S-allyl-L-cysteine
SAC · standardized to 1%
The marker compound for aged garlic and the one most of the human research is standardized against. Water-soluble, well absorbed, and studied for cardiovascular and antioxidant support.†

The process
Nothing is added. Whole bulbs sit at controlled heat and humidity while their own enzymes rearrange the chemistry — sugars caramelize, allicin breaks down, and S-allyl-L-cysteine accumulates. Rush it and you get brown garlic. Skip it and you get heartburn.
Virtually absent in fresh garlic. Aging converts γ-glutamyl-S-allyl-cysteine into SAC, reaching several times the raw concentration.
The unstable, odorous sulfur compounds behind garlic breath and reflux are converted into stable, water-soluble ones.
| Property | Raw garlic | Fermented 90 days |
|---|---|---|
| Signature compound | Allicin — unstable, degrades quickly | S-allyl-L-cysteine — stable, water-soluble |
| SAC content | Trace amounts | Several times higher |
| Antioxidant capacity | Baseline | Markedly increased |
| Texture & taste | Firm, sharp, sulfurous | Soft, sweet, faintly balsamic |
| Odor on the breath | Pronounced, hours long | None |
| Tolerance on empty stomach | Often burns | Generally well tolerated |
What's inside
Fermentation doesn't concentrate one thing. It produces a family of related compounds, each studied for something different.
SAC · standardized to 1%
The marker compound for aged garlic and the one most of the human research is standardized against. Water-soluble, well absorbed, and studied for cardiovascular and antioxidant support.†
Formed only during aging
The brown-black pigments created as sugars and amino acids react over the 90 days. They carry much of the extract's antioxidant character and cannot be added in — only grown.†
Incl. S-1-propenyl-cysteine
The wider sulfur family that survives aging, including S-1-propenyl-cysteine — present only in traces in raw garlic and studied for immune-modulating activity.†
Concentrated by fermentation
Plant antioxidants that climb sharply as the bulb ages. They're a large part of why fermented garlic outperforms raw garlic on antioxidant assays.†
The label
One active ingredient and one capsule material. Most garlic supplements list a proprietary blend and a fresh-bulb equivalence with no standardization behind it — which tells you nothing about what you're actually swallowing.
Ours states the extract weight, the extract ratio, and the standardized SAC content separately, because those are three different numbers and only one of them matters for dosing.
† Daily Value not established.
Other ingredients: hypromellose (vegetable capsule).
Contains no: gluten, dairy, soy, egg, sugar, artificial colors, flavors, or preservatives.
Compare
Garlic powder, garlic oil, odorless garlic, and aged black garlic are four different things sold under one word. Here's where ours sits.
| TheraLab Fermented Black Garlic | Typical garlic capsule | |
|---|---|---|
| Active marker | Standardized 1% SAC, stated in mg | "Allicin potential" or unstandardized |
| Processing | 90 days controlled heat & humidity | Dried and milled, or briefly heated |
| Odor & repeat | None — compounds already converted | Common, or masked with enteric coating |
| Stomach tolerance | Generally fine without food | Often causes reflux or burn |
| Batch testing | Every batch, COA on request | Rarely published |
| Ingredient count | One active, one capsule | Blends, binders, flow agents |
What to expect
Aged garlic is a slow supplement. The clinical work runs 8–12 weeks, and so should your expectations. Here's roughly how customers describe it.
Weeks 1–2
Weeks 3–5
Weeks 6–12
Month 4 and on
I've taken garlic capsules on and off for a decade and always gave up because of the burps. Three months on this one and there's genuinely nothing — my wife would tell me. Whether it's doing more than that I can't say, but I'm actually taking it every day now, which is more than I managed before.
She mentioned it at my last checkup and I went looking for something with an actual SAC number on the label rather than a vague milligram count. This was one of the few. Easy to swallow, no stomach issues taking it before breakfast. I'll know more at my next appointment.
Weeks one and two I felt nothing and nearly wrote it off. Somewhere around week five I noticed I wasn't hitting the 3pm wall as hard. Could be coincidence. Docking a star because it isn't cheap, though the three-pack price is fair.
Reviews reflect individual experience and are not typical or guaranteed results.
The guarantee
A 30-day supply isn't long enough to judge a supplement like this, so we give you forty-five. If you're not convinced, email us within 45 days of delivery and we'll refund unopened packs once they're returned. Return shipping is the customer's responsibility.
Questions
No. Standard garlic capsules are usually dried, milled garlic sold on "allicin potential" — allicin being an unstable compound that degrades quickly and causes most of the odor and stomach irritation. Black garlic is whole garlic aged for months, which converts that chemistry into stable compounds like S-allyl-L-cysteine. Same plant, different product.
It shouldn't. The volatile sulfur compounds responsible for garlic breath are largely converted during the 90-day aging, which is the main practical reason people switch to aged garlic in the first place.
Be patient. Most human research on aged garlic extract runs 8 to 12 weeks, and the effects it measures are gradual ones — the kind you notice in a lab result rather than in an afternoon. Customers who report a subjective change usually describe it somewhere around weeks four to six. If you want a fair trial, plan on three months.
Ask your doctor or pharmacist first — that's not a formality here. Garlic preparations can interact with blood thinners such as warfarin, some blood-pressure medications, and certain HIV medications, and are usually stopped before surgery. Bring the label to your appointment; the SAC content is printed on it.
We don't recommend it without your doctor's sign-off. Garlic is fine as food during pregnancy, but concentrated extracts haven't been studied enough in pregnancy or breastfeeding for us to make any claim about them.
Because they measure different things, and plenty of brands blur them deliberately. You get 1,000 mg of actual extract per serving. That extract is concentrated 6:1 from fresh bulbs, so it's derived from the equivalent of 6,000 mg of fresh garlic. The number that governs the dose is the standardized one: 10 mg of S-allyl-L-cysteine.
Email us within 45 days of delivery and we'll arrange a return. Unopened packs are refunded in full once we receive them; return postage is paid by the customer. Opened packs can't be refunded, for hygiene reasons.