Vitamin E is the umbrella name for a family of fat-soluble antioxidants, the most important of which is alpha-tocopherol. Your body uses it to protect cell membranes from oxidative damage, especially in tissues that handle a lot of polyunsaturated fat, your brain, your liver, your red blood cells, and the LDL particles moving through your bloodstream.
Most people don't need to supplement it. Outright deficiency is rare in anyone eating a normal diet with seeds, nuts, vegetable oils, or leafy greens. Narrow contexts where supplemental vitamin E has been shown to do something useful, mainly fatty liver disease without diabetes, and a handful of skin and mucosal conditions where topical or oral tocopherol genuinely helps. Outside those contexts, the evidence for taking it as a daily "antioxidant for general health" is weak to neutral, and at high doses it actually carries downsides. This page is mostly about helping you figure out whether you're in one of the narrow contexts where it's worth taking, or whether you're better off getting it from food and moving on.
For most people taking vitamin E as a general supplement, you should expect to feel nothing. There's no acute or subjective effect, no energy lift, no mood change. It's working at the level of membrane oxidation, which you can't perceive.
In NASH, the expected outcome is histological improvement on biopsy at 1-2 years and a fall in ALT and AST. You won't feel the difference directly, you'll see it on bloodwork and imaging.
For skin, expect nothing from pure topical tocopherol on scars or wounds, and a meaningful chance of contact irritation. The skin benefits of vitamin E are real but come from formulated antioxidant products (typically with vitamin C and ferulic acid), not from puncturing a capsule onto your face.
If you're taking it as insurance against heart disease or cancer, expect the same outcome as placebo. The randomised evidence is clear on this.