DHM appeared well tolerated in the few small human studies so far, at 300 to 970 mg a day, but long-term safety, high doses and drug interactions haven't been studied in people, so ask a clinician before using it. So is DHM safe? Reasonably reassuring at studied doses, unknown beyond them. Don't use it if you're pregnant or breastfeeding, and ask a pharmacist first if you take prescription medicines.
Key takeaways
- NIH's LiverTox lists no case reports of clinically apparent liver injury from DHM and rates it an unlikely cause (likelihood score E), but notes there have been few prospective safety trials.1
- Three randomized DHM trials enrolled 195 adults with fatty liver disease or type 2 diabetes, at 300 to 970 mg a day for 1 to 12 months, and reported no major safety problems, though side-effect reporting was sparse.2, 3, 4
- In test-tube studies, DHM inhibited three drug-processing enzymes, CYP3A4, CYP2D6 and CYP2E1; no human interaction study exists.5
- DHM hasn't been studied in pregnancy or breastfeeding, and the proposed use of a Hovenia extract that EU regulators reviewed in 2020 excluded pregnant and breastfeeding women.6
- One serving of After Party by Fuller Health (3,250 mg of DHM) is about 3.4 times the highest daily DHM dose with published human data (970 mg), and safety at that dose hasn't been studied.3
Is DHM safe? The short answer
At the doses studied so far, DHM has a reassuring but thin record. Beyond those doses, and over the long term, nobody knows.
What's reassuring: no case reports of liver injury from DHM in NIH's LiverTox, and no major problems in three small trials.1 What's missing: long-term, high-dose and drug-interaction studies, and any data in pregnancy. Being on sale isn't proof of safety, either: FDA says it can't approve dietary supplements before they're sold.7
What do human studies report about DHM safety?
Little that's alarming, and little detail. The trials were small, short and designed to measure lab markers, not side effects.
| Study | Who | DHM dose | Length | Safety reporting |
|---|---|---|---|---|
| Chen et al. 20152 | 60 adults with fatty liver disease | 300 or 600 mg a day | 3 months | No adverse events in either group, per LiverTox.1 |
| Ran et al. 20193 | 80 adults with type 2 diabetes (70 finished) | 970 mg a day, in vine tea | 1 month | The abstract doesn't describe side effects. |
| Michailidou et al. 20264 | 55 adults with fatty liver disease | 300 mg a day, plus vitamins C and E and choline | 12 months | 9 withdrew "for personal reasons" (2 vs. 7 on placebo). The abstract doesn't describe side effects. |
| For comparison: one After Party serving | Not studied | 3,250 mg | Not studied | No human safety data at this dose. |
We didn't have every full text, so there may be adverse-event details we haven't seen.
Animal safety data are thin too. We found no published 90-day toxicity study of purified DHM; a 28-day rat study of a herbal mixture that was 36% DHM found no signs of toxicity.8
After Party 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.3, 2, 4 Safety at 3,250 mg hasn't been studied. See DHM dosage and timing and the After Party facts page.
What are the possible side effects of DHM?
No consistent side effects have been documented in people, mostly because so few have been studied. That's an absence of evidence, not proof of no risk.
- Liver. LiverTox says DHM "has not been linked to serum enzyme elevations during therapy."1 Hovenia, a different plant that contains a little DHM, has been linked to three cases of toxic hepatitis in Korea.9
- Drowsiness. In rodents, DHM acts at the benzodiazepine site of GABA-A receptors.10 Whether that makes people drowsy is unknown; a 288-person trial of DHM for sleep problems finished in 2022 but hasn't been published.11
- Warning signs with any supplement. FDA's examples of possible reactions include rash or hives, severe or persistent nausea, vomiting or abdominal pain, dark urine, yellowing of the skin or eyes, abnormal bleeding, and throat, lip or tongue swelling. If you notice any of these, stop the supplement and get medical advice.7
Can DHM interact with medications or liver enzymes?
Possibly. Lab studies show it can inhibit some drug-processing enzymes, but no human interaction study exists.
