I guess unless u test them, there's no way to guarantee they are real. Are they particular brand? Is your source reliable? Can you ask your source what brand they are?. Some sources will break open original packaging if you aren't ordering a complete "unit" of whatever they have. If they are real but underdosed then you'd need more to "feel it" -- its sort of a personal experiment as to how much is "enough" because of all the above reasons - not everything is dosed the same, not everyone has the same tolerance, etc. Normally you'd start at what is your smallest unit (e.g. 1 tab) and then increase in a controlled manner - e.g. 1 in the am, 1 in the pm, 2 in the am, 1 in the pm, 2 in the am , 2 in the pm - to determine where is your tolerance and go specifically by what your body tells you. If you feel nothign - you didn't increase your dose but you also don't know what it is you are taking,. LIke I said - it is not uncommon for a source to repackage stuff -that points to the good practice of using a source that only sends packaged stuff. So other than getting it tested or not using it at all, you need to establish a level of assurance that you are comfortable w/ that what youg ot is real. You can look at photos of a variety of real / counterfeit pills if you spend some time or if you know what the brand is.