Rice bran oil (INCI: oryza sativa) contains 16% palmitic acid, 2% stearic acid, 42% oleic acid (C18:1), 36.6% linoleic acid (C18:2), and 1.5% linolenic acid (C18:3). It contains tocopherols at 400 mg per kg of oil, which means loads of Vitamin E for your skin and lots of anti-oxidants to retard rancidity. All of this is great, but what makes rice bran oil fantastic are the unsaponifiables, which make up about 4% of rice bran oil.
The unsaponifiables in rice bran oil contain Vitamin B, Vitamin E, and squalene (0.1 to 0.7%), which we know are great for skin applications.
Rice bran oil contains about 1 to 2% y-oryzanol, a phytosterol unique to this oil. It's a mixture of "ferulic acid esters or sterols and triterpene alcohols". What does this mean? Ferulic acid is a very effective antioxidant, and the y-oryzanol has been shown to be a more effective anti-oxidant than Vitamin E (which explains why an oil with all those double bonds manages to have a shelf life of one year!). Studies are showing ferulic acid can prevent skin aging and reduce age spots. It can help with light or radiation induced damage in skin. And I've seen it written that ferulic acid can stimulate hair growth, but I haven't seen any studies showing this to be true. It will penetrate the skin to offer moisturizing and softening, help with wind chapped or sun burned skin, and help reduce itching and inflammation in the skin. Rice bran oil can be used as a very light sunscreen, but I wouldn't trust it without serious testing.
Rice bran oil is a medium weight oil with a shelf life of about a year. It's not a terribly expensive oil, which makes it fantastic for any application! You can use it at up to 100% in any anhydrous or hydrous application. If you want the linoleic acid-y goodness of sunflower oil or soy bean oil but want a longer shelf life, then rice bran oil is the oil for you! It has a similar fatty acid profile to sesame oil, but costs less. It is, however, staining to fabrics so you wouldn't want to use it in something like an after bath or massage oil for fear of ruining your fine linens!
I use rice bran oil in everything - I like to combine fractionated coconut oil, soy bean oil, and rice bran oil in a hand lotion for maximum softening and moisturizing. It's fantastic in a body butter, and great in foot creams. I can't think of a product I wouldn't use it in, except facial moisturizer (and that's because I have acne prone skin and want maximum linoleic acid in the form of sunflower oil).
Let's take a look at formulating with rice bran oil tomorrow.