What attracts mosquitoes to humans, and why does one person at the barbecue come home covered in lumps while the person next to them walks away untouched? Everyone has a theory about blood type, sweet blood, garlic or a vitamin tablet. Some of those theories have real research behind them, some have a little, and some have none at all. This guide goes through the published studies one by one, says what each of them actually tested, and is upfront about where the evidence is thin.
What attracts mosquitoes to humans: the cues they follow
A female mosquito looking for a meal is not relying on a single signal. A 2015 review in the journal Current Biology by Ring Cardé lists the cues available to a mosquito hunting a person: exhaled carbon dioxide, "a plethora of skin odors," the host's visual and heat signatures and, once she is close, moisture (Cardé, "Multi-Cue Integration: How Female Mosquitoes Locate a Human Host," Current Biology, 2015). In other words, she works through a chain of clues, from a breath plume at distance to warmth and smell up close.
That matters for the "why me?" question, because every link in the chain can differ from one person to the next. Two people standing side by side give off different skin chemistry, run at slightly different temperatures and breathe differently. A mosquito that has several cues to compare is, in effect, choosing between menus.
It also explains why a single trick rarely changes much. If you only alter one cue, the others are still there.
Are some people really more attractive to mosquitoes?
Yes, according to repeated laboratory work. A study in Medical and Veterinary Entomology (Qiu and colleagues, 2006) collected skin emanations from 27 volunteers on glass marbles and tested them against the malaria mosquito Anopheles gambiae. The authors reported "clear differences" in attractiveness between volunteers, and consistent differences when the three most and three least attractive were compared pairwise. They found no effect of gender or age in that group (Qiu et al., Medical and Veterinary Entomology, 2006).
A 2013 review in the Annual Review of Entomology by Willem Takken and Niels Verhulst puts this in a wider setting. They describe host preference in mosquitoes as having a genetic basis, while being "characterized by high plasticity" that depends on which hosts are around (Takken and Verhulst, "Host preferences of blood-feeding mosquitoes," Annual Review of Entomology, 2013). Put plainly, mosquitoes have preferences, but they are not rigid ones. If you are the only person in the garden, you are the menu.
Is it genetic? What the twin study found
One of the most quoted studies on this question compared twins. Researchers led by Fernández-Grandon tested hand odours from identical and non-identical twin pairs against Aedes aegypti mosquitoes in a two-choice assay. The odours of identical twins were highly correlated in attractiveness, while non-identical twins were correlated significantly less. The authors reported a narrow-sense heritability of 0.62 for relative attraction (Fernández-Grandon et al., "Heritability of attractiveness to mosquitoes," PLoS ONE, 2015).
Two cautions. First, this was a laboratory assay using hand odour and one mosquito species, not a person sitting outside at dusk. Second, "heritable" is a statistical statement about a group, not a prediction about you. What the paper supports is the idea that something detectable in body odour runs in families. It does not tell you which chemicals are responsible, and it does not give you a number for how many bites to expect.
Skin bacteria and body odour
Body odour is not made by skin alone. Bacteria living on the skin help turn sweat and other secretions into the volatile compounds mosquitoes can smell. A study by Verhulst and colleagues in PLoS ONE compared people who were highly attractive to Anopheles gambiae with people who were poorly attractive. The highly attractive group had "a significantly higher abundance, but lower diversity of bacteria" on their skin (Verhulst et al., "Composition of human skin microbiota affects attractiveness to malaria mosquitoes," PLoS ONE, 2011).
The same research group had earlier shown, in Malaria Journal, that volatiles produced by cultured foot bacteria attracted these mosquitoes in olfactometer and trapping experiments (Verhulst et al., "Cultured skin microbiota attracts malaria mosquitoes," Malaria Journal, 2010). These are findings about one African malaria mosquito. They do not automatically carry over to the mosquitoes you meet in a British garden, though they do show that the smell of skin is a moving target rather than a fixed trait.
