Ginger

In Chinese medicine fresh and dried ginger are treated as distinct remedies. Dried ginger (gan jiang) is pungent and hot, entering the Spleen, Kidney, Lung and Heart channels. It warms the middle jiao, rescues “devastated yang,” warms the lungs and channels, moves fluid retention and stops bleeding. It is given for spleen-and-stomach deficiency-cold patterns with cold abdominal pain, vomiting and diarrhoea ^{34,35Reference 34Teeguarden · 2000The Ancient Wisdom of the Chinese Tonic HerbsReference 35Yang et al. · 2013Introduction to Chinese Materia Medica (3rd ed.), pp}.

It’s often added to tonic formulas to magnify the warming, Qi-tonifying action of the other herbs ^{34Reference 34Teeguarden · 2000The Ancient Wisdom of the Chinese Tonic Herbs}.

Classical practice uses it cautiously — no more than 2 g/day — in pregnancy, and avoids it in blood-heat or yin-deficiency patterns showing a red tongue with scanty coating and dry stool ^{35,36Reference 35Yang et al. · 2013Introduction to Chinese Materia Medica (3rd ed.), ppReference 36Bone · 2003A Clinical Guide to Blending Liquid Herbs: Herbal Formulations for the Individual Patient}.

Fresh ginger (sheng jiang) is pungent and warm. It disperses the exterior and dissipates cold, warms the centre, stops vomiting, dissolves phlegm and resolves toxins ^{34,35Reference 34Teeguarden · 2000The Ancient Wisdom of the Chinese Tonic HerbsReference 35Yang et al. · 2013Introduction to Chinese Materia Medica (3rd ed.), pp}.

It’s the form reached for in wind-cold exterior patterns and for vomiting (typically with a white, glossy tongue coating), and is contraindicated where there is a dry red tongue with thirst and aversion to heat ^{35Reference 35Yang et al. · 2013Introduction to Chinese Materia Medica (3rd ed.), pp}. Fresh ginger is added late to a decoction rather than simmered with the rest of the formula, because its volatile oil is driven off by prolonged heat ^{39Reference 39Lai W et al et al. · 2022Systematic reviewZingiber officinale: a systematic review of botany, phytochemistry and pharmacology of gut microbiota-related gastrointestinal benefits — systematic reviewView study →}.

Ayurveda uses the same rhizome and draws the same fresh/dried line. Dried ginger is a near-ubiquitous component of digestive and carminative formulae rather than a herb reached for on its own ^{38Reference 38Ali BH et al. · 2008ReviewSome phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): a review of recent research — reviewView study →}.

It is classed and used as a warming digestive — the remedy given for indigestion and vomiting, for constipation, and for the rheumatic and arthritic complaints and inflammatory, febrile conditions that Ayurvedic practice reads as cold or sluggish ^{38Reference 38Ali BH et al. · 2008ReviewSome phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): a review of recent research — reviewView study →}.

The Ayurvedic Pharmacopoeia of India records the dried rhizome as pungent (katu) in taste, light and unctuous, heating in potency and sweet after digestion — the unusual post-digestive turn that lets it warm without drying — pacifying vata and kapha. It lists the powder for weak digestion (agnimandya), abdominal distension, rheumatism (amavata), breathlessness and anaemia at 1–2 g ^{52Reference 52Government of India et al.ReviewThe Ayurvedic Pharmacopoeia of India, Part I, Vol}.

In Unani (Tibb-Unani) practice, ginger is given for arthritis, sprains and muscular aches, sore throat, cramps, indigestion and fever ^{38Reference 38Ali BH et al. · 2008ReviewSome phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): a review of recent research — reviewView study →}.

Western herbalism classes ginger as a warming aromatic and gives it three jobs. It is first a carminative and digestive stimulant for dyspepsia, flatulence and colic; the pungent aromatics of that class have been used for functional dyspeptic complaints since antiquity ^{40Reference 40Saller R et al. · 2001ReviewDyspeptic pain and phytotherapy: a review of traditional and modern herbal drugs — reviewView study →}.

It is second a diaphoretic, taken hot in feverish colds to bring on a sweat. It is third, applied to the skin, a rubefacient for muscular and rheumatic pain ^{38Reference 38Ali BH et al. · 2008ReviewSome phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): a review of recent research — reviewView study →}.

Both forms are used. Fresh ginger and its juice are traditionally preferred at the onset of a cold, and the dried rhizome is regarded as the more warming, favoured for internal cold and sluggish digestion.

It is given as a tea or decoction, as a tincture or liquid extract, and as a small warming addition to a formula, included to drive the circulation of the other herbs.

In the European Union, ginger is accepted as a traditional herbal medicine for motion sickness, mild spasmodic digestive complaints with bloating and flatulence, temporary loss of appetite, minor joint pain and the symptoms of the common cold ^{53Reference 53Committee on Herbal Medicinal Products · 2025ReviewEuropean Union herbal monograph on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory monographView study →}.

A meta-analysis of 12 RCTs (1,278 pregnant women) found ginger significantly improved nausea versus placebo (mean difference 1.20, 95% CI 0.56–1.84). The reduction in vomiting episodes only trended toward significance (MD 0.72, 95% CI −0.03 to 1.46) ^{1Reference 1Viljoen E et al et al. · 2014Meta-analysisA systematic review and meta-analysis of the effect and safety of ginger in the treatment of pregnancy-associated nausea and vomiting — meta-analysisView study →}.

The same review found no significant rise in miscarriage compared with placebo or vitamin B6, and no more heartburn or drowsiness ^{1Reference 1Viljoen E et al et al. · 2014Meta-analysisA systematic review and meta-analysis of the effect and safety of ginger in the treatment of pