Some milk thistle labels print a silymarin percentage, such as a standardization line. Others do not. If you are comparing bottles, it helps to know what each type of label tells you and what it leaves out. This guide uses the current VITAMIZED Daily Liver Support Capsules label as the example.
What silymarin is, in plain terms
The National Center for Complementary and Integrative Health describes silymarin as the main constituent of milk thistle extract, and as a mixture of compounds rather than a single substance. Source: NCCIH, Milk Thistle. That is why a percentage on a label, when one is printed, needs context: which compounds are counted, and how.
What this label states
Per 2-capsule serving, the Daily Liver Support label lists milk thistle seed extract: 300 mg, next to other listed ingredients and a 325 mg proprietary blend. A bottle holds 60 capsules, or 30 servings.
The label does not print a silymarin percentage. We are not going to guess one here. The 300 mg figure is the weight of the extract. It is not the weight of silymarin.
Extract weight and silymarin percentage are different lines
- Extract amount (mg) tells you how much extract is in a serving.
- Silymarin percentage, where a brand prints it, describes a share of that extract. You would need both numbers to calculate an amount.
- If only one of the two is on the label, you cannot work out the other.
Why a missing percentage matters when comparing
Say one label lists 300 mg of extract with no percentage and another lists 150 mg of extract with a percentage. They cannot be ranked from the front of the bottle. A bigger milligram number does not tell you the silymarin amount, and a percentage without the extract weight does not tell you either.
NCCIH also notes concerns that some milk thistle products have contained silymarin amounts substantially different from what the label states. That is a general point about the category, and it is one more reason to compare what is actually printed rather than assume.
Questions to ask any brand
- Is the milk thistle listed as an extract or as seed powder, and in what amount per serving?
- Is a silymarin percentage stated, and if so, how is it measured?
- What else is in the serving? On this label, the milk thistle sits alongside apple cider vinegar, artichoke leaf, dandelion root extract, choline, zinc and a proprietary blend.
- What is the serving size and servings per bottle?
Where to go next
For extract versus ground seed, read milk thistle extract vs. seed powder. If you shop by reviews, see which details matter in milk thistle reviews, or start from the milk thistle guide.
This article is about reading a label. It is not medical advice. If you take medication, are pregnant or nursing, or have a medical condition, talk with a healthcare professional before using a supplement. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
