you could contract some type of disease from them, which makes them unsafe in my opinion. Such ingredients include hydrolyzed collagen or elastin, which come from animal source; placenta, which comes from a female placenta; and TNS, which comes from foreskins.

MINERAL OIL & PETROLATUM are both very acnegenic and can plug the pores. I suggest avoiding oils in general. Oils make skin look great for a little while, but in some cases, after a few months the follicles start to get over-filled with oil, causing acne. And it tends to be cystic acne that scars.

CYCLOPENTASILOXANE has been shown to cause hazards with the people who work with it. In contrast, dimethicone has been FDA indicated for 24-hour hydration, and it’s a large molecule so it doesn’t penetrate into tissue. It’s an excellent ingredient for primers and doesn’t block pores.

OXYBENZONE, AVOBENZONE & BENZOPHENONES are chemical sunscreens that can cause hormone disruption.

ALUMINUM has been linked to Alzheimer's.

2-METHOXYETHANOL is a solvent that has proven toxicity.


HYDROQUINONE has been banned in Japan because it is a toxin that creates damage to cells. We use amino acids in the 37 Actives formulas to brighten skin instead, and these are healthy.

TOLUENE is an ingredient often included in nail polishes that can cause birth defects.

TRICLOSAN is an ingredient you often see in antibacterial soaps. It's a hormone disruptor and it's also bad for the marine environment. 


About Dr. Alexiades-Armenakas: Macrene, who holds a BA, MD, and PhD from Harvard, is a Diplomate of both the American and European Boards of Dermatology and Associate Clinical Professor at Yale University School of Medicine. She runs a dermatology, laser surgery and research center in Manhattan and a lab-based skin care research company. Dr. Alexiades-Armenakas has numerous publications and discoveries in the fields of basic science, dermatology and laser surgery. Her practice and academic work are focused on topical dermatologic anti-cancer and anti-aging therapies, laser technology and skin rejuvenation. Learn more about Macrene’s impressive background here, and shop the 37Actives lineup here.

Any topic discussed in this article is not intended as medical advice. If you have a medical concern, please check with your doctor.