S-allyl cysteine: how much counts as enough

For aged garlic extracts, most labels list S-allyl cysteine somewhere between 0.5 mg and 2 mg per serving, and 1.2 mg is a common figure for a 500 mg capsule. That's the number to read. The 500 mg on the front is the extract weight, and it includes water-soluble solids, carbohydrates and the amino acids that make up most of the powder.

The gap between 500 mg and 1.2 mg is not a scandal. It's how the material works. Aged garlic is a fermented preparation, and S-allyl cysteine is the small, stable, water-soluble fraction that survives the process.

Where the S-allyl cysteine number sits on the label

It belongs on the Supplement Facts panel, under the ingredient line, printed per serving. The panel format means you read across: ingredient name, quantity, then the percent daily value column, which will sit blank for most garlic entries because no daily value has been set.

If the compound weight appears on the front and S-allyl cysteine appears nowhere, that's a gap. Call or email and ask for the figure. A brand that has a CoA in hand can usually quote it in a day. A brand that can't quote it probably doesn't have one.

Bigger front numbers do not mean more of the compound

A 1,000 mg capsule can carry less S-allyl cysteine than a 500 mg one if the extract is less concentrated or diluted with filler. Ratio matters more than mass. Two products at 500 mg can differ by a factor of four in the compound, which is exactly the kind of thing that doesn't show up in a side-by-side comparison of the front panels.

Powder, capsule and liquid all report per serving, and serving sizes drift. One brand's serving is two capsules; another's is one. Multiply before you compare, or you'll be judging a 240-count bottle against a 120-count one on the wrong basis.

What the compound is studied for

The published work on S-allyl cysteine is mostly on the ingredient, not on finished products, and it leans towards antioxidant activity and cardiovascular function markers. Standardisation exists precisely so a capsule delivers a reproducible amount of a named compound rather than a variable scoop of powder. That's a quality claim, not a health claim, and the two get blurred constantly in this category.

Odour-free garlic products exist because the fermentation converts the harsh sulphur compounds. The trade is that the conversion also produces the S-allyl cysteine, so the same process that removes the smell is the one that creates the compound you're paying for.

On a work trip last spring I left a bottle of aged garlic extract in a hotel room in Lisbon and replaced it at an airport pharmacy with whatever was on the shelf. The replacement was 1,000 mg per capsule with no compound figure listed anywhere. I took it for eight days and had no way of knowing whether I'd changed my intake or just my bottle count. That's a fairly ordinary experience in this aisle.

The limit here is real. Nobody can hand you a target number and promise it means something for you personally. Milligram figures on a garlic label describe what's in the capsule, and that's a narrower claim than most marketing implies.

How to compare two bottles quickly

Find S-allyl cysteine on both panels. Note the serving size in capsules. Divide the compound figure by the number of capsules if you want a per-capsule number, then multiply by how many you'd actually take each day. That gives you milligrams per day, which is the only figure that's comparable across products.

Once you have that, price per day becomes meaningful too. A 120-count bottle at $24 sounds expensive until it works out to $0.40 a day against a 60-count bottle at $15 that comes to $0.50.

The front of the bottle sells the extract. The panel sells the compound. Spend your attention on the panel.