I believe it does. Over the years I was able to add over an inch of permanent mid erect girth, then figured I was as large as I was going to get at 6 1/2". I was at that number for several years. Started wearing a cock ring and was amazed at what it did. First off, after a solid jelqing session I gained over a 1/2" of temporary girth, but then it would start to dissipate within a few hours. Wearing my leather cock ring (a simple 1/2" adjustable, nothing fancy) those temporary gains actually lasted for days. I believe staying in that enlarged state for longer periods of time did get me over the hump. I probably only gained around another 1/4", but considering that I am very large and had been at the 6 1/2" mark for years, I would say that is significant. I would expect lesser girthy guys to gain even more.