No problems of skin irritation were found with Disodium Cocoyl Glutamate (1). On the contrary, a higher enzyme activity was found after the application of SLES (which, on the other hand, has been shown to attenuate the trypsin enzyme when applied even in low concentrations and alone) together with Disodium Cocoyl Glutamate (2).

References______________________________________________________________________

(1) Corazza M, Lauriola MM, Bianchi A, Zappaterra M, Virgili A. Irritant and sensitizing potential of eight surfactants commonly used in skin cleansers: an evaluation of 105 patients. Dermatitis. 2010 Sep-Oct;21(5):262-8.

Abstract Background: Irritation from surfactants contained in detergents is a frequent adverse reaction to cosmetics. Sensitization to surfactants is also possible. In the literature, comparative studies about irritant and sensitizing potential of different surfactants are heterogeneous and inconclusive about the best molecules to use....Results: None of the eight surfactants in our series gave positive allergic reactions. Only cocamidopropyl betaine from the Italian standard (Società Italiana di Dermatologia Allergologica, Professionale e Ambientale [SIDAPA]) series gave five positive reactions among 105 patients. None of the eight studied surfactants induced skin irritation. The most tolerated are two new mild anionics (sodium cocoyl glutamate and sodium lauroyl oat amino acids) and an amphoteric agent (disodium cocoamphodiacetate).  Conclusion: From this study, we deduce that cosmetic companies' efforts to search for and market new products with very mild surfactants have been generally successful.

(2) Schepky AG, Holtzmann U, Siegner R, Zirpins S, Schmucker R, Wenck H, Wittern KP, Biel SS. Influence of cleansing on stratum corneum tryptic enzyme in human skin. Int J Cosmet Sci. 2004 Oct;26(5):245-53. doi: 10.1111/j.1467-2494.2004.00232.x. 

Abstract Desquamation in human skin is a well-balanced process of de novo production of corneocytes and their shedding from the skin surface. The proteolysis of corneodesmosomes is an important step in the final desquamation process. In the degradation of these adhesion molecules, the stratum corneum tryptic enzyme (SCTE) plays a key role. In initial studies with extracts of porcine epidermis, SCTE was shown to be inactivated by low concentrations of sodium lauryl ether sulphate (SLES). These in vitro findings were supported by in situ results obtained by measuring the release of fluorescent dyes coupled to trypsin-specific substrates incubated on human skin cross-sections. Moreover, in further studies, it could be demonstrated that the SCTE activity in the human horny layer decreases after in vivo application of cleansing products containing SLES. After repeated washing of human volunteers with tap water, a standard market cleansing product (SLES/betaine system) or a new improved cleansing product (SLES/betaine/disodium cocoyl glutamate system), the specific SCTE activity was determined in extracts from the uppermost layers of the stratum corneum. It could be shown that after application of the new formula the remaining SCTE activity was significantly higher than after use of the standard market formula. This ex vivo approach has proven to be very helpful for measuring surfactant effects on human skin enzymes. Using this assay, we developed an improved shower gel formula, which leads to a significantly higher skin enzyme activity after application, compared to a standard market formula.