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Length of Sickness

Length of sickness is the duration of which symptoms of a cold or infection persist, and reducing the duration of sickness is said to be a pro-immunity effect. Supplements may either be a daily supplement or taken on an as-needed basis.

Kamal
Research analysis lead by Kamal Patel
All content reviewed by Examine.com Team. Published:
Last Updated:

Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect length of sickness
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The mo re evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
grade-a Echinacea Notable Very High See all 6 studies
Although a high variability exists, the meta-analysis has concluded a 1.4-day reduction in sickness when it occurs relative to placebo. As echinacea is also a comparator for sickness, this reduction in notable
grade-b Colostrum - Very High See all 4 studies
Despite tenuous evidence suggesting a reduction in the frequency of sickness with colostrum, when sickness does occur there is no benefit of colostrum in reducing how long it occurs for.
grade-c Andrographis paniculata Notable - See study
Seems to be one of the few compounds able to reduce the length of sickness when taken at the first signs of sickness. The lack of a reference drug to compare Andrographis limits the strength of the evidence
grade-c Garlic Minor - See study
The length that one is sick for is only modestly reduced with garlic supplementation even at higher doses.
grade-c Vitamin C  

All comparative evidence is now gathered in our ​A-to-Z Supplement Reference.

The evidence for each separate supplement is still freely available ​here.