The invention relates to alpha-derivatives of cis-monounsaturated fatty acids intended for use as a drug. More specifically, the invention relates to compounds having formula I, and the pharmaceutically acceptable derivatives and salts thereof, in which (a) and (b) can have any value between 0 and 14, (X) can be substituted by any atom or group of atoms with a weight between 4 and 200 Da, and (R) can be substituted by any atom or group of atoms with a weight between 1 and 200 Da, intended for use as a drug.