Blood type, the favourite myth that is only half a myth
Blood group O is the one everyone has heard of. The research is real but narrower than the folklore. In a study published in the Journal of Medical Entomology (Shirai and colleagues, 2004), 64 human landing tests with Aedes albopictus, the Asian tiger mosquito, found that people with blood group O attracted more mosquitoes than other groups, but were only significantly more attractive than people with blood group A. The authors also reported that the antigens they tested "did not, in general, influence the landing preference" among the blood groups (Shirai et al., Journal of Medical Entomology, 2004).
So the careful reading is this: one study, one species, a modest difference between two specific groups. It would be a stretch to tell anyone with group A that they can relax. Equally, it would be a stretch to say that blood type decides who gets bitten.
Pregnancy, beer and other things researchers have measured
Some of the clearest findings are about situations rather than people. A study in The Lancet (Lindsay and colleagues, 2000) compared pregnant and non-pregnant women in The Gambia. Over three nights, the huts of pregnant women collected a mean of 6.33 Anopheles gambiae per night against 3.1 for non-pregnant women. The authors pointed to increased heat and increased release of volatile substances from the skin as the two physiological factors underlying the difference (Lindsay et al., "Effect of pregnancy on exposure to malaria mosquitoes," The Lancet, 2000).
Another study, from Burkina Faso, tested alcohol. Lefèvre and colleagues used a Y-tube olfactometer to compare volunteers before and after drinking either beer or water. Water had no effect, while beer consumption increased attractiveness. Interestingly, exhaled carbon dioxide and body temperature did not explain the beer result in that study (Lefèvre et al., "Beer consumption increases human attractiveness to malaria mosquitoes," PLoS ONE, 2010). It was a small experiment (25 beer drinkers and 18 water drinkers), so read it as an interesting pointer rather than a rule for your next summer evening.
What about vitamin B and other things you can swallow?
The pill route is the most common hope: a vitamin, garlic or a supplement that makes you unappealing from the inside. For vitamin B, there is at least a direct test. Ives and Paskewitz, writing in the Journal of the American Mosquito Control Association in 2005, noted that vitamin B is "often recommended in the popular media" as a systemic repellent. They tested larger groups of volunteers than earlier work and found "no effect of vitamin B supplementation" on how attractive skin volatiles were to mosquitoes (Ives and Paskewitz, "Testing vitamin B as a home remedy against mosquitoes," 2005).
That is a single supplement, tested in a laboratory, and we would not stretch it into a verdict on every product on the shelf. For other oral products, the honest summary is that we found no good evidence in the sources we checked that swallowing them changes how often you are bitten. Absence of evidence is not proof of anything, but it is a poor basis for spending money, and the study above also found that people differ a lot in attractiveness whatever they take.
What you can do with all this
If you cannot choose your genes or your skin bacteria, the practical lesson is to work on what you can change. Mosquitoes are most active around dusk in many places, standing water is where they breed, and covering skin removes the target. Our guide to how to prevent mosquito bites in humid weather covers the day-to-day habits, and the explainer on what smells mosquitoes dislike looks at the scent side of the question. If you are not sure what bit you, the UK biting insects field guide helps you tell a mosquito bite from a midge or horsefly bite.
On the bites themselves, the NHS describes mosquito bites as "usually small, raised and itchy" and says insect bites "are not usually serious and get better in a few days," though they can occasionally become infected (NHS, Insect bites and stings, page last reviewed 1 June 2023). If a bite looks infected or you feel unwell, speak to a pharmacist or GP.
Misaj, a Paris based skincare brand, makes a daily moisturiser called Glow Protect. On its product page, as of 15 October 2026, the brand describes it as combining "hydration, skin barrier support and botanical mosquito protection in a single cream designed to be worn daily," with "a natural aromatic blend that helps deter mosquitoes." It is a skincare cream, and the full ingredient list is published on the Glow Protect product page if you like to read a label before you buy.
