1 A kind of arthritis called osteoarthritis. 2  There is some clinical evidence that gelatin might relieve pain and improve joint function in patients with osteoarthritis. 3  Brittle bones (osteoporosis). 4  Strengthening bones and joints. 5  Strengthening fingernails. 6  Improving hair quality. 7  Weight loss.ome people also use it for strengthening bones, joints, and fingernails. Gelatin is also used for improving hair quality and to shorten recovery after exercise and sports-related injury. In manufacturing, gelatin is used for preparation of foods, cosmetics, and medicines.