Eman, there is a lot to look out for here but it comes down to having a good, long, hard look at the ingredient list.
Most pre workout supps these days contain a lot of stimulants, they are very cheap to put together (assuming there is not a lot else in there) however as stimulants meet a major part in why someone takes a pre workout product, many consider them essential ingredients.
If you are purely looking for a stimulamnt and that is sole reason you take the prodct then have a think about using pure DMAA such as what we offer here:
1,3 - DIMETHYLAMYLAMINE (DMAA) - 5G
For $19 you are egtting 200 doses, so this represents extremely good vakue for money.
If you are considering a product as you want the benefit of certain aminos, creatine, arginine, beta alananine (which all provide various benefits in strength, increased endurance, N.O effect) then best ensure that these products are in there.
It does pay to look in a bit more detail and to do some searches though as although many supps contain these, they do so in such low doses that they are unlikely to have any effect.
It is always good to look at a products label, confirm how much of a key ingredient is in each dose and then do a google search from there.
As an example, most people take at least 2.5g of Beta Alanaine if they use this before training, Arginine (or AAKG, Arginine Ethyl Ester) is dosed similarly, and once you throw in Creatine you are looking at near a 10g serve.
This is the biggest issue I have with most of the new ultra concentrated formulas, they simply don't offer enough of the aminos to make them worthwhile, so you are effectively getting a stim kick.
As above, if you want a stim kick you may as well save your money and get pure caffeine or DMAA.
The Pre Workout NT we sell is (as far as I am concerned) about as complete, pure and potent as a pre workout supplement gets.
Each 10g dose has plenty of beta alanaine, citrulline malate, aakg and creatine in it, in fact it is 97% amino acids where most others are less than 70%.
At $25 for 250g it represents very good value for money compared to any of the popular U.S products.
PRE WORKOUT POWDER NT - 250G