Two numbers can appear on an arjuna certificate, and they are doing entirely different jobs. One tells you how much extract you have. The other tells you what the extract is. Most specifications ask for the first and assume it delivers the second.
Two Questions, Not One
Every botanical specification is trying to answer two separate questions:
- Identity — is this the plant it claims to be?
- Strength — how concentrated is the active fraction?
On some botanicals a single marker answers both, because the marker is both characteristic and abundant. On arjuna it does not, and the conventional specification quietly conflates them.
What the Tannin Assay Measures
Arjuna bark is rich in hydrolysable tannins — casuarinin, punicalagin-type constituents and related polyphenols. Assaying them gives a reasonable measure of how thoroughly the bark has been extracted and concentrated.
As a strength measure it is serviceable. As an identity measure it fails on two counts.
It is not species-specific
Tannins are ubiquitous in bark. The related Terminalia species that grow alongside arjuna — T. tomentosa, T. crenulata — are also tannin-rich, as are many unrelated barks. All of them can meet a 40% specification.
It is method-dependent
This is less widely appreciated and causes real commercial confusion. Tannin content varies substantially with the assay used:
| Approach | What it responds to |
|---|---|
| Titrimetric (permanganate-type) | Total oxidisable polyphenols — broad response |
| UV / colorimetric (Folin-type) | Total phenolics, calibrated to a standard |
| Protein precipitation | Tannins specifically, by their defining behaviour |
The same batch of arjuna extract can yield materially different tannin figures depending on which method is run. A quotation comparison that does not match methods is not a comparison. This is why we name the method on every certificate, and why we ask buyers to tell us theirs.
What the Triterpenoid Profile Measures
The constituents characteristic of Terminalia arjuna are pentacyclic triterpenoids:
- Arjunolic acid — the best known, and the practical marker of choice;
- Arjunic acid and arjungenin — structurally related, part of the pattern;
- Arjunetin — the triterpenoid glycoside.
Run by HPLC against authentic reference material, the pattern of these constituents — not merely the presence of one — is what distinguishes arjuna bark from bark that resembles it on a tannin figure.
Note the emphasis on pattern. A single marker peak can be matched by coincidence or by addition. A characteristic profile across several related constituents is considerably harder to counterfeit and is what a fingerprint comparison is actually looking at.
Why Not Standardise on Arjunolic Acid Instead?
A fair question, and the answer is practical rather than principled.
The triterpenoids occur at low percentages in the bark, so an arjunolic-acid-standardised grade is a different and more expensive product than the tannin-standardised material the market is built around. Most formulations are dosed on the conventional basis, and switching the standardisation basis without switching the dose changes the product.
Our position is therefore not that the industry should abandon tannin standardisation, but that the marker profile should be reported alongside it — strength on one line, identity on another. That gets you both answers without disrupting a dosing convention that works.
Writing the Specification
A specification that does both jobs reads roughly like this:
| Line | Requirement | Job |
|---|---|---|
| Species | T. arjuna by binomial | Declaration |
| Identity (TLC) | Corresponds to reference | Identity |
| Marker profile (HPLC) | Corresponds to T. arjuna reference | Identity |
| Tannins | NLT 40%, method named | Strength |
| Part | Stem bark only, wood excluded | Composition |
| Acid-insoluble ash | NMT 2% | Cleanliness |
Grades and What Changes Between Them
Across our grades, the identity controls stay constant and only the strength basis moves:
- 40% tannins — the standard commercial grade;
- 50% tannins — for low-dose formats and concentrated blends;
- Native ratio (10:1 / 20:1) — full-spectrum, where the formulator wants the whole bark profile rather than a concentrated fraction;
- Water-soluble — spray-dried for beverage and effervescent formats.
Every one of them carries the same species confirmation and marker profile, because identity is not a grade feature.
The Practical Summary
If you take one thing from this: ask what method produced the tannin number, and ask for the marker profile beside it. Those two requests, added to a specification that currently says tannins NLT 40%, close most of the gap between buying arjuna and buying bark.
SV Botanica reports both on every batch. See the full arjuna extract specification or request a sample.
Source Bark-Only, Marker-Profiled Arjuna Extract from India
Terminalia arjuna stem bark extract · species confirmed, wood excluded · arjunolic acid marker profile by HPLC · tannins method-stated · CoA-backed · samples for qualified buyers