The short version
What attracts mosquitoes to humans is a stack of cues: breath, heat, skin odour and, in some studies, things like genetics, skin bacteria, pregnancy and alcohol. The evidence is strongest that people differ, and weakest on any simple fix. If someone claims a single blood type, vitamin or food explains everything, ask which study they mean, which mosquito it was tested on and how many people took part.
Frequently asked questions
What attracts mosquitoes to humans most?
Researchers describe a combination of cues: exhaled carbon dioxide, skin odours, heat, visual signals and moisture at close range (Cardé, Current Biology, 2015). No single cue explains it on its own, which is why individual differences are hard to pin down.
Do mosquitoes prefer certain blood types?
One study of Aedes albopictus found that blood group O attracted more mosquitoes than other groups but was only significantly more attractive than group A (Shirai et al., 2004). That is one species and one study, so it is not enough to make a firm rule.
Does vitamin B stop mosquito bites?
A 2005 study tested vitamin B supplements on larger groups than earlier work and found no effect of supplementation on how attractive skin volatiles were to mosquitoes (Ives and Paskewitz). For other supplements, we found no good evidence either way.
Why do I get bitten more than my friends?
Studies suggest that skin odour, skin bacteria and possibly inherited factors all vary between people (Qiu et al., 2006; Verhulst et al., 2011; Fernández-Grandon et al., 2015). Researchers cannot yet tell you exactly which factors apply to you.
Sources (fetched 2026-10-12; the product page re-checked 2026-10-15)
- Cardé RT, Multi-Cue Integration: How Female Mosquitoes Locate a Human Host, Current Biology 25(18), 2015 (cue list: CO2, skin odours, visual, heat, moisture). https://pubmed.ncbi.nlm.nih.gov/26394099/
- Qiu YT et al., Interindividual variation in the attractiveness of human odours to the malaria mosquito Anopheles gambiae s. s., Medical and Veterinary Entomology 20(3), 2006 (27 volunteers, clear differences, no gender or age effect). https://pubmed.ncbi.nlm.nih.gov/17044878/
- Takken W, Verhulst NO, Host preferences of blood-feeding mosquitoes, Annual Review of Entomology 58, 2013 (genetic basis, high plasticity). https://pubmed.ncbi.nlm.nih.gov/23020619/
- Fernández-Grandon GM et al., Heritability of attractiveness to mosquitoes, PLoS ONE 10(4), 2015 (twin study, narrow-sense heritability 0.62). https://pubmed.ncbi.nlm.nih.gov/25901606/
- Verhulst NO et al., Composition of human skin microbiota affects attractiveness to malaria mosquitoes, PLoS ONE 6(12), 2011. https://pubmed.ncbi.nlm.nih.gov/22216154/
- Verhulst NO et al., Cultured skin microbiota attracts malaria mosquitoes, Malaria Journal, 2010. https://pubmed.ncbi.nlm.nih.gov/20017925/
- Shirai Y et al., Landing preference of Aedes albopictus on human skin among ABO blood groups, secretors or nonsecretors, and ABH antigens, Journal of Medical Entomology 41(4), 2004. https://pubmed.ncbi.nlm.nih.gov/15311477/
- Lindsay S et al., Effect of pregnancy on exposure to malaria mosquitoes, The Lancet 355(9219), 2000. https://pubmed.ncbi.nlm.nih.gov/10859048/
- Lefèvre T et al., Beer consumption increases human attractiveness to malaria mosquitoes, PLoS ONE 5(3), 2010. https://pubmed.ncbi.nlm.nih.gov/20209056/
- Ives AR, Paskewitz SM, Testing vitamin B as a home remedy against mosquitoes, Journal of the American Mosquito Control Association 21(2), 2005. https://pubmed.ncbi.nlm.nih.gov/16033124/
- NHS, Insect bites and stings, page last reviewed 1 June 2023. https://www.nhs.uk/conditions/insect-bites-and-stings/
- misajskin.com, Glow Protect product page (brand wording quoted verbatim, checked 15 October 2026). https://misajskin.com/products/glow-protect