Wide-angle lenses are a great choice for photographing environmental portraits, where you want to show a person within a specific context. However, wide-angle lenses used close-up will distort facial features and creative unflattering pictures.
A better choice for portraits is either a standard lens or a short telephoto lens. The classic portrait focal lengths for a full-frame camera are 50mm, 85mm prime lenses and a 70-200mm zoom.
These will help to compress features and provide a more natural-looking result.