Is Garlic Extract Safe with Isoniazid?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid combining Garlic Extract with Isoniazid — Garlic Extract blocks the liver enzyme (CYP2E1) that processes Isoniazid, potentially raising Isoniazid levels to toxic range. Consult your doctor or pharmacist.
Why this interaction occurs
Diallyl sulfide inhibits CYP2E1.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 17,281 reports mentioning Isoniazid. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Isoniazid + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Garlic Extract interactions → · All Isoniazid interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.