Been having great sex then one day It became weak my erection Doctor suggest cialis I'm 38

Hi i would go with what your Dr said , been on them  ,THEy WORK , Please Enjoy

You don't say how long you have been having this problem.  Weak erections (or worse - none at all) can be caused by many things, such as medication, stress, and fatigue.  These can usually be resolved or resolve themselves.  In other cases, there can be more serious causes that may be harder to resolve.  I am not a doctor, but 38 seems to be young to be having the normal problem that comes with age.  I think I would see a urologist, assuming the doctor you have seen is not one.  The male reproductive system is more complex than most men realize.  Medications such as Cialis and Viagra usually help with the common erection problems, but they can have side effects and they will not cure the basic problem.  They are also very expensive.