Is 3000 mg of garlic too much? i am cleansing my liver but i want to make sure it will have no side effects.

Liver cleansing???: How do you know your liver needs cleansing? And what about all the rest of us who don't "cleanse" our livers? Cleansing your liver is like cleansing your colon--neither is necessary and there is no valid medical basis for either. That much garlic is probably not a problem (emphasis on probably), but cleansing your liver is definitely not needed (emphasis on definitely)! you're young and healthy!

It depends: This depends on the form you're using. The world health organization recommends 2-5g of fresh garlic, 0.4-1.2g of dried powder, 2-5mg of oil, 300-1, 000mg of extract, or other formulations corresponding to 2-5mg of allicin (a constituent for which garlic is standardized). So if you mean fresh garlic, you're within these limits.