The short answer
Yes, there is evidence of an interaction. Two people with HIV on darunavir had darunavir levels fall below the effective range, and the virus came back (viral rebound). Their doctors linked this to garlic, and one of them ate about 15 cloves a week, so garlic in food was involved, not only supplements. In healthy volunteers, three weeks of garlic caplets cut saquinavir levels by about half.
The saquinavir study gave saquinavir without the booster ritonavir, so the size of the effect may differ in boosted regimens. If you take HIV medicines, tell your HIV doctor about any garlic supplements and about eating a lot of garlic, and ask whether your viral load should be checked.
Atazanavir is sold in India as Atavir and Virataz, and lopinavir with ritonavir as Lopimune.
At a glance
| What was seen | How it may work | Direction | Evidence |
|---|---|---|---|
| Darunavir levels too low, with viral rebound, in two patients who consumed garlic[1][3] | Not established | Less darunavir; HIV may stop being controlled | Case report |
| Saquinavir exposure down about half with garlic caplets (healthy volunteers)[2] | Lower absorption from the gut; not pinned down | Less saquinavir in the blood, still low 10 days after garlic stopped | Small clinical study |
No listing is not a clearance. A missing interaction here never means a combination is safe.
The evidence, study by study
Two case reports, 2017 Case report
Doctors described two people with HIV whose darunavir levels fell below the effective range, followed by viral rebound, a return of measurable virus in the blood. Both were linked to garlic, and one patient ate about 15 cloves a week. The published report has no abstract; these details are as Memorial Sloan Kettering's herb guide summarises them. Two cases cannot tell us how often this happens.[1]
Study in healthy volunteers, 2002 Small clinical study
Ten healthy volunteers took saquinavir three times a day, then garlic caplets twice a day for three weeks. Saquinavir exposure (AUC) fell 51%, its peak level 54% and its eight-hour level 49%. Ten days after the garlic stopped, levels were still only 60 to 70% of where they started. Saquinavir was given on its own, without ritonavir, and the garlic content of the caplets is not stated in the summary.[2]
What your doctor may watch for
- Viral load, which is how the two darunavir cases came to light.[1]
- Drug levels, where your HIV clinic can test them.[1]
What to tell your prescribing doctor
You can read this out, or show them this page:
“I take HIV medicines (names and doses), and I take garlic (supplements or capsules, and roughly how much garlic I eat in food). Garlic has been linked to low darunavir levels and viral rebound, and it lowered saquinavir levels in a study. Should my viral load or drug levels be checked?”
Withheld until review
Questions people ask
Does this apply to every HIV medicine?
Not in the same way. The study measured saquinavir without ritonavir, and the darunavir reports are two people, so the size of the effect on other regimens is not known. Ask your HIV doctor about your own combination.[2][1]
Would taking garlic at a different time from my HIV tablets help?
No study has tested a time gap. In the saquinavir study, drug levels were still low ten days after the garlic was stopped, so timing is not something to rely on without your HIV doctor.[2]
Related
Garlic and isoniazid (TB medicine)
Not tested in people. In rabbits, two weeks of garlic extract cut isoniazid levels in the blood by more than half.
InteractionGarlic and blood thinners (warfarin, aspirin, clopidogrel)
Health agencies warn garlic supplements may raise bleeding risk. Two small studies on warfarin found no effect, but they cannot rule out rarer bleeding.
InteractionGarlic (lahsun) and blood pressure medicines
Aged garlic extract lowered blood pressure further in people already on BP medicines whose pressure was still high. It adds to the drugs' effect.
InteractionPippali, black pepper and rifampicin (TB medicine)
Piperine, the compound in pippali and black pepper, is added to one Indian TB capsule to boost rifampicin. Adding it yourself is untested.
Sources
- Cloarec N, Solas C, Ladaique A, Tamalet C, Zaegel-Faucher O, Bregigeon S, Canet B, Cano CE, Poizot-Martin I. Sub-therapeutic darunavir concentration and garlic consumption; a «Mediterranean» drug-food interaction, about 2 cases. Eur J Clin Pharmacol. 2017;73(10):1331-1333. PMID 28699073.
- Piscitelli SC, Burstein AH, Welden N, Gallicano KD, Falloon J. The effect of garlic supplements on the pharmacokinetics of saquinavir. Clin Infect Dis. 2002;34(2):234-238. PMID 11740713.
- Memorial Sloan Kettering Cancer Center. About Herbs: Garlic, herb-drug interactions.
Updated 4 November 2026
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