No. At best you'll see a bit of enlargement until taking the thing off, then your dick goes back to normal. At worst they'll tear the skin on your dick. You're better off taking a multi-vitamin high in Vitamins B, E, and Iron. I'd also recommend drinking low-salt V-8 with 2TBSP of raw unfiltered apple cider vinegar and half a teaspoon of cayenne pepper in the morning, and drinking a full 64oz of water every day. And minimizing caffeine. While these won't make your cock magically "xbox heug", they will greatly help your blood circulation, which will over time assist your boners. This, plus some exercise, will also help your stamina. While size matters to an extent, being able to last long enough to give her multiple orgasms matters more.