As you have noticed, the sulfates all have polar heads which are negatively charged, and this is very important. Proteins within your skin, that play a crucial role in maintaining an effective barrier and even the physical appearance of your skin such as collagen have a net positive charge.
Similar to how a magnet works (Well, actually nothing like a magnet works, if you really want to read up on how surfactants affect protein denaturing, you can read it by click on this link but to keep things simple….), opposites attract. Ionic surfactants such as SLS, strongly binds to the positively charged and the hydrophobic residues of proteins through its sulfate groups and alkyl chains, respectively, affecting how the protein folding/unfolding occurs.
Yep, I can see I’ve lost you here but the short of it is, ionic surfactants are considered biologically “harsh” surfactants because they typically bind to & modify protein structures and for this purpose is often used in laboratories to disrupt cellular structures. Skin aging as a result of sun exposure is believed to occur because of cellular structure disruption, manifesting itself in the well-known skin burn.
In other words, Ionic surfactants such as SLS, SLES & ALS causes premature skin aging. Studies have verified that this ingredient can be damaging. In the International Journal of Toxicology, researchers noted that it had a “degenerative effect on the cell membranes because of its protein denaturing properties,” and that it could cause skin irritation and corrosion. Researchers later wrote, “The longer these ingredients stay in contact with the skin, the greater the likelihood of irritation, which may or may not be evident to the user.”
They add in their discussion of the study that the ingredient was found to cause “severe epidermal changes” where it was applied, and that it could also damage the hair follicle (when used in hair-care products). Even worse—a solution containing 1.5% sodium Lauryl Sulfate caused acne! The researchers wrote: “These two problems—possible hair loss and pimple formation—along with proven irritancy, should be considered in the formulation of cosmetic products.”