Does garlic or vitamin B repel mosquitoes?
Quick answer
No — eating garlic, taking B-vitamins, or hanging dryer sheets won’t repel mosquitoes. Every controlled trial of these home remedies has come back negative. What you eat doesn’t change the CO₂, heat, and skin odor that mosquitoes actually use to find you.
Why it doesn't work
The ingestible-repellent folk remedies — garlic, thiamine (vitamin B1), B-complex, brewer's yeast — all rest on the idea that you can change your body odor enough, by diet, to become invisible to a mosquito. The biology doesn't support it, and the controlled trials are uniformly negative.
Host-seeking females lock onto a CO₂ plume from a distance, then home in using a blend of skin volatiles — lactic acid, ammonia, carboxylic acids, 1-octen-3-ol — plus heat and humidity. The two cues that matter most at range, CO₂ and heat, are products of basic metabolism and cannot be diet-masked: you exhale CO₂ and radiate heat no matter what you ate. For an ingested compound to repel, it would have to be excreted through the skin at a concentration high enough to override that entire multi-cue system — and none of these do.
Thiamine is the most-tested. A double-blind, placebo-controlled trial (Ives & Paskewitz) found oral vitamin B gave no protection against mosquito landing or biting. Garlic was tested the same way (Rajan et al., a double-blind crossover): no significant repellent effect on mosquito landings. Dryer sheets are sometimes cited from a single study suggesting a component (linalool) repels gnats/fungus gnats in a lab dish — that’s a different insect and a contact-range effect, and it does not translate to mosquito protection in a yard.
Why do people swear by them? Individual attractiveness to mosquitoes genuinely varies — driven by skin microbiome, CO₂ output, blood type signaling, and skin chemistry — and it varies night to night, which makes any remedy you happened to try look effective. But when you control for that with blinding and a placebo, the diet effect disappears. The cues you’re found by are metabolic and chemical, set by your body, not your dinner.
References
- Ives, A.R. & Paskewitz, S.M. (2005), "Testing vitamin B as a home remedy against mosquitoes," Journal of the American Mosquito Control Association 21(2):213–217.link pending verification
- Rajan, T.V. et al. (2005), "A double-blinded, placebo-controlled trial of garlic as a mosquito repellant," Medical and Veterinary Entomology 19(1):84–89.
- Smith, J.D. et al. (regarding dryer-sheet/linalool effect on fungus gnats, not mosquitoes).link pending verification
What to do instead
The honest answer isn't "give up" — it's to target the host-seeking females directly. A CO₂ + heat trap broadcasts the breath-and-body cues mosquitoes actually follow, drawing them away from you and capturing them, without spraying pesticide across your yard.
See the SkeeterSwitch bundleCommon questions
Does eating garlic keep mosquitoes away?
No. A double-blind placebo-controlled trial found no significant repellent effect.
Does vitamin B (thiamine) repel mosquitoes?
No. Controlled trials show oral vitamin B provides no protection from bites.
Do dryer sheets repel mosquitoes?
There's no good evidence for mosquitoes. The one cited effect was on fungus gnats in a lab dish.
Why do some people seem more attractive to mosquitoes?
Real differences in CO₂ output, skin chemistry, and skin microbiome — none of which you can meaningfully change by diet.