Betamethasone is a steroid medication. It is used for a number of diseases including rheumatic disorders such as rheumatoid arthritis and systemic lupus erythematosus, skin diseases such as dermatitis and psoriasis, allergic conditions such as asthma and angioedema, preterm labor to speed the development of the baby's lungs, Crohn's disease. Betamethasone valerate; Clinical data; Trade names: Betnovate, Celestoderm, Ecoval 70, Hormezon. (11β,16β)-9-Fluoro-11,21-dihydroxy-16-methyl-3,20-dioxopregna-1. Betamethasone is a synthetic glucocorticoid with metabolic, immunosuppressive and anti-inflammatory activities. Betamethasone binds to specific intracellular glucocorticoid receptors and subsequently binds to DNA to modify gene expression.