Although not essential to health, scalp hair can be important to self-image and hair loss or alopecia may lead to significant psychological distress. Some degree of hair loss is relatively common following bariatric surgery, usually occurring 3 months or more after surgery and affecting around athird of all patients. The precise causes of post-bariatric hair loss are unknown; factors including changes in nutritional status and the impact of surgery upon the hair growth cycle are thought to be involved. In most cases, hair will begin to regrow without intervention once weight has stabilized.