What Causes Oily Skin?

Many people think they have oily skin when, in fact, they don’t. One study demonstrated that people are often wrong about if they are oily or not. Often they judge whether their skin is oily just after cleansing, however, everyone feels dry for 15- 20 minutes after cleansing. Any evaluation of your skin’s sebum production needs to be done 20 minutes after cleansing to get an accurate result. Another reason that people may think they are oily when they actually have decreased sebum production is because they might just be using the wrong skincare products. Incorrect skincare products can damage the skin barrier and without excessive sebum production, this can lead to dehydration of the skin. I developed a Validated Questionnaire for Determining Skin Oiliness, which is an integral part of the Baumann Skin Type Questionnaire® so that doctors can accurately assess their patients sebum production and prescribe the correct products for their patient’s skin. This blog post will talk about the science of oily skin, but your first step is to determine if you are truly an oily skin type. Once you receive the proper Baumann Skin Type Diagnosis and are certain that you have oily skin, you should aim to understand more about sebum (oil) and the causes of oily skin. This will make it easier to manage. If your skin is oily in summer and dry in the winter- you may have combination skin. Click here to learn about combination skin.

What Is Sebum?


Oily skin is characterized by abundant sebum secretion from the sebaceous glands. These glands are found predominantly in the T-zone, as well as on the chest and back. While the exact function of sebum is not fully understood, it is known to play important roles in the three-dimensional organization of skin surface lipids, prevention of water evaporation from the skin’s surface, and as an occlusive moisturizing agent. Sebum also protects the skin against free radicals because it naturally contains vitamin E, a powerful antioxidant known to combat skin aging as well as the cellular damage that leads to skin cancer.

Sebum is actually Latin for “fat,” which makes sense because researchers have found that sebum contains triglycerides, diglycerides, fatty acids, wax esters, squalane and cholesterol. Every square inch of your skin, with the exception of the palms of the hands, soles of the feet, and lips, produces sebum. A lack of sebum and its protective vitamin E may be why the lips are more prone to skin cancer.

What Causes Oily Skin?

Although everyone’s skin produces sebum, some skin types naturally produce more than others, hence oily and dry skin. Many factors influence sebum production. Genetics, hormones, stress, diet, time of day and climate all contribute. Patients may complain that they are oilier in humid weather, however, there is no evidence that seasonal changes have an effect on sebaceous gland activity. The skin may appear to be oilier in more humid weather due to the sebum becoming more fluid, and therefore more bothersome, but the actual amount of sebum produced does not change.

One very interesting study published in the British Journal of Dermatology, which examined 20 pairs of identical and non-identical (but same sex) twins, found a surprising difference between sebum production and acne severity. While each pair of identical twins had nearly the same rate of sebum production, the acne severity between the two individuals greatly varied. On the other hand, the sebum production of the non-identical twins was vastly different between each individual of the pair, as was acne severity. The study concluded that “sebum excretion is under genetic control and the development of clinical lesions is modified by environmental factors.” Thus, genetics and environmental factors such as stress and diet can have a significant influence on skin oiliness and the development of acne.

What Does Oily Skin Mean in the Baumann Skin Typing System?

The Baumann Skin Typing System is an excellent tool for determining the unique characteristics of your skin, but this typing system goes much further than simply classifying skin as either oily or dry. Upon completing the Baumann Skin Type Questionnaire®, you will have an “O” or “D” score, which corresponds to how oily or dry your skin is. This score is then combined with three additional characteristics to produce your unique Skin Type. Of the 16 Baumann Skin Types, eight are oily and eight are dry.

Once you know your Baumann Skin Type, you can much more easily and effectively choose the best skincare products to help you restore and maintain a healthy complexion. Visit to find a physician who can accurately diagnose your skin type and prescribe the most effective skincare regimen.

Oily skin can be bothersome, but remember that sebum is actually good for the skin because it helps prevent moisture loss and contains high levels of antioxidants. The secret to managing oily skin is using the correct skincare products to minimize its challenges.


Dr. Leslie Baumann, M.D. and her team at Baumann Cosmetic Dermatology believe in proof, not promises. World-recognized for both cosmetic and general dermatology, our treatment strategies rely exclusively on evidence-based, scientifically verified products and procedures that promote skin health and a natural appearance. We combine effective medical procedures with individualized instruction on proper skincare, nutrition, supplementation and lifestyle in order to maximize the health of the skin and body as a whole while minimizing the effects of aging. For more, visit Dr. Baumann’s blog for daily updates Monday through Friday, or inquire about an appointment through

January 20, 2017 Acne