It is a soap that has a higher ph. For some reason, when people with TMAU use regular bar soap it makes the fishy smell worse. a soap with a lower ph somehow renders the salts on the skin less fishy...i am not explaining it correctly but in general that is how works. for me, it doesn't take the fishy smell away completely, but it doesn't make it worse like regular soap did in the past. the vaginal area is very sensitive to ph changes and this soaps helps the ph in that area stay closer to normal - if that makes sense.