The pH of Skin

The surface of human skin has a naturally acidic pH in the range from 4-6, probably averaging 4.7. This acidic nature of skin is called the acid mantle and is vital for the proper functioning of skin. The low pH helps to protect the skin from bacterial infection, protects the barrier function of skin and helps the skin enzymes function properly. If the pH varies greatly, skin problems arise which may include infection, dehydration, dermatitis, roughness, acne, irritation, and noticeable flaking.

For a refresher, the pH refers to the concentration of hydrogen ion. It is a logarithmic scale that goes from 1-14 with 7 being neutral, less than 7 acidic and higher than 7 alkaline (basic). The pH of a solution can be measured with a pH meter, pH of skin is more difficult to measure and requires more specialized equipment. Read more here.

 What can affect the skin's pH?

The most common thing that we do that can change the pH of the skin is cleansing the face with soap or other cleansers that have a high pH. Healthy skin can come back to its normal pH after a few hours, but not all skin can tolerate that challenge. Face toners are often used after cleansing to restore the skin pH back to acidic. Toners should always have an acidic pH for that reason. I like to use herbaldistillates/hydrosols for a toner.  Modern face cleansers though are typically not soap and are buffered to be an acidic pH. Soap however has a basic pH of about 10 which cannot be changed, that may work great on most of your body, but if you have problems with skin on the face, do not use soap there. You can find a good face cleanser here that is pH balanced to skin.

People have often asked me about cleaning their face with baking soda. This is a big no no because baking soda has a high pH between 9-10 (similar to soap) and is sure to disrupt the pH balance of skin due to its alkalinity. Even plain tap water can affect skin pH. Theoretically, tap water should be pH 7, but it is typically closer to pH 8 because of impurities.

Age also affects skin pH, increasing as we age. For this reason it is important that products for mature skin have a pH from 4-5. Skin moisture, sweat, sebum, anatomic site, and genetic predisposition also affect skin pH.

The skin's pH is maintained by secretions from the glands of the skin; both eccrine and sebaceous secretions.

Understanding the anatomy and function of skin can help you be a better formulator. If you would like to learn more, download our ebook “The Nature of Skin.”

Winter Skin Care

In Colorado winter is brutal on the skin. The arid conditions dry the skin, cause chapped hands and lips, and even dryness on areas that don't see the sun. Here are a few tips to help this winter:

1. Drink plenty of water. It will go to the skin to moisturize.
2. Use a mild cleanser in the shower. Some cleansers are harsh and can remove the skin's oils. Most handcrafted soaps are a good choice as they contain a good amount of natural oils. And don't overwash; soap up the personal areas, feet and underarms in the shower. Water may be enough for the rest.
3. Apply body oil or moisturizer immediately after showing while the skin is still damp. This will help lock in that moisture.
4. Don't take too long or too hot of a shower. Both can strip the skin of its natural oils.
5. Try using a salt scrub in the shower. Removing dead skin cells can help the oils soak into the skin better. And its easier in the shower to get to those dry spots. 
6. Wear gloves when going outside to protect your hands.
7. Make sure to get good oils in your diet. These oils help form the barrier function of the skin and hold water in. Olive oil is a good one, use it on your salads and vegetables.

Some people tend to use heavier balms and butters in the winter, the type that do not contain water like a lotion or cream does. Remember that 'moisture' means 'water' so to moisturize your skin you really need a cream or lotion that can actually bring water to the skin. An all oil product can coat and protect the skin from loosing water but cannot add water  to the skin.