Which supplement works better to reduce frequency of the common cold: garlic extract or vitamin c?

Ratings at a Glance

Supplement	Effectiveness Rating	Confidence Rating
Garlic Extract
Vitamin C

Effectiveness Rating: Garlic Extract vs Vitamin C

The effectiveness rating is a measure of the supplements' ability to reduce frequency of the common cold. This rating answers the question of whether or not a supplement does what it claims. The evidence backing up vitamin c is great, while the evidence backing up garlic extract is good. Vitamin C should be able to reduce frequency of the common cold more effectively, however both supplements should provide positive results.

Confidence Rating: Garlic Extract vs Vitamin C

Another factor to take into account when comparing supplements is the confidence rating. This rating is a measure of how valid each supplement's effectiveness rating is. Remember, the confidence rating is a measure of how much you can trust the effectiveness rating. This rating is based on how many studies are included in the database on a supplement's claims. Ideally, you want a high effectiveness AND confidence rating.

Both garlic extract and vitamin c have low confidence ratings. This means neither supplement has an adequate amount of research to back up this claim. A low confidence rating questions the validity of the effectiveness rating.