The best-known DHM rat study (UCLA, 2012) found that drunk rats given injected DHM got back on their feet in about a quarter of the time, and a 2020 mouse study found injected DHM raised liver enzymes that process alcohol and acetaldehyde. None of it has been shown in people: swallowed DHM is poorly absorbed, a rat study giving it by mouth found no drop in blood alcohol or acetaldehyde, and as of October 2026 no published randomized trial has tested DHM alone for hangover.
Key takeaways
- In the 2012 UCLA study, rats given a large injected dose of alcohol (4 g/kg) lay on their backs for about 113 minutes; with 1 mg/kg of injected DHM, about 28, with no significant change in blood alcohol.1
- In the same study, injected DHM blunted withdrawal signs in rats after a binge, and DHM mixed into their alcohol bottle kept intake from climbing (2.6 vs. 7.4 g/kg a day).1
- In mice, injected DHM raised the liver enzymes ADH1 and ALDH2, and serum alcohol and acetaldehyde were lower 45 minutes after alcohol and DHM injections.2
- By mouth, the evidence is weaker: rats given DHM by stomach tube cleared alcohol no faster, and in mice, swallowed DHM gave 7 to 24 times less blood exposure than injected DHM.3, 4
- As of October 2026, no published randomized trial had tested DHM alone for hangover in people.5
Why does the DHM story start with rats?
Because that's where the striking results are. Dihydromyricetin (DHM) is a plant flavonoid found in vine tea (Ampelopsis grossedentata) and, in much smaller amounts, in the Japanese raisin tree (Hovenia dulcis); see what DHM is. A 2026 review of DHM and alcohol counted 17 animal studies and 2 clinical ones, and both clinical studies used Hovenia extract, not DHM on its own.5
Animal experiments can push blood alcohol to dangerous levels and inject a compound to be sure it gets in, which makes them good at picking what deserves a human trial and poor at predicting what a capsule does. The UCLA team started from folk medicine: their paper notes that Hovenia "is listed among the premier anti-hangover herbal medicines in China's first pharmacopoeia."1 Tradition isn't evidence. It's a reason to look.
What is the righting reflex test, and what did DHM do?
It's a stopwatch test of how drunk a rat is. In the 2012 UCLA study, injected DHM cut the time heavily dosed rats spent unable to turn over by about three-quarters.1
Put a rat on its back and it rolls onto its feet: that's the righting reflex. Enough alcohol takes it away. The researchers injected male rats with alcohol into the abdomen, laid each on its back in a V-shaped support and timed how long it took until the rat could "flip over three times in 30 s."1
The doses were heavy. At 3 g of alcohol per kilogram, plasma alcohol 30 minutes in averaged about 335 mg/dL, roughly four times the 0.08% (80 mg/dL) level that defines binge drinking in people (our arithmetic; rat plasma vs. a human blood threshold).1, 6 Here's what injected DHM did (4 to 13 rats per group):1
- At 4 g/kg of alcohol: 112.8 minutes on their backs; with 1 mg/kg of DHM, 28.2.
- At 3 g/kg, with 3 mg/kg of DHM: 2.7 minutes, versus 69.0 for alcohol alone.
- Timing: given 30 minutes after the alcohol, to rats already down, DHM cut the remaining time to 19 minutes, versus 42 with saline.
- DHM alone: nothing at 1 mg/kg, but 100 and 300 mg/kg of DHM by itself put rats down for about 3 and 10 minutes.
Did DHM just clear the alcohol faster?
Not at the main dose. In rats injected with 3 g/kg, plasma alcohol 30 minutes in was 335 mg/dL without DHM and 288 with 1 mg/kg, not a statistically significant difference (3 to 4 rats per group); 10 mg/kg lowered it significantly at 30 minutes only. At 4 g/kg, there was no significant effect. The authors concluded the change in alcohol levels was "not sufficient to account for" the faster recovery.1
They pointed to GABA-A receptors, the brain's main braking system, which alcohol boosts. In rat brain slices, DHM blocked that boost, yet on its own it enhanced the receptors, which fits the high-dose sedation. In live rats, flumazenil, which blocks the benzodiazepine site on those receptors, undid injected DHM's effect: 56 minutes down instead of 2.7.1 More in how DHM is thought to work.
What else did the UCLA team test?
