The active ingredient you want is the curcumin. So, look at the amount of curcumin if buying turmeric. Some brands will add a black pepper or piperine to the curcumin that helps with absorption. You need to take about 4 to 5 times as much turmeric than the amount of curcumin wanted. Read the back labels. If the online seller does not show the label in a readable form, there are plenty of online sources that do. I use www.vitacost.com for most of my needs. Their house brand usually has good info.