Jelking does not work as a proven or reliable method for increasing penis size. While some men may believe that it leads to permanent enlargement, there is no scientific evidence supporting the effectiveness of jelqing. In fact, it can be potentially harmful. The increased size or engorgement that may occur after jelqing is temporary and results from increased blood flow during the process. The penis may appear temporarily larger or firmer, but this effect fades once the blood returns to normal circulation. While jelqing may temporarily increase blood flow to the penis, this effect is short-term and doesn’t result in permanent enlargement.