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I've heard of parasites that can live in the human body and do a lot of damage to the host. There are even safer forms of worm-like parasites inside the intestine, but some parasites can live in the blood vessels or even in the brain or eyes.

Parasites are, in my opinion, the most disgusting creatures there are, so I wondered if they could be killed with intoxication. Would it be possible to get rid of worm parasites in the blood by increasing the amount of alcohol in the blood to a level that humans can tolerate but parasites can't? Could you also eliminate brain parasites with hangover-related brain dehydration?

That the dead parasites remain in the body may not be good or advisable. In addition, eggs, which are usually a little more resilient, should rather be removed from the body by antibiotics or proper medication. But is it at least theoretically possible to do something with alcohol against parasites?

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    $\begingroup$ Welcome to SE Biology. Have you done any literature research about the permeability of parasites to different substances? I must be honest and say that it seems rather naïve to think that you have come up with a solution that has eluded the thousands of highly trained parasitologists working for years on this topic. There may be a parasitologist on this list who can tell you why your idea is wrong (as it surely must be), but it would be more useful for you to do some research yourself. $\endgroup$ – David Dec 13 '19 at 14:27
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    $\begingroup$ The principle is sound, but alcohol won't do it. (I think because a high enough blood alcohol level to kill the parasites would kill you, too.) There are a number of anti-parasite medicines out there, the most common of which is probably ivermectin: en.wikipedia.org/wiki/Ivermectin In the US, at least, it's readily available at any feed store, or on-line, as it's widely used for livestock. $\endgroup$ – jamesqf Dec 13 '19 at 18:37
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    $\begingroup$ In dogs they used to use arsenic to kill the worms. It was extremely debilitating to the animal. $\endgroup$ – DatsunZ1 Dec 13 '19 at 20:12
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    $\begingroup$ The term "antibiotics" generally refers to substances that act against bacteria, and "parasites" generally refers to animals. $\endgroup$ – Acccumulation Dec 14 '19 at 17:20
  • $\begingroup$ A G&T might do the trick against malaria! But that is only because the tonic contains quinine, an anti-malarial compound. $\endgroup$ – James Dec 16 '19 at 13:22
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In summary, there is no convincing evidence to say that alcohol intoxication helps to treat or prevent parasites in humans.

1) The evidence from in vivo human studies does not support the idea that alcohol consumption helps in treating parasites.

Alcoholism and Strongyloides stercoralis: Daily Ethanol Ingestion Has a Positive Correlation with the Frequency of Strongyloides Larvae in the Stools (PLoS, 2010):

The frequency of Strongyloides was significantly higher in alcoholic patients than in control group (overall prevalence in alcoholic 20.5% versus 4.4% in control group; p = 0.001).

2) Even a strong alcohol beverage gets diluted when it reaches the intestine.

Ethanol concentrations in the human gastrointestinal tract after intake of alcoholic beverages (European Journal of Pharmaceutical Sciences, 2016):

In a cross-over study, five fasting volunteers were asked to drink two standard consumptions of commercially available alcoholic beverages, including beer (Stella Artois®, 500 mL, 5.2% ethanol), wine (Blanc du Blanc®, 200 mL, 11% ethanol) and whisky (Gallantry Whisky®, 80 mL, 40% ethanol).

The median gastric ethanol Cmax (min–max) for the beer, wine and whisky conditions amounts to 4.1% (3.1–4.1), 4.1% (2.6–7.3) and 11.4% (6.3–21.1), respectively...Median duodenal ethanol Cmax (min–max) for beer, wine and whisky are 1.97% (0.89–4.3), 2.39% (2.02–5.63) and 5.94% (3.55–17.71), respectively.

So, the maximal ethanol concentration in the duodenum after drinking 80 mL of whisky was 17.7%. Most of ethanol is absorbed in the first part of the small intestine (Scandinavian Journal of Gastroenterology), so it does not reach the more distant parts and does not likely kill the parasites there.

3) Even strong intoxication is associated with low blood alcohol concentration.

In strong intoxication, your blood alcohol concentration would be only 0.2-0.3%. In one study (Table 1), the 50% lethal concentration (LC50) of ethanol, which killed 50% of the bloodstream forms of the parasites Trypanosoma brucei, was 10.6%.

4) Alcohol intoxication and brain dehydration

Alcohol intoxication or hangover are not automatically associated with dehydration. Anyway, even in severe dehydration, you still have a lot of water in your body, including the brain, so the parasites living there do not necessarily get dehydrated as a result of your dehydration.

In general, dehydration increases the risk of infections, because it dries mucous membranes, for example in the urinary tract (BMJ Open Quality, 2019).

