Aveeno bath oil contains colloidal oatmeal, which is an extract from the grain of Avena sativa (oats or oatmeal). It is used in homeopathy to prepare moisturising skin preparations. The oil also contains liquid paraffin (sometimes known as mineral oil) and sunflower seed oil, and works by providing a layer of oil on the surface of the skin to prevent water evaporating from the skin surface.
Dry skin results from lack of water in the stratum corneum, which is the outer layer of skin cells. When this layer becomes dehydrated it loses its flexibility and becomes cracked, scaly and sometimes itchy. The stratum corneum contains natural water-holding substances that retain water seeping up from the deeper layers of the skin, and water is also normally retained in the stratum corneum by a surface film of natural oil (sebum) and broken-down skin cells, which slow down evaporation of water from the skin surface.
The skin dries out when too much water evaporates from its surface. This increases as we get older, and is made worse by washing, because hot water and soap remove the layer of natural oil on the skin surface.
Moisturising bath oils are useful for dry skin conditions, such as eczema and dermatitis, which get worse when the skin is allowed to dry out. Used regularly, moisturisers and moisturising bath oils help restore the skin’s smoothness, softness and flexibility by replacing lost moisture and helping the skin retain moisture. This helps reduce scaling, itching and redness.
The oil can be added to the bath water or applied directly to the skin when washing or taking a shower. After bathing using the bath oil the skin should be patted rather than rubbed dry.
In conditions such as eczema, using moisturisers and moisturising bath oils regularly, even once the skin has improved, can help prevent flare-ups.