I am a long time sufferer of allergies. I tried grapeseed extract, and have had a dramatic decrease in allergy attacks since.
I have lived with cats all of my life, which is probably why I developed an allergy to them about 3 years ago. Every time I came home from college, the cat dander would make my eyes swell up and my nose run so much that it was hard to sleep at times. I tried taking Claritin, but it barely helped. Then I tried taking two grapeseed pills every day when I woke up and when I went to bed. Almost immediately I could tell a difference. Now whenever I go home, I take grapeseed extract every day and my allergies bother me much less.