Celluraid What is the estimated time frame to get a 1-4 inch increase? Well, of course the results will vary for all men, but the typical time frame for performing natural penis exercises is 3-8 weeks ... and since this is natural, any results you gain will last for life. Celluraid If your penis is only 5 inches tall, then I have bad news for you - about 80 percent of women choose a man who is well-endowed.