- Human liver enzymes in a test tube: DHM inhibited CYP3A4, CYP2E1 and CYP2D6, but not five other CYP enzymes.5 A 2024 study found only minor effects on CYP3A4, so the results conflict.12
- Rats (route not given in the abstracts): DHM raised blood exposure to the drug triptolide by 98% after one dose but didn't change fluconazole levels.13, 14
- Sedatives: DHM acts at a benzodiazepine-related site in rodents; combinations with sedatives or sleep medicines haven't been studied in people.10
Our reading, and it's an inference: in rats, blood DHM after an oral dose (about 0.07 µM) was at least 200 times lower than the concentrations that inhibited these enzymes in the test tube, which suggests low risk at typical doses.15, 5 But human blood levels are unknown, gut-wall levels may be higher, and nobody has tested 3,250 mg. If you take prescription medicines or sedatives, ask a pharmacist or doctor first.
Who should avoid DHM or ask a clinician first?
- Anyone pregnant or breastfeeding: don't use it. There are no human data, and the proposed use of a Hovenia extract that EU regulators reviewed in 2020 excluded pregnant and breastfeeding women.6 US guidelines also say pregnant women should avoid alcohol completely.16
- People with liver disease. The fatty liver trials used 300 to 600 mg a day; there are no data at higher doses or in other liver diseases. That Hovenia extract's proposed use also excluded people with chronic disease such as liver problems.6 Ask your doctor.
- People with kidney disease, and older adults. Not studied.
- Anyone under 21. DHM products marketed around drinking are for adults only.
Is DHM a safety net for drinking?
No. Nothing in the DHM research shows it makes drinking safer for people. In news coverage of FDA's 2020 warning letters to seven hangover-product companies, the then-head of FDA's dietary supplement office was quoted as saying that "dietary supplements are not a substitute for responsibly limiting one's alcohol consumption."17, 18
There's no human evidence that DHM reduces blood alcohol, intoxication or alcohol's harm to the liver. After Party will not prevent intoxication, lower your blood alcohol, or make it safe to drive. For practical limits, see how to drink responsibly.
Why does testing matter for DHM quality and contamination?
Because FDA doesn't check supplements before sale, and some labels don't even say how much DHM they contain.7, 23 A certificate of analysis (COA), a lab report on one batch, is the best check you have: look for DHM content, heavy metals, microbes and the lab's name.
As an example, the published COA for After Party's lot 1032 (manufactured June 2023) reports 3,250 mg of DHM per serving against a specification of at least 3,250 mg. It reports heavy metals within limits by the USP <233> method, and total plate count, yeast and mold, Salmonella and E. coli within limits.24 The COA doesn't name the testing lab. More in how After Party is sourced and tested.
How do you report a side effect to FDA?
Stop taking the supplement, get medical care if you need it (call 911 for severe symptoms), and report it to FDA, even if you're not sure the supplement was the cause.7
- Online: FDA's Safety Reporting Portal, safetyreporting.hhs.gov.
- By phone: through an FDA Consumer Complaint Coordinator. FDA's SAFEFOOD line, 1-888-SAFEFOOD (1-888-723-3366), can give you the number for your area.
- Tell the maker too. For After Party, reach Fuller Health through our contact page.
What we don't know yet about DHM safety
- Whether DHM is safe above about 1 gram a day, including at 3,250 mg.
- Whether it's safe for longer than 12 months.
- Whether it interacts with medicines, sedatives or alcohol in people.
- How it affects pregnancy, breastfeeding, liver or kidney disease, and older adults.
See also can you take DHM every day?, our DHM research tracker and what DHM is.
Frequently asked questions
Does DHM have side effects?
No consistent side effects have been documented, but fewer than 200 people have taken part in randomized DHM trials, and only some of them got DHM.2, 3, 4 That's too few to rule out uncommon problems. If you notice anything unusual, stop and talk to a doctor.
Can DHM hurt your liver?
NIH's LiverTox lists no case reports of clinically apparent liver injury from DHM and rates it an unlikely cause, but there have been few safety trials.1 Hovenia, a different plant that contains DHM, has been linked to rare cases of toxic hepatitis.9 If you have liver disease, ask your doctor first.
