Height is primarily determined by genetics and whether your growth plates have fused, which typically occurs by late adolescence. No over-the-counter supplement can safely increase your height. To improve your physical fitness and support any remaining natural growth, focus on a balanced diet rich in protein, calcium, and Vitamin D, get 8-10 hours of sleep daily, and engage in regular exercise. I highly recommend consulting a pediatrician or endocrinologist. They can perform a simple X-ray to see if your growth plates are still open and run blood tests to check for any underlying hormonal or nutritional deficiencies before recommending any medical interventions.