It is also worth mentioning that sarcopenia, being a progressive process and a new geriatric giant, has many contributing factors—not only the aging processes (including hormone dysregulation: sex hormones, GH, IGF1, TSH, and insulin resistance; motor neuron loss; mitochondrial dysfunction), but also vitamin D deficiency, diet (including malnutrition or undernutrition), sedentary lifestyle (physical inactivity or immobility), diseases, drug treatments (secondary sarcopenia) and drug interactions. This evidence concerns the gene IGF1 and sarcopenia.