LavendarRott made a suggestion to me that worked wonders. Salmon oil. You can buy it at Walmart in the over-the-counter herbal remedy section (it's for people, but it works for dogs as well). I give my Dane 2000 units per day (gelcaps), and her shedding is now less than half what it was.
I don't know what kind of dog you have, what size, etc. So I don't know what dosage would be proper. Maybe LavendarRott can tell you. All I can tell is that it works!