Oral administration of L-arginine in pharmacological doses induces growth hormone and insulin-like growth factor-I responses and stimulates nitric oxide synthesis. Growth hormone and insulin-like growth factor-I are important mediators of bone turnover and osteoblastic bone formation, while nitric oxide is a potent inhibitor of osteoclastic bone resorption. Because of this dual effect on physiological regulators of bone remodeling, L-arginine could potentially increase bone formation over bone resorption, and, consequently, increase bone mass. It is, therefore, hypothesized that oral supplementation of L-arginine may be a novel strategy in the prevention and treatment of osteoporosis. Studies of this simple, safe, and inexpensive therapy seem warranted.