Terminology might be confusing.

Concentrated supplements would be nonnutritive supplements that augment natural sources of cofactors, vitamins and micronutrients.

Often, they are provided in a format that improves absorption (ex: slow release, micellar, gel caps) and bioavailability (compounded in a fat soluble or acid resistant formulation) or stability (for example, air tight blister packs for sam-e), is in a more bioactive form than afforded in natural foods (converted forms), or is used to directly treat a known dysfunction (as in use of R-ALA, chromium, vanadium for insulin insensitivity, antioxidants for brain, liver and kidney protection during steroid use or during extended periods of heavy exertion, etc).

Nutritive supplements are intended as meal replacements. Protein shakes, energy drinks, meal replacement bars (energy and high protein)...are included in the this class.

Where classification and definition may begin to break down: amino acid supps, including BCAAs, taurine, alanine, glutamine/arginine/citulline, histamine, fish, flax and olive oils as sources of omega-3 and omega-6 fats, creatine and its alternate forms, appha GPC, ALCAR, and certain neurotransmitters, like ephinephrine stimulators (which you mention) and GABA.

This is a great topic...a difficult one to determine the best subject breakdown in the sorting and grouping of subtopics.

We need more input in this thread.