Garlic supplements and foods: how much allicin reaches the body
What it found
In 13 healthy people, how much allicin the body actually gets varied widely between garlic supplements and garlic foods.
Enteric-coated tablets gave less when taken with a high-protein meal, while cooked and acid-treated garlic foods gave more than expected.
What they found
Studies in people
Enteric tablets
Enteric-coated tablets gave 36 to 104% of the raw garlic control when taken with a low-protein meal. With a high-protein meal, this dropped to 22 to 57%, because the stomach emptied more slowly.
Non-enteric tablets and capsules
Non-enteric tablets gave high values of 80 to 111% regardless of the meal. Garlic powder capsules ranged widely, from 26 to 109%.
Kwai tablets
Kwai garlic powder tablets, used in many clinical trials, gave 80% of the raw garlic control. The authors say this supports using them to represent raw garlic in those trials.
Cooked and acid-treated foods
Garlic foods with no active alliinase gave more than expected: boiled 16%, roasted 30%, pickled 19%, and acid-minced 66%. Black garlic gave 5%.
Enzyme activity
How much allicin reached the body did not track with the enzyme activity in the tablets. The authors say only a minimum level of enzyme activity seems to be needed.
Other findings
Lab test vs. body
A standard lab dissolution test only partly agreed with what was measured in people. The authors say this test is not fully accurate for predicting what happens in the body.
What the authors conclude
“In conclusion, these largely unexpected results (lower ABB for enteric tablets and higher ABB for all other products) provide guidelines for the qualities of garlic products to be used in future clinical trials and new standards for manufacturers of garlic powder supplements.”
Also in their conclusions
- They say these largely unexpected results provide guidelines for the qualities of garlic products to be used in future clinical trials and new standards for manufacturers of garlic powder supplements.
- They also say the results give the consumer an awareness of how garlic foods might compare to the garlic powder supplements used to establish any allicin-related health benefit of garlic.
How it was done
The authors wanted to know how much allicin from different garlic products actually reaches the body, because this has been unknown and in question. They say this matters for interpreting clinical trials and for giving shoppers and manufacturers better guidance.
They gave 13 garlic supplements and 9 garlic foods to 13 healthy people (6 women, 7 men, aged 26 to 62) and measured a garlic breakdown product in their breath over 32 hours. Each product was compared with a control of homogenized raw garlic, which was set at 100%.
What it can’t tell you
- This was a small study of 13 people, so the numbers may differ in a larger group.
- The study measured a garlic breakdown product in breath, not health outcomes like cholesterol or blood pressure.
- It cannot say whether any garlic product improves health, only how much of this marker reached the body.
Who paid
- Conflicts
- The authors declare no conflict of interest.
The paper
- Title
- Allicin Bioavailability and Bioequivalence from Garlic Supplements and Garlic Foods
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Lawson LD, Hunsaker SM (2018). Allicin Bioavailability and Bioequivalence from Garlic Supplements and Garlic Foods. Nutrients. doi:10.3390/nu10070812Free full textPubMed 29937536DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error