Corticosteroids, or steroids, are essential in treating multiple myeloma (MM). They help other drugs fight cancer cells and reduce swelling. Small amounts can be combined with injection therapies to prevent allergic reactions and control nausea and vomiting. Sometimes steroids are used alone to treat MM. They are not the hormone-like drugs some athletes use to bulk up but are synthetic versions of cortisol, a hormone produced by the adrenal glands. A common corticosteroid for MM is dexamethasone, which can be taken as a tablet or injection. While dexamethasone is commonly used, others like prednisone, prednisolone, and methylprednisolone work similarly. Steroids may be used at every treatment stage, and doctors usually prescribe based on a long-term plan. Long-term steroid use can suppress the immune system, increasing infection risk, and can lead to osteoporosis, a condition of reduced bone density, increasing fracture risk. Steroids affect bones by hindering calcium absorption and speeding up bone breakdown. Italian researchers found that reducing medication dosage or stopping steroids can safely and effectively control MM. Doctors identify patients at high risk for osteoporosis before starting steroids, using the lowest dose for the shortest time possible, or opting for other drugs.