Can I take DHM with medication?
Ask a pharmacist first. In lab studies DHM inhibited CYP3A4, CYP2D6 and CYP2E1, enzymes that process many medicines, though this hasn't been tested in people.5 Be especially careful with sedatives or sleep medicines, which haven't been studied with DHM.
Sources
- National Institute of Diabetes and Digestive and Kidney Diseases. LiverTox: Dihydromyricetin. NCBI Bookshelf. Last updated August 16, 2023. NCBI Bookshelf
- 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
- 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
- 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
- Liu L, et al. In vitro inhibitory effects of dihydromyricetin on human liver cytochrome P450 enzymes. Pharm Biol. 2017;55(1):1868-1874. PubMed
- Turck D, et al. Safety of hot water extract of fruits and peduncles of Hovenia dulcis as a novel food pursuant to Regulation 1(EU) 2015/2283. EFSA J. 2020;18(8):e06196. PubMed
- U.S. Food and Drug Administration. Dietary Supplements: Report Adverse Events to FDA (consumer fact sheet). May 2022. FDA (PDF)
- Chien MY, et al. Dihydromyricetin-rich herbal mixture extracts as a potential prescription for treatment of metabolic syndrome in rats fed a high-fat diet and subacute toxicity assessment in rats. J Tradit Complement Med. 2019;9(3):221-226. PubMed
- Sferrazza G, et al. Hovenia dulcis Thumberg: Phytochemistry, Pharmacology, Toxicology and Regulatory Framework for Its Use in the European Union. Molecules. 2021;26(4):903. PubMed
- Shen Y, et al. Dihydromyricetin as a novel anti-alcohol intoxication medication. J Neurosci. 2012;32(1):390-401. PubMed
- University of Southern California. Stress-, Anxiety-, and Cellphone Use-induced Sleep Deficits and a Potential Complementary Therapy (NCT05280561). ClinicalTrials.gov. Completed in 2022; no publication found as of October 9, 2026. ClinicalTrials.gov
- Dombi Á, et al. Interaction of myricetin, ampelopsin (dihydromyricetin), and their sulfate metabolites with serum albumin, cytochrome P450 (CYP2C9, 2C19, and 3A4) enzymes, and organic anion-transporting polypeptides (OATP1B1 and OATP2B1). Pharmacol Res Perspect. 2024;12(5):e70021. PubMed
- Deng Y, et al. Dihydromyricetin affect the pharmacokinetics of triptolide in rats. Xenobiotica. 2020;50(3):332-338. PubMed
- Liu H, et al. The Effect of Dihydromyricetin on the Pharmacokinetics of Fluconazole in Sprague-Dawley Rat Plasma, Based on High-Performance Liquid Chromatography-Tandem Mass Spectrometry. Drug Des Devel Ther. 2023;17:2657-2667. PubMed
- 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
- U.S. Department of Agriculture; U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. Released January 7, 2026. PDF
- Food Manufacturing. FDA Warns 7 Companies About Illegally Selling Hangover Cures. July 30, 2020. Food Manufacturing
- Cleveland Clinic Health Essentials. Hangover Pills Aren't Worth the Hype. March 13, 2024. Cleveland Clinic
- National Institute on Alcohol Abuse and Alcoholism. Understanding the Dangers of Alcohol Overdose. Updated December 2025. NIAAA
- National Institute on Alcohol Abuse and Alcoholism. Hangovers. Updated December 2025. NIAAA
- Substance Abuse and Mental Health Services Administration. SAMHSA's National Helpline. SAMHSA
- MedlinePlus, U.S. National Library of Medicine. Alcohol withdrawal. Reviewed January 1, 2025. MedlinePlus
- Verster JC, et al. Unknown safety and efficacy of alcohol hangover treatments puts consumers at risk. Addict Behav. 2021;122:107029. PubMed
- Fuller Health. After Party certificate of analysis, lot 1032 (manufactured June 2023). Testing laboratory not named on the document. 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.