Sadly, there is no place online to stream episodes or download them. Currently, there are no DVD sets for sale

I emailed Discovery Health about this awhile ago and this was there exact response to me:
Dear Viewer:
Thank you for contacting Discovery Health Channel. We appreciate your
interest in our programs. Unfortunately, Dr. G: Medical Examiner is
currently not available for purchase or download. At this time, we do not
have any information as to when this program will be released on DVDs.
Please know that your comments are taken very seriously. Your email will
be forwarded to our executives for consideration when making decisions as
to what programs to make available for purchase.
Thank you again for expressing your interest in our programming.
Sincerely,
Viewer Relations
Discovery Health Channel
Hopefully they will start making sets to sell in stores.