In the tests, the strength of garlic products was measured by the amount of allicin each could produce. Allicin is made when garlic is crushed or chewed and is associated with the efficacy of fresh garlic. In the tested products, allicin amounts ranged from none to over 6,000 mcg. Most products that passed the testing provided 4,000 to 6,000 micrograms of allicin per day, about the amount expected from a small clove of garlic and in line with typical dosage recommendations. Aged garlic products were evaluated based on the amount of a related compound known as SAC.
Despite garlics popularity, there is a high likelihood of a consumer being misled by the label on a garlic supplement, said Tod Cooperman, MD, president, ConsumerLab.com. There are some very high quality products out there, but it is impossible to distinguish them from rip-offs without the lab results. He gave the following examples:
Two products claimed their pills to be equal to a clove of garlic, but while one yielded a substantial 6,300 mcg of allicin, the other had only 1,630 mcg. Ironically, the weaker product claimed to be high potency.
An ultra-high potency product claimed each pill to be equivalent to 25 grams of fresh garlic, but yielded only 63 mcg of allicin instead of the expected 25,000 mcg.
A product claimed to be equivalent to a popular name-brand supplement to which it looked identical, but it had less than half of the allicin found in the popular product.
The contents in the capsules of one supplement weighed less than the amount of garlic claimed to be in them.