Milk thistle based food supplement
Extracts from the fruits of Silybum marianum Gaertn. (milk thistle) are used primarily for their hepatoprotective properties. In addition to selected authorised medicinal products, there is a large market for food supplements, some of which vary considerably in quality.
As part of the study, 15 commercially available dietary supplements were tested for authenticity using thin-layer chromatography and UHPLC with UV detection, and the silymarin content per capsule was quantified.
Conclusion: The identity testing was positive for the majority of products. However, two products stood out in terms of their composition: one contained milk thistle oil, which naturally contains no silymarin, meaning that its therapeutic benefit is fundamentally questionable. Another product contained only milk thistle seed powder in an insufficient dosage with a correspondingly low silymarin content. Furthermore, none of the samples tested achieved the declared silymarin content.
Declaration:
200 mg milk thistle extract per capsule, of which 160 mg is silymarin
Identity test: complies
Assay: 69.2 mg silymarin per unit
Declaration:
300 mg milk thistle seed oil per capsule
Identity test: Silymarin complex not detectable
Assay: /
Declaration:
80 mg milk thistle extract per capsule, of which 65 mg is silymarin
Identity test: complies
Assay: 44.5 mg silymarin per unit
Declaration:
200 mg milk thistle extract per capsule
Identity test: complies
Assay: 59.8 mg silymarin per unit
Declaration:
100 mg milk thistle extract per capsule
Identity test: complies
Assay: 42.9 mg silymarin per unit
Declaration:
250 mg milk thistle extract per capsule, of which 200 mg is silymarin
Identity test: complies
Assay: 131.1 mg silymarin per unit
Declaration:
500 mg milk thistle extract per capsule, of which 400 mg is silymarin
Identity test: complies
Assay: 193.6 mg silymarin per unit
Declaration:
500 mg milk thistle extract per capsule, of which 400 mg is silymarin
Identity test: complies
Assay: 209.5 mg silymarin per unit
Declaration:
200 mg milk thistle extract per capsule, of which 160 mg is silymarin
Identity test: complies
Assay: 91.3 mg silymarin per unit
Declaration:
500 mg milk thistle extract per capsule, of which 400 mg is silymarin
Identity test: complies
Assay: 231.8 mg silymarin per unit
Declaration:
525 mg milk thistle extract per capsule, of which 420 mg is silymarin
Identity test: complies
Assay: 252.5 mg silymarin per unit
Declaration:
250 mg milk thistle extract per capsule, of which 200 mg is silymarin
Identity test: complies
Assay: 115.4 mg silymarin per unit
Declaration:
750 mg milk thistle extract per capsule, of which 600 mg is silymarin
Identity test: complies
Assay: 440 mg silymarin per unit
Declaration:
300 mg milk thistle seed powder per capsule
Identity test: complies
Assay: 5.8 mg silymarin per unit
Declaration:
500 mg milk thistle extract per capsule, of which 400 mg is silymarin
Identity test: complies
Assay: 165.9 mg silymarin per unit