Preventing the common cold with a garlic supplement: A double-blind, placebo-controlled survey


One hundred forty-six volunteers were randomized to receive a placebo or an allicin-containing garlic supplement, one capsule daily, over a 12-week period between November and February. They used a five-point scale to assess their health and recorded any common cold infections and symptoms in a daily diary. The active-treatment group had significantly fewer colds than the placebo group (24 vs 65,P < .001). The placebo group, in contrast, recorded significantly more days challenged virally (366 vs 111,P < .05) and a significantly longer duration of symptoms (5.01 vs 1.52 days,P < .001). Consequently, volunteers in the active group were less likely to get a cold and recovered faster if infected. Volunteers taking placebo were much more likely to get more than one cold over the treatment period. An allicin-containing supplement can prevent attack by the common cold virus.

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Correspondence to Peter Josling B.Sc..

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Josling, P. Preventing the common cold with a garlic supplement: A double-blind, placebo-controlled survey. Adv Therapy 18, 189–193 (2001).

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  • allicin
  • common cold
  • garlic supplement