I would just take it solo first. Here is the info on dosage straight from the manu.
StimulantX is a powerful and revolutionary product. In fact, some people may find it too strong at first. To get the full energy-boosting, mood-enhancing, appetite-suppressing benefit of StimulantX, please follow these directions.
We recommend beginning by taking one capsule in the morning, with food. If that’s too strong, wait a day and repeat the process, taking one every other day until your body adapts, at which point you may increase to one per day.
On the other hand, if one capsule isn’t strong enough, try taking two capsules in the morning, with food. If that’s too much, dial it down to two every other day.
You’ll soon reach the point where StimulantX delivers 8-12 hours of clean, jitter-free energy and also has an immediate suppressive effect on your appetite. You’ll feel absolutely fantastic and your mood will be great. That’s when you’ll know you’ve found the right dose.