Dear customer, The diabetes long standing and if not properly controlled may cause diabetic neuropathy in which the autonomic nerves are affected as well.You should control the serum sugar levels to nearly normal levels. The diabetes drugs also may cause delayed erection as the side effects.you should consult your endocrinologist for the same if it needs to be changed. The stress, depression, anxiety are also very common causes of such delayed or non-erection and should be treated as well after consulting your doctor. The drugs like sildenafil, tadafil are available in market on prescription of doctor which when taken one hour before sex can help in long lasting erection. The other causes like low testosterone, depression , etc should be looked into as well. http://www.healthcaremagic.com/web/images/community/post.png Thank you!