Bex, garlic supplements do not contain the same active substances as fresh garlic, namely, allicin and S-allyl cysteine, and that may be the difference. The components in fresh garlic naturally help boost your body's glutathione levels. I think shelf life for garlic after it's been cut or crushed is only a week or so... best to mince it up just prior to eating.

Here's a pretty link for you so mr hesham doesn't have a fit about the fact that these grocery items work better than the products he $$$ssselllls.

http://www.glutathione-report.com/blog/index.php/2005/03/12/garlic-cysteine-and-your-health/

and I know that you know how to do the rest of your own research yourself, albeit having been hopelessly stranded in your chair on your island by the dental profession yourself.