Having a true allergy to grapes is very unusual. Most individuals who do have a true allergy to grapes are able to take Vináli.   However, the best precaution is to take one Vináli daily for a week to be sure you do not react to it. The Chief Medical Advisor for Ariix, Dr. Strand, has only seen two cases where his patients had a true grape allergy and also reacted to grape seed extract. So it is possible; however rare.   Also, most individuals who have a grape allergy do not have a serious reaction to them. Therefore, it is reasonable to try just one Vináli daily to be sure that you do not experience any reaction.   If you are already taking the Optimals and tolerating them, remember they include 100 mg of grape seed extract already. Therefore, it is even less likely that you would react to the Vináli. As always, we recommend you to consult with your physician first if you are uncertain about taking any of our products.