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    $\begingroup$ I don't think I'll ever drink alcohol again. No, but seriously, parasites are really creepy. It's good to know that I can't do anything against parasites with alcohol and would even have a higher risk of infection. So thank you for the good answer. $\endgroup$ – Roybin93 Dec 14 '19 at 14:16
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    $\begingroup$ The PLOS study applies only to chronic alcoholics and the effect of ethanol consumption is very likely to be secondary and nothing to do with the the anti-parasitic effect of ethanol (and it concerns only a single parasite). As the authors acknowledge, the correlation may be due to a compromised immune system or merely poor hygiene. This is not what the OP is asking. It is well known that fruit-flies use ethanol as an anti-wasp agent ref and other species (including humans) may similarly benefit at least in some cases? $\endgroup$ – user1136 Dec 14 '19 at 20:59
  • $\begingroup$ @user1136, the OP asked if alcohol can kill parasites. I have found that single in vivo human study, which does not support this idea. No matter how weak or poorly related this evidence is, it does not suggest that alcohol can help. Chronic alcoholism is a series of severe acute alcohol intoxications, anyway. That same study also does not support the idea that alcohol would repel parasites or make them less productive as in the fruit-fly and wasps study. I mean, it could - but where is the evidence? $\endgroup$ – Jan Dec 16 '19 at 12:47
  • $\begingroup$ This is a great well-cited answer. Just to add one more thing to discourage getting drunk to treat the parasite; a viable treatment is assessed via the risk-benefit ratio. Even if these studies were not present, becoming highly intoxicated may do as much damage to the host as the parasite you are trying to eradicate. According to the NHS, there is no safe level of alcohol consumption. $\endgroup$ – James Dec 16 '19 at 13:28
  • $\begingroup$ @user1136 You raise an important point that the PLOS study is limited in scope. And re the wasps, there is no doubt external use of alcohol can kill pathogens. This question addresses evidence surrounding ingested alcohol and if there are any associations with parasitic resistance or treatment. $\endgroup$ – James Dec 16 '19 at 13:31
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Although the previous answers give a resounding "No" for the case of human hosts and parasitic worms, a 2012 research paper (Alcohol Consumption As Self-Medication Against Blood-Borne Parasites In The Fruitfly) states that the larvae of Drosophila melanogaster (fruit flies) actively seek out foods containing ethanol when they are infected by the eggs/larvae of parasitic wasps.

(I don't know whether they do this when the parasite's egg has been laid inside them, or after it's hatched into a larva, or both.)

This paper was quoted by various popular science magazines of the time (see e.g. https://www.newscientist.com/article/dn21493-parasite-plagued-flies-self-medicate-on-booze/), and also metioned the use of ethanol as a preventative measure as well as a curative one.

Despite having evolved an increaed tolerance to the ethanol, however, the increased consumption may have some adverse side-effects on the infected fly larva.

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  • $\begingroup$ Generalising from alcohol to toxic substances in general - caterpillars of the Grammia incorrupta moth consume plants containing toxic pyrrolizidine alkaloids (PAs) to kill the eggs of parasitoids within them. The PAs are poisonous to the caterpillar as well as the parasites, and caterpillars that successfully exploit this strategy still suffer adverse health effects. web.archive.org/web/20160313220351/http://… $\endgroup$ – Astrid_Redfern Dec 15 '19 at 19:31
  • $\begingroup$ The New Scientist article you linked does not mention any use of alcohol for treatment of worms or other parasites in humans. $\endgroup$ – Jan Dec 16 '19 at 13:54
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The answer to your question depends on the kind of parasites you're focusing on.

Looking at bacteria and gastro-intestinal infections, I found three articles (one based on a model stomach, a second one based on a questionnaire and serum analysis and a third one describing a specific incident), which indicate that there is a certain protective effect of ethanol consumption.


This paper describes the effect of wine on Listeria innocua in a model stomach (I have only access to the abstract). Wine seems to have an antimicrobial effect, which can be traced back mainly to ethanol as well as to organic acids.

Ethanol exhibited a higher bactericidal effect than the mixture of the main wine organic acids. When testing the organic acids separately, malic and lactic acids were found to have the strongest effect. The combination of ethanol with the organic acids acted synergistically but to a lesser extent than wine itself.

If anyone has full access to this article it would be interesting to put it into perspective to point two of the (currently) accepted answer.


This paper, based on a questionnaire on dietary habits and serum analyses for for Helicobacter pylori immunoglobulin G antibodies (1'785 participants), comes to the conclusion that

[t]here was a clear inverse dose-response-relation between reported alcohol consumption and H. pylori infection.

[Also here, only the abstract is accessible.]


There is another paper describing the effect of alcohol consumption on a Salmonella outbreak in Spain. The sample size is relatively small (90 people), but the data suggests that

[t]here was a protective effect of alcohol that was stronger among the people who drank more than 40 gm of alcohol.

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  • $\begingroup$ Welcome to Biology.SE! Nice answer and a good job on providing supporting references. However, can you please include the complete reference information since links can break. Search on Google Scholar and click on the ‟ symbol to get reference information for journal articles. This is a good example of how to format references. Thanks! 😊 $\endgroup$ – tyersome Dec 14 '19 at 21:11
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    $\begingroup$ However, please note that the original question was about worms rather that bacteria. If you can't find a question for which this is a relevant answer on this site (I gave a quick look and didn't find any), I would suggest posting a relevant question and then move this answer to that question. $\endgroup$ – tyersome Dec 14 '19 at 21:24
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From the first principles:

The most sensitive to alcohol part of the human body is it's nervous system. Worms have much simpler (in both biochemistry and organization) nervous system, so they will probably suffer less from a generic poison that the alcohol is.

OTOH, you can easily find a substance that is WAY more toxic to the worms than to yourself. Up to and including being safe to be given to minors and reproducibly killing all the worms. Just ask the nearest pharmaceut.

p.s. in the same sense, alcohol is killing bacteries, but you cannot cure pneumonia by drinking, no matter what heavy drinkers assert.

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    $\begingroup$ +1 The key is finding something worse for parasites than for humans. Alcohol isn't likely to be the best candidate, and there is a whole sector of pharmaceutical industry devoted to optimising and producing alternative substances. $\endgroup$ – Pere Dec 15 '19 at 22:04

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