Raw garlic,
does it really help with Prevention of common-cold occurrence?
research showsThe verdict is pending. A repeat search of PubMed, ClinicalTrials.gov, and Cochrane on August 3, 2026 found zero eligible human trials within the checked sources that fed culinary-dose raw garlic and measured cold occurrence. The frequently cited 146-person trial tested a stabilized-allicin capsule, not raw garlic.
ads claimOne raw clove is roughly 4 g, about 1 teaspoon, 0.33 tablespoon, or eight pinches when minced. The allicin content of the capsule used in the 2001 trial could not be confirmed, so no raw-garlic equivalent can be calculated.
Useful facts when choosing a product
- Cutting or crushing raw garlic brings alliin and alliinase together to generate allicin, but yield and stability depend on processing.
- Josling tested one daily capsule containing a stabilized-allicin preparation, not raw garlic. The verified allicin content of the 2001 trial product was unavailable, so it cannot be converted into a raw-garlic dose.
- Verdict 076 is C with 55 points for garlic supplements and blood pressure or lipids, verdict 595 is C with 40 points for fermented garlic extract, and verdict 1359 is D with 25 points for black garlic; none answers raw garlic and cold occurrence.
Chamgap Semantic Classification Code
Candidate index · review held
F.about-one-clove-of-raw-or-crushed-fresh-garlic.food.common-cold-occurrence.prevent.placeboFoods and beverages > About one clove of raw or crushed fresh garlic > Food consumption > common-cold occurrence > Occurrence-prevention claim > Placebo
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
On August 3, 2026, PubMed was searched for '(raw garlic[Title/Abstract] OR fresh garlic[Title/Abstract] OR crushed garlic[Title/Abstract]) AND (common cold[Title/Abstract] OR upper respiratory infection[Title/Abstract]) AND (trial OR randomized)', yielding zero directly eligible raw-garlic prevention trials. ClinicalTrials.gov was searched for '(raw garlic OR fresh garlic OR crushed garlic) AND (common cold OR upper respiratory infection)', also yielding zero directly eligible completed trials. The 2014 Cochrane review screened eight candidates and included only Josling's capsule trial. Josling reported no conflict of interest, but Cochrane noted that he was then employed by a garlic-supplement company. Aged extracts, garlic tablets, allicin capsules, animal studies, and in-vitro studies were excluded for formulation or endpoint mismatch.
Why this is classified as ?
No human study jointly testing the specified formulation and cold-occurrence outcome was identified, so the verdict is pending without a score.
Counterpoint. Absence of data does not refute prevention. A prospectively registered trial of culinary-dose raw garlic is needed.
Rejudgment record. Cross-check applied — Reproducible PubMed, ClinicalTrials.gov, and Cochrane searches found no eligible human trial jointly testing culinary-dose raw garlic and cold occurrence
| Endpoint | H | Hard endpoint - actual events such as death |
Stored derived and displayed grades match; this is not a current recalculation or validity check (?).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Prevention of cold occurrence by one raw garlic clove | ? | No directly eligible human trial was identified. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Reproducible literature search on 2026-08-03 | PubMed '(raw garlic[Title/Abstract] OR fresh garlic[Title/Abstract] OR crushed garlic[Title/Abstract]) AND (common cold[Title/Abstract] OR upper respiratory infection[Title/Abstract]) AND (trial OR randomized)'; ClinicalTrials.gov '(raw garlic OR fresh garlic OR crushed garlic) AND (common cold OR upper respiratory infection)'; Cochrane 'garlic common cold' | Zero directly eligible raw-garlic prevention trials | No applicable human study | Common-cold occurrence | Excluded stabilized-allicin capsules, aged extracts, tablets, animal studies, and in-vitro work because formulation or endpoint did not match. | Documents absence of direct human evidence |
| Josling P. 2001 | Double-blind placebo-controlled trial of an allicin-containing supplement | 146 randomized, 73 per group | Specific funding not confirmed; Cochrane noted that the author was then employed by a garlic-supplement company | Recorded cold occurrences over 12 weeks | 24 versus 65 recorded occurrences, P<0.001; these were not participant counts, and the study was excluded as direct evidence because the formulation was not raw garlic. | Indirect evidence from a different formulation by an industry-employed author |
Receipt — 3 References
All 3 cited sources were verified for existence at the original page (as of 2026-08-03).
Final verification and publication gate: Codex · Evidence date: 2026-08-03 · Corrections: none
Cite this verdict
[Chamgap] Raw garlic x prevention of common-cold occurrence — Evidence Grade ?. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/raw-garlic-common-cold-prevention/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.