How Does DHM Work? GABA Receptors, Alcohol Enzymes and the Liver, Explained

Nobody knows exactly how DHM works in people: in rats, injected DHM blocked some of alcohol's effects on brain GABA-A receptors, and in mice, injected DHM sped up alcohol breakdown, but none of this has been confirmed in humans. So how does DHM work when you swallow it? A rat study giving DHM by mouth found no change in alcohol metabolism, and swallowed DHM is poorly absorbed, so the honest answer is that its mechanism in people is unknown.

Key takeaways

  • In a 2012 UCLA rat study, DHM injected at 1 mg/kg cut alcohol-induced loss of the righting reflex from about 113 to about 28 minutes without significantly changing blood alcohol.1
  • Injected DHM raised alcohol-processing enzymes (ADH1 and ALDH2) and lowered blood alcohol and acetaldehyde in mice, but DHM given by mouth to rats didn't change how fast alcohol was cleared.2, 3
  • Swallowed DHM is poorly absorbed: oral bioavailability was about 4% in rats, and blood exposure in mice was 7 to 24 times lower by mouth than by injection.4, 5
  • As of October 2026, no human study had measured DHM blood levels or tested any of these mechanisms in people; the first registered human absorption study had posted no results.6

How does DHM work? The main theories

There are two main theories, both from rodent and cell studies: DHM acts in the brain, at the GABA-A receptors alcohol also acts on, or in the liver, on the enzymes that break alcohol down. A third line looks at liver inflammation.

Some background helps. Your liver breaks alcohol down in two main steps: alcohol dehydrogenase (ADH) turns ethanol into acetaldehyde, a toxic compound, and aldehyde dehydrogenase (mainly ALDH2) turns acetaldehyde into acetate. CYP2E1 does more of the work after long-term heavy drinking.7 In the brain, alcohol boosts signaling through GABA-A receptors.1 For the full pathway, see how your body processes alcohol and what acetaldehyde is.

Does DHM affect GABA? The 2012 rat study

In rats, yes, when injected. In a 2012 UCLA study, DHM injected into the abdomen countered several of alcohol's effects, and the researchers traced that to GABA-A receptors.1

  • Intoxication. Rats given a large injected dose of alcohol (4 g/kg) lost their righting reflex, the ability to flip upright, for about 113 minutes. With 1 mg/kg of injected DHM, it was about 28 minutes.
  • Withdrawal-like behavior. Injected DHM reduced signs of alcohol tolerance, anxiety and seizure susceptibility in rats tested two days after a single large dose of alcohol.
  • Voluntary drinking. DHM mixed into the alcohol the rats drank (so taken by mouth) blunted the rise in how much alcohol they chose to drink.
  • In brain cells. DHM blocked alcohol's boost to GABA-A receptors. Flumazenil, which blocks the receptor's benzodiazepine site, also blocked DHM's effects.

For a walk-through of each experiment and its numbers, see the DHM rat studies.

Blood alcohol didn't change significantly, so DHM wasn't working by clearing alcohol faster.1 The limits are big: these were rats, DHM and alcohol were both injected into the abdomen (bypassing the gut), and the study measured intoxication, not hangover.

Later work muddied the picture. In a 2021 mouse study, injected DHM again shortened alcohol-induced loss of the righting reflex, but briefly; and in frog egg cells carrying one GABA-A receptor subtype, DHM increased receptor activity by 43%, while a DHM breakdown product decreased it.5

Could any of this explain next-day anxiety after drinking? No one has tested that: there are no human studies of DHM and hangxiety.

Does DHM speed up alcohol metabolism? The injected-mouse study vs. the oral-rat study

The two key studies disagree, and the one that used the route people actually use, by mouth, found no effect.

The two 2020 studies on DHM and alcohol metabolism, side by side
Silva et al. 2020 (University of Southern California)2 Skotnicová et al. 2020 (Charles University, Prague)3
Animals Mice on long-term forced alcohol drinking Rats
DHM route Injected into the abdomen By mouth (stomach tube), with the alcohol
DHM dose 5 and 10 mg/kg 10 mg/kg
Enzymes ADH1 and ALDH2 increased ADH activity and amount unchanged; ALDH not measured
Blood alcohol Blood alcohol and acetaldehyde fell after an alcohol dose No change in how fast alcohol was cleared, after single or repeated doses
Group size 6 to 10 mice per group (3 to 8 per measurement) 4 rats per group (2 in the repeated-dose test)
Authors' conclusion Authors say the findings "support the utility of DHM as a dietary supplement"; human benefit not shown "The proposed positive effect of DHM during alcohol intoxication has not been proven"

A 2026 systematic review called the overall findings on ethanol metabolism "inconsistent."8

In people, no study has tested DHM alone on blood alcohol or acetaldehyde. Hovenia drink trials found small, inconsistent differences, and in one, acetaldehyde was higher at 6 hours with the Hovenia drinks than with placebo.9 Your body clears alcohol at a fairly fixed pace, roughly one standard drink every one to two hours for many adults, and nothing has been shown to meaningfully speed that up.7, 10, 11

What did DHM studies find in the liver?

