Anecdotally speaking I have used both CissusRX and bulk at an extract ratio of 20:1. In terms of medicinal value CissusRX was superior in both relative and absolute terms. In addition the muscle preserving aspects of CissusRX were not present in the bulk. For me CissusRX has the same anti-catabolic effect as daily Ma Huang use without the sides.
Extracts are simply concentrated forms of what the maker "deems" to be the most important part of an herb, obtained through extracting the properties of a crude herb using a solvent. At this time bulk Cissus quadrangularis is not sold by anyone as a standardized extract. It is not manufactured, tested and guaranteed to contain a said amount of "active constituents". Therefore comparing ratios has limited value.
When we speak of extract ratios we should ask what is being extracted. Traditional herbalists argue that this process causes a loss of "other" compounds therefore degrading any synergistic actions which are still unexplained but known to happen.
It has been documented in a recent study on the anti-oxidant properties of Cissus quadrangularis that the stem part of Cissus quadrangularis contains 479 mg of vitamin C, 267 units of carotenoids, 0.73% of calcium, steroidal and phenolic substances. Phytochemical studies on the extract used in the study revealed the presence of triterpenes including a- and ß- amyrins, ß-sitosterol, ketosteroid, phenols, tannins, carotene and vitamin C. See: African Journal of Biomedical Research, Vol. 8, No. 2, 2005, pp.95-99
It is very important to note that the afore-mentioned study used properly cultivated high-grade Cissus, a vacuum drier to remove extraction solvents and a standardized freeze temperature for storage.
It is probable that USPLabs:
1. Views parts of Cissus not present in bulk as important "active constituents".
2. Has identified synergistic actions of compounds present in the whole herb but lost in typical extracts.
3. Takes measures to insure their Cissus is high-grade thus preserving easily degraded compounds.
4. Has spent more time, effort, and energy on reviewing studies and gathering a broad base of user reports than any other non-academic entity.
5. As a consequence has spent time, effort, energy and financial resources in developing their product CissusRX which differs substantially from the currently available bulk Cissus.