Withdrawal and drinking. For the withdrawal tests, rats got a single injected binge (3 g/kg), with or without 1 mg/kg of injected DHM, and were tested 48 hours later.1
- Tolerance. A new dose of alcohol knocked binged rats down for only 10.8 minutes, versus 63.6 in rats that skipped the binge. Rats that had DHM with their binge stayed down 61.0 minutes, like controls (5 per group).
- Anxiety. The elevated plus maze is a raised, plus-shaped platform with two walled arms and two open ones; anxious rats avoid the open arms. Controls spent 57% of a 5-minute session in the open arms. Rats in withdrawal spent significantly less; rats that had DHM split their time like controls.
- Seizures. After the seizure-inducing drug pentylenetetrazol, seizures lasted 6.5 minutes in rats in withdrawal, 1.7 with DHM and 0.9 in controls (6 to 13 per group).
Did DHM change how much the rats chose to drink?
Here the DHM went in by mouth. Rats had a bottle of 20% alcohol beside their water for 24 hours at a time, three days a week, a schedule designed to make intake escalate. On plain alcohol, intake roughly doubled within weeks, from 3.9 to 7.4 g/kg a day. Rats whose alcohol bottle also contained DHM (0.05 mg/mL) were at 2.6. When half the plain-alcohol rats had DHM added in week 7, their intake fell to 1.2 by the end of week 8 (6 to 8 per group). A taste test of DHM in plain water showed no aversion.1
In mice, though, 10 mg/kg of DHM injected on its own didn't reduce drinking in a 2021 two-bottle study.7 Different species, route and setup, but the finding hasn't held up in every model.
What did the liver and enzyme studies find?
In mice, injected DHM reduced alcohol-related liver fat and raised the liver's alcohol-processing enzymes. DHM given to mice in their diet produced a messier picture.2, 9
In the 2020 University of Southern California study, male mice were kept on alcohol for 8 weeks and given DHM injections (5 or 10 mg/kg). They had less liver fat, lower liver triglycerides, and ALT and AST levels close to those of mice that never drank (6 per group for most measures).2
The liver clears most alcohol in two steps: ADH turns it into acetaldehyde, a toxic compound, and ALDH2 turns acetaldehyde into acetate (see what acetaldehyde is). Liver protein blots from the DHM mice showed more ADH1 and ALDH2. Mice injected with alcohol (3.5 g/kg) plus DHM had lower serum alcohol and acetaldehyde 45 minutes later than mice given alcohol alone (6 per group).2 So the study didn't show DHM breaking acetaldehyde down. It showed more of the enzyme that does, with DHM injected.
A 2023 study from the same group mixed DHM into an alcohol liquid diet (6 mg/mL) for female mice. ALT, AST, blood triglycerides and inflammatory markers fell. But liver triglycerides rose and liver fat droplets were larger (9.9 vs. 7.4 square micrometers with alcohol alone), which the authors read as safer fat storage. They call it a "proof-of-concept study," and several assays used 3 or 4 mice.9
Which DHM studies found nothing?
The most direct oral test found no effect on alcohol clearance, and other results point the same way.
At Charles University in Prague, researchers gave fasted male rats 40% alcohol by stomach tube, with or without 10 mg/kg of DHM, and measured blood samples at 5, 15, 30 and 60 minutes by gas chromatography. DHM made no significant difference to alcohol or acetaldehyde. After a second dose of alcohol the next day, blood alcohol was "markedly higher" in the rats that had DHM. Nor did DHM change ADH activity in rat liver cells.3 The verdict: "the proposed positive effect of DHM during alcohol intoxication has not been proven." With 4 rats per group (then 2) and no ALDH measurement, the study can't settle the question, but it used the oral route.3
- Plain DHM by mouth: in two studies of reformulated DHM (one in mice; the other's abstract says only "drunk animals"), ordinary DHM had little or no effect on blood alcohol.10, 11, 5
- The review: findings on alcohol metabolism and behavior were "inconsistent," and "several studies reporting limited effects of native DHM used oral administration."5
Injected vs. swallowed: why does the route matter?
