I was intrigued to find, when reviewing You Being Beautiful, that the authors (two doctors) warned off using the anti-aging cosmetic ingredient DMAE because it causes cells to die. Although I don't use anything with DMAE, the claim seemed worth verifying - if only to burst Dr Perricone's bubble. DMAE is one of his much-vaunted ingredients and I have always regarded him as a pretender to the throne of anti-aging king.

I have only found one clinical study that demonstrates that the chemical 2-dimethyl-amino-ethanol (dimethylaminoethanol), commonly listed in many anti-aging cosmetics as DMAE, may cause a seriously negative reaction in skin cells. However, the research does seem be thorough, peer reviewed and published in the British Journal of Dermatology.

DMAE has historically been used as an oral supplement to help improve mental alertness. It's found naturally in fish such as sardines and anchovies and has been shown in limited studies to boost brain function and mood when ingested. As a cosmetics ingredient, it has been claimed that DMAE can help reduce wrinkles by preventing cell deterioration and shoring up cell membranes. You will find it in products by Neutrogena and Dr Perricone's Solar Protection Face with DMAE (pictured). According to Dr. P's book, The Wrinkle Cure, DMAE can prevent cell deterioration when applied topically. His Web site, http://www.nvperriconemd.com/, claims that "introducing additional DMAE into our systems" is good way to maintain an anti-aging skin care regimen.

The research that turns this claim on its head was conducted by the Faculty of Medicine at Canada's Université Laval. Tests on human and rabbit skin cells showed a drastic and rapid swelling of fibroblasts, which maintain the connection between cells. Within a few hours after applying DMAE, cell division slowed and at times stopped completely. Twenty-four hours after applying the concentration of DMAE found in anti-wrinkle cosmetics, the fibroblast mortality rate reached over 25%.
Dr. Guillaume Morissette, who co-presented the recent tests on DMAE, suggests that the so-called anti-wrinkle effect may occur as a result of the actual damage suffered by the skin. When the cell becomes damaged, the skin thickens.

"From our point of view the cells are altered. They stop dividing, they stop secreting, and after...24 hours a certain proportion of them die," Dr. Francois Marceau of the Centre Hospitalier Universitaire de Quebec told Reuters Health.

A 2007 study noted that DMAE swells the fibroblasts, creating an immediately firmer and lifted look that they, ominously, attributed to “vacuolar cytopathology” (it should be noted that this attribution is speculative). 

On the other hand, I found one small study using subjective analysis of side-by-side tests that purports to demonstrate that DMAE is an anti-ager. I have also found a Brazilian study from 2009 (two years after the Canadian one mentioned above) that confirmed that DMAE increased dermal thickness and collagen fiber thickness and noted that there was no "mechanical effect". Another study was conducted by Johnson & Johnson. After 16 weeks, subjects using a DMAE gel showed improvements in the reduction of forehead and periorbital fine lines and 35 people continued the study for an additional eight months with no adverse reactions.

UPDATE: A 2014 animal study of DMAE used in conjuction with amino acids, found that skin became thicker with increased type l and type lll collagen.