It seems that not all breast enhancers are permanent, some work by raising hormone levels to that of say pregnancy, giving them extra size like you would get during pregnancy and after child birth, however, just like your hormones do naturally once done breastfeeding when you stop taking the herbs they return to normal hormonal and size wise, I think this is where some of the temporary effects come in unless you keep taking the product forever to keep you hormones altered. I actually read somewhere that PM works the same way, that the effects are only supposed to be temporary, once you stop taking it they slowly return to their normal size, not sure if this is true or not, because there have been a lot of nooglers use PM, but perhaps noogling is helping to make the growth permanent as apposed to someone who isn't noogling while taking it. It would be interesting to know if any nooglers have taken PM and experienced extra growth as a result, but lost some of the growth if they stopped taking it. :-\