Because swallowed DHM barely gets in. Nearly every striking result used DHM injected into the abdominal cavity (an intraperitoneal, or i.p., injection), which doesn't rely on absorption from the gut. In rats, about 4% of a swallowed dose reaches the bloodstream.5 In a 2021 mouse study, the same 50 mg/kg dose gave 7 to 24 times more DHM in the blood injected than swallowed.4
The effect was also brief. Mice given alcohol by stomach tube (5 g/kg) regained their righting reflex sooner after injected DHM, but the effect depended on timing and sex, and DHM was detectable in the brain at 15 minutes but not at 45. The authors cite "poor absorption and rapid clearance."4
The UCLA paper says DHM "acts equally well orally (gavage)," but the gavage test behind that line measured brain-slice activity two days after rats got alcohol and DHM by stomach tube, not behavior.1 And don't turn rat doses into pill counts; for what's known about human doses, see DHM dosage and timing.
Was there a water or swim test?
Not in the alcohol research, as far as we can find. We searched PubMed for DHM (also called ampelopsin) with swimming, forced-swim and water-maze tests, and none of the results involved alcohol.12 Water tests do appear elsewhere in DHM research. In a 2022 depression-model study, mice given a stress hormone for 23 days spent less time floating still in a 6-minute forced-swim test if they also got 20 mg/kg of injected DHM.13 Water-maze memory tests, in which a rodent swims to a hidden platform, appear in DHM studies of aging, Alzheimer's and epilepsy models.12 None involve drinking.
Summary table of the key DHM animal studies
| Study | Animal | DHM dose and route | Test | Result | Caveat |
|---|---|---|---|---|---|
| Shen 2012 (UCLA)1 | Male rats | 1 or 3 mg/kg, injected; alcohol injected | Righting reflex | 112.8 to 28.2 min (4 g/kg alcohol, 1 mg/kg DHM); 69.0 to 2.7 min (3 g/kg, 3 mg/kg) | Blood alcohol not significantly changed at 1 mg/kg; 4 to 13 per group |
| Shen 2012 | Male rats | 1 mg/kg, injected with a binge | Withdrawal at 48 h | No tolerance; seizures 1.7 vs. 6.5 min; open-arm time like controls | One binge; 5 to 13 per group |
| Shen 2012 | Male rats | 0.05 mg/mL in the alcohol bottle (by mouth) | Two-bottle drinking | 2.6 vs. 7.4 g/kg a day | 6 to 8 per group |
| Carry 20214 | Mice | 50 mg/kg injected; alcohol by stomach tube | Righting reflex; blood and brain DHM | Shorter loss of righting; DHM gone from brain by 45 min | Short-lived; 7 to 24 times less exposure by mouth |
| Silva 2020 (USC)2 | Male mice | 5 or 10 mg/kg, injected | 8 weeks of alcohol; one 3.5 g/kg alcohol injection | Less liver fat; more ADH1 and ALDH2; serum alcohol and acetaldehyde down | Injected; 3 to 8 per measure |
| Janilkarn-Urena 2023 (USC)9 | Female mice | 6 mg/mL in the diet (by mouth) | 5-week alcohol diet | ALT, AST, blood triglycerides, inflammation down | Liver triglycerides rose; 3 to 4 per assay |
| Skotnicová 2020 (Prague)3 | Male rats | 10 mg/kg by stomach tube, with the alcohol | Blood alcohol and acetaldehyde | No significant change | 2 to 4 per group; ALDH not measured |
| Silva 2021 (USC)7 | Mice | 10 mg/kg, injected | Two-bottle drinking | No drop in drinking with DHM alone | Mainly an ivermectin study |
| Dong 202310, 5 | Male mice | Plain vs. reformulated DHM, by mouth | Righting reflex; blood alcohol | Plain DHM didn't significantly change blood alcohol; the reformulated version did | Formulation study |
For every DHM study by date, human trials included, see our DHM research tracker.
What do the DHM rat studies mean for people?
They're the reason DHM deserves human trials, not proof that it does anything for people. But injected results in rats aren't results in people, swallowed DHM is poorly absorbed,5, 4 and three more gaps stand in the way:
- Alcohol: the rats were at roughly four times the human binge threshold, a model of severe intoxication, not a night out.1, 6
- Outcomes: intoxication, withdrawal, drinking and liver markers. None of these studies measured a hangover, which has its own mix of causes.
- Replication: when a rat study gave DHM by mouth, blood alcohol and acetaldehyde didn't fall as they had in the injected mouse study.3, 2
A note on our interest: Fuller Health sells a DHM supplement. That's one reason this page puts the null results next to the striking ones.