In mice fed alcohol, DHM fairly consistently reduced fat buildup, liver enzyme release and inflammation, whether injected or given by mouth. None of this has been tested in people who drink.

  • By mouth: 75 to 150 mg/kg a day for six weeks reduced liver injury, fat buildup and inflammation in mice on an alcohol diet, and changed CYP2E1 and the Nrf2 antioxidant pathway.12
  • Injected: 5 to 10 mg/kg reduced liver fat, liver enzymes, CYP2E1 and oxidative markers in mice.2
  • In rat liver cells: DHM lowered reactive oxygen species but only slightly improved cell survival after alcohol.3

The human DHM trials that measured liver markers were in people with fatty liver disease not caused by alcohol, at 300 to 600 mg a day.13, 14 They don't show that DHM protects anyone's liver from drinking. For alcohol-related liver disease, stopping drinking is the core of treatment.15

Why does absorption matter? The bioavailability problem

A mechanism only matters if enough DHM reaches the tissue, and swallowed DHM is poorly absorbed. In people, nobody has measured it yet.

  • Rats: after 20 mg/kg by mouth, blood DHM peaked at 21.6 ng/mL (about 0.07 µM) roughly 2.7 hours later, with a half-life of 3.7 hours. Absolute oral bioavailability was 4.02%.4
  • Mice: DHM by mouth gave 7.2 (females) to 23.8 (males) times less total blood exposure than the same dose injected.5
  • Why: DHM dissolves poorly in water and crosses the gut wall poorly, so researchers test special formulations to raise absorption in animals.8

For a rough sense of scale (our arithmetic, not a finding): the oral peak in rats, about 0.07 µM, is roughly one-fifteenth of the 1 µM concentration used in the 2012 brain-cell experiments.4, 1 Different species and tissues, so treat it as a sanity check, not a conclusion.

A Phase 1 study of purified DHM in 12 healthy volunteers (doses of 300 mg or 900 mg) was registered with an estimated September 2024 start; its last update listed it as not yet recruiting, and as of October 2026 it had posted no results.6

What does this mean for people, and what doesn't it mean?

DHM is a reasonable research target. That doesn't mean the effects seen in rodents happen in a person who swallows a capsule.

FTC guidance is blunt: animal and test-tube studies "aren't sufficient" to back health claims.16 No human study shows that DHM makes you less drunk, reduces blood alcohol, clears acetaldehyde faster or protects the liver of people who drink, or that more DHM does more.

For reference, After Party by Fuller Health is a single-ingredient DHM supplement: 650 mg of dihydromyricetin per capsule, 3,250 mg per 5-capsule serving, with nothing else but the cellulose capsule. (Fuller Health publishes this page and makes After Party.) After Party's 3,250 mg serving is higher than the doses used in published human DHM studies. Those studies gave up to about 970 mg a day, to people with fatty liver disease or type 2 diabetes, not to people who drink.17, 13, 14 Safety at 3,250 mg hasn't been studied. After Party will not prevent intoxication, lower your blood alcohol, or make it safe to drive. Its label facts are on the After Party facts page.

In test-tube studies with human liver enzymes, DHM inhibited CYP3A4, CYP2D6 and CYP2E1, enzymes that help clear many medications.18 That hasn't been tested in people, so ask a pharmacist or doctor first if you take prescription medicines. Combining DHM with sedatives or sleep medicines hasn't been studied either. Don't use DHM if you're pregnant or breastfeeding. More in Is DHM safe?

What questions are researchers still asking?

The big unknowns, as of October 2026:

  • How much DHM reaches human blood and brain after a capsule, and for how long?
  • Does DHM by mouth change blood alcohol or acetaldehyde in people?
  • Do DHM and its metabolites push GABA-A receptors in the same direction?
  • Do the liver findings in mice show up in people who drink, at any dose?
  • Is there a dose-response, and is high-dose or repeated use safe?
  • Does DHM interact with medicines or sedatives in people?

We log new studies in our DHM research tracker. For the basics, see what DHM is.

Frequently asked questions

Does DHM break down acetaldehyde?

Not directly: DHM isn't an enzyme. In one mouse study, injected DHM increased ALDH2, the enzyme that breaks down acetaldehyde, and blood acetaldehyde fell.2 A rat study giving DHM by mouth found no change in alcohol metabolism, and no study has measured acetaldehyde in people taking DHM alone.3

Does DHM affect GABA?

In rats and lab cells, yes. In a 2012 study, injected DHM blocked alcohol's boost to GABA-A receptors, apparently at the benzodiazepine site.1 A 2021 study complicated that picture, and none of it has been measured in people.5

Does DHM make you less drunk?

