Bacopa monnieri: two bacoside numbers, two different methods

A 50% bacoside bacopa and a 20% bacoside bacopa can be the same material. The difference is which method was used, and it is the single most common misunderstanding in the Ayurvedic extract trade.

The two methods

UV spectrophotometry is the older approach. It measures absorbance and reports a total that captures a broad group of saponins, not just the compounds of interest. It reads high, and it is cheap, which is why it persists.

HPLC separates and quantifies individual bacosides — bacoside A3, bacopaside II, bacopaside X, bacosaponin C and others — and reports their sum. It reads considerably lower on the same sample because it is counting a defined set of compounds rather than everything that absorbs at the same wavelength.

As a rough guide, material sold as "50% bacosides by UV" often assays somewhere around 20% by HPLC. Neither figure is fraudulent. Only one of them is specific.

Why this matters commercially

A buyer comparing a 50% quote against a 20% quote will assume the first is stronger and cheaper per unit of active. If the methods differ, that conclusion is exactly backwards. This is the reason a bacopa specification must name the method before it names the number, and the reason we quote HPLC figures as standard even when it makes a quote look weaker on paper.

What else defines a bacopa extract

• Plant part — whole plant, which is conventional for bacopa, stated explicitly.
• Species confirmation. Bacopa monnieri is adulterated with, or substituted by, Centella asiatica often enough that identity testing is not optional. HPTLC fingerprint or DNA barcoding on the raw herb both work.
• Extraction solvent and residual solvent limits.
• Carrier — the excipient used to standardise down to a target percentage, declared with its proportion.
• Heavy metals and pesticides, with attention to the water source, since bacopa is a semi-aquatic plant grown in standing water.

Specify the method, then the number

Write the parameter as "bacosides NLT 20% by HPLC, sum of bacoside A3, bacopaside II, bacopaside X and bacosaponin C". That sentence is unambiguous, it is comparable across suppliers, and it makes any attempt to substitute a UV figure immediately visible.