What we don't know yet
- Hangover in people: as of October 2026, no published randomized trial had tested DHM alone for hangover.5
- Absorption in people: a Phase 1 study of purified DHM in 12 healthy volunteers is registered at the University of Southern California. Its last known status is "not yet recruiting," and no results are posted.14
- Alcohol and acetaldehyde in people: untested, and the animal data conflict.2, 3
- Safety at the doses people take: see is DHM safe?
What would settle it: a placebo-controlled trial of DHM alone in healthy adults who drink, measuring blood DHM, alcohol, acetaldehyde and hangover symptoms.
Frequently asked questions
What did the UCLA DHM rat study find?
Rats given a large injected dose of alcohol plus 1 mg/kg of injected DHM lost their righting reflex for about 28 minutes instead of about 113, with no significant change in blood alcohol. Injected DHM also blunted withdrawal signs, and DHM in the rats' alcohol bottle kept their drinking from escalating. The 2012 study didn't test hangover or people.1
What is the righting reflex test?
A standard rodent measure of intoxication: the animal is laid on its back and timed until it can turn over. In the UCLA study, the reflex counted as back when a rat could flip over three times in 30 seconds.1
Does DHM break down acetaldehyde?
Not that any study has shown. In mice, injected DHM increased the liver enzymes ADH1 and ALDH2, and ALDH2 is what breaks acetaldehyde down; serum acetaldehyde was lower 45 minutes after alcohol and DHM injections. A rat study giving DHM by mouth found no change in blood alcohol or acetaldehyde, and none of this has been tested in people.2, 3
Was the DHM in the rat studies swallowed or injected?
Mostly injected. In the UCLA study, only the drinking experiment and a brain-cell test gave DHM by mouth; the Prague rat study used a stomach tube. Swallowed DHM is poorly absorbed: about 4% in rats.1, 3, 5
Sources
- Shen Y, et al. Dihydromyricetin as a novel anti-alcohol intoxication medication. J Neurosci. 2012;32(1):390-401. PMID 22219299. J Neurosci (full text)
- 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. PMID 32267550. PubMed
- Skotnicová A, et al. Does dihydromyricetin impact on alcohol metabolism. Physiol Res. 2020;69(Suppl 4):S573-S581. PMID 33656905. Full text (PDF)
- 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. PMID 34299083. Full text
- Skinner SG, et al. Therapeutic Effects of Dihydromyricetin on Wholly Alcohol-Attributed Conditions: A Systematic Review. Nutrients. 2026;18(14):2221. PMID 42514290. Full text
- NIAAA. Understanding the Dangers of Alcohol Overdose. Updated December 2025. NIAAA
- Silva J, et al. A Novel Dual Drug Approach That Combines Ivermectin and Dihydromyricetin (DHM) to Reduce Alcohol Drinking and Preference in Mice. Molecules. 2021;26(6):1791. PMID 33810134. Full text
- SAMHSA. SAMHSA's National Helpline. SAMHSA
- Janilkarn-Urena I, et al. Dihydromyricetin supplementation improves ethanol-induced lipid accumulation and inflammation. Front Nutr. 2023;10:1201007. PMID 37680900. Full text
- Dong J, et al. Preparation of Dihydromyricetin-Loaded Self-Emulsifying Drug Delivery System and Its Anti-Alcoholism Effect. Pharmaceutics. 2023;15(9):2296. PMID 37765265. Full text
- Ye J, et al. Self-Assembled Micelles Improve the Oral Bioavailability of Dihydromyricetin and Anti-Acute Alcoholism Activity. AAPS PharmSciTech. 2021;22(3):111. PMID 33748928. Springer
- PubMed search: dihydromyricetin "water maze". 7 results, none involving alcohol. Searched October 9, 2026. PubMed search
- Huang J, et al. Dihydromyricetin Attenuates Depressive-like Behaviors in Mice by Inhibiting the AGE-RAGE Signaling Pathway. Cells. 2022;11(23):3730. Full text
- University of Southern California. Phase I, Dose-Escalation Study of Dihydromyricetin (DHM) to Treat Alcohol-Associated Liver Disease (NCT05623501). ClinicalTrials.gov. No results posted as of October 9, 2026. ClinicalTrials.gov
- USDA; HHS. Dietary Guidelines for Americans, 2025-2030. January 2026. PDF
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.