There's no human evidence that it does. Injected DHM reduced signs of intoxication in rats and mice, but that has never been shown in people taking it by mouth.1, 5 Don't drive after drinking, and don't drink more because you've taken a supplement.

Does DHM reduce blood alcohol levels?

Not in any human study of DHM alone. In animals the results conflict: injected DHM lowered blood alcohol in mice, while DHM by mouth didn't change it in rats.2, 3 Only time brings blood alcohol down.11

How long does DHM take to work?

No one knows: no effect has been shown in people, and there are no human absorption data. In rats, blood DHM peaked about 2.7 hours after an oral dose, with a half-life of about 3.7 hours.4 Animal timing doesn't translate directly to people.

Sources

  1. Shen Y, et al. Dihydromyricetin as a novel anti-alcohol intoxication medication. J Neurosci. 2012;32(1):390-401. PubMed
  2. Silva J, et al. Dihydromyricetin Protects the Liver via Changes in Lipid Metabolism and Enhanced Ethanol Metabolism. Alcohol Clin Exp Res. 2020;44(5):1046-1060. PubMed
  3. Skotnicová A, et al. Does dihydromyricetin impact on alcohol metabolism. Physiol Res. 2020;69(Suppl 4):S573-S581. PubMed
  4. Liu L, et al. Determination of dihydromyricetin in rat plasma by LC-MS/MS and its application to a pharmacokinetic study. Pharm Biol. 2017;55(1):657-662. PubMed
  5. Carry E, et al. Identification of Dihydromyricetin and Metabolites in Serum and Brain Associated with Acute Anti-Ethanol Intoxicating Effects in Mice. Int J Mol Sci. 2021;22(14):7460. PubMed
  6. University of Southern California. Phase I, Dose-Escalation Study of Dihydromyricetin (DHM) to Treat Alcohol-Associated Liver Disease (NCT05623501). ClinicalTrials.gov. Status unknown; no results posted as of October 9, 2026. ClinicalTrials.gov
  7. Cederbaum AI. Alcohol metabolism. Clin Liver Dis. 2012;16(4):667-85. PubMed
  8. Skinner SG, et al. Therapeutic Effects of Dihydromyricetin on Wholly Alcohol-Attributed Conditions: A Systematic Review. Nutrients. 2026;18(14):2221. PubMed
  9. Lee KW, et al. Clinical Evaluation of Hovenia dulcis Extract Combinations for Effective Hangover Relief in Humans. Foods. 2024;13(24):4021. PubMed
  10. National Institute on Alcohol Abuse and Alcoholism. What Is a Standard Drink? Updated December 2025. NIAAA
  11. National Institute on Alcohol Abuse and Alcoholism. Hangovers. Updated December 2025. NIAAA
  12. Qiu P, et al. Dihydromyricetin modulates p62 and autophagy crosstalk with the Keap-1/Nrf2 pathway to alleviate ethanol-induced hepatic injury. Toxicol Lett. 2017;274:31-41. PubMed
  13. Chen S, et al. Dihydromyricetin improves glucose and lipid metabolism and exerts anti-inflammatory effects in nonalcoholic fatty liver disease: A randomized controlled trial. Pharmacol Res. 2015;99:74-81. PubMed
  14. Michailidou E, et al. Dietary supplement based on dihydromyricetin in metabolic dysfunction-associated steatotic liver disease: a double-blind, placebo-controlled, randomized clinical trial. Ann Gastroenterol. 2026;39(1):54-62. PubMed
  15. Osna NA, et al. Alcoholic Liver Disease: Pathogenesis and Current Management. Alcohol Res. 2017;38(2):147-161. PubMed
  16. Federal Trade Commission. Health Products Compliance Guidance. December 2022. FTC
  17. Ran L, et al. Ampelopsis grossedentata supplementation effectively ameliorates the glycemic control in patients with type 2 diabetes mellitus. Eur J Clin Nutr. 2019;73(5):776-782. PubMed
  18. Liu L, et al. In vitro inhibitory effects of dihydromyricetin on human liver cytochrome P450 enzymes. Pharm Biol. 2017;55(1):1868-1874. PubMed
  19. National Institute on Alcohol Abuse and Alcoholism. Understanding the Dangers of Alcohol Overdose. Updated December 2025. NIAAA
  20. U.S. Department of Agriculture; U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. Released January 7, 2026. PDF
  21. Substance Abuse and Mental Health Services Administration. SAMHSA's National Helpline. SAMHSA
  22. MedlinePlus, U.S. National Library of Medicine. Alcohol withdrawal. Reviewed January 1, 2025. MedlinePlus

Published by Fuller Health, which makes After Party. This article is general information, not medical advice: talk to a doctor or pharmacist about your own health, medicines and drinking. Last reviewed October 9, 2026. How we research and write.

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