For many reasons it is best to avoid bar soap, especially from the neck up, but it can also be helpful to avoid it from the neck down. Although this is particularly true if you have problems with dry skin or breakouts, there are issues with using most bar soaps or bar cleansers no matter what type of skin you have.
Some people believe that the tight sensation they feel after washing with soap means their face is clean; tight like you almost can’t open your mouth without feeling your skin stretch. The thinking is that the more squeaky-clean your face feels, the better off you are. Yet the feeling you associate with being clean is nothing more than irritated, dried-out, and stressed skin. The difficulty with asking someone to break a soap habit is that soap really does clean the skin thoroughly. Unfortunately, it cleans too thoroughly, and ends up causing irritation and all the associated skin problems that come with irritating the skin (Source: Skin Research and Technology, July 2001, pages 49-55).
The major issue with bar soap is its high alkaline content (meaning it has a high pH). “The increase of the skin pH irritates the physiological protective ‘acid mantle’, changes the composition of the cutaneous bacterial flora and the activity of enzymes in the upper epidermis, which have an acid pH optimum” (Source: Dermatology, March 1997, pages 258-262). That technical description basically explains that skin’s normal pH is about 5.5, while most bar soaps have a pH of around 8 to 10, which negatively impacts the surface of skin by causing irritation and increasing the presence of bacteria in the skin. There is definitely research showing that washing with a cleanser that has a pH of 7 or higher, which is true for many bar soaps and bar cleansers, increases the presence of bacteria significantly when compared to using a cleanser with a pH of 5.5. (Sources: Clinics in Dermatology, January-February 1996, pages 23-27; and Dermatology, 1995, volume 191, issue 4, pages 276-280.)
What about specialty soaps that come in clear bars, have nonsoap-sounding names, or contain creams and emollients that appear to have none of the properties of regular soap? Bar cleansers (and technically they’re not soap) often have a lower pH and are therefore far less irritating to skin. However, the ingredients that keep the bar cleanser in its bar form can theoretically absorb into skin and clog pores. There is also no convenient way for a consumer to test each particular bar to be sure the pH is compatible with skin. Further, many of the so-called gentle bar cleansers I’ve reviewed contain fairly drying, irritating, and potentially pore-clogging ingredients. So much for specialty soaps being different! Worse yet, the soaps designed for oily or acned skin contain even harsher ingredients. Soaps designed for dry and sensitive skin often contain beneficial ingredients such as glycerin, petrolatum (mineral oil), or vegetable oil, and while they might make the face feel somewhat less stiff after you rinse, and reduce the irritation potential, the skin still doesn’t need the ingredients that hold the soap in its bar shape. (Sources: InternationalJournal of Cosmetic Science, August 2008, pages 277-283; and International Journal of Dermatology, August 2002, pages 494-499.)
Here’s a rundown of some basic categories of soaps. Remember, just because a product is advertised as soap doesn’t mean it is.
Castile soaps use olive oil instead of animal fat, but the cleansing agent, sodium hydroxide, is still fairly irritating to the skin.
Transparent soaps look milder or less drying because of their unclouded, clear appearance, but many contain harsh cleansing ingredients, can still have an alkaline pH, and the ingredients that give the bar its shape can clog pores.
Acne soaps often contain very irritating ingredients in addition to harsh cleansers that, especially when combined with other acne treatments, can super-irritate the skin. There is no reason to overclean the skin. Breakouts have nothing to do with how clean your skin is! A study in Infection (March-April 1995, pages 89-93) demonstrated that “in the group using soap the mean number of inflammatory [acne] lesions increased…. Symptoms or
signs of irritation were seen in 40.4% of individuals______ ” Furthermore, if the acne cleanser
contains antibacterial agents, the benefit would be washed down the drain, though there is research showing the cleansers containing benzoyl peroxide can have benefit but they were not in soap form (Source: Journal of Drugs in Dermatology, May 2006, pages 442-445).
Cosmetic soaps or bar cleansers are sold at the cosmetics counters for far more money than they are worth. Although these are advertised as being gentle or specially formulated, they are no better than or different from what you can buy at the drugstore. The irritating and pore-clogging ingredients are still included regardless of the price or claim.
Superfatted soaps contain extra oils and fats that supposedly make them gentler for the face. Basis soap is one of the most popular superfatted specialty soaps. However, the extra glycerin, petrolatum, or beeswax in these soaps won’t prevent irritation and can cause breakouts.
Oatmeal soaps are supposed to be better at absorbing oil and soothing sensitive skin than other soaps or bar cleansers. There are studies demonstrating that oatmeal can have antiirritant properties. How that translates into a bar cleanser is unknown, but the benefits are probably nonexistent given the amount of time the oatmeal is actually on the skin and the presence of other irritating ingredients. Plus, the oatmeal particles are fairly large and end up usually being more abrasive on skin, and that isn’t gentle in the least.
“Natural”soaps are those that contain vitamins, fruits, vegetables, plants, flowers, herbs, aloe, and specialty oils; these ingredients are gimmicks and serve no purpose when it comes to cleansing the face. They don’t nourish the skin or provide any other health benefit—that is sheer marketing whimsy and nothing more. Plus, the cleansing agents and the ingredients that keep the soap in bar form are the same as in any other bar cleanser.
Beauty bars and Syndet cleansers such as Dove are about 50% sodium cocoyl isethionate (a form of coconut oil) and, although it is not as irritating as other cleansing agents found in soaps, it is still potentially irritating and drying, especially in such a high concentration. Dove claims to be moisturizing, and it does contain emollients to help soften the effect of the cleansing agent. If the manufacturers left out the drying and irritating ingredients altogether, they wouldn’t need to add emollients to counteract them. Also, the ingredients that help the bar keep its shape can clog pores. Dove is a better bet than most bar cleansers but can still create an uphill battle for getting the skin you want (Source: Cutis, May 2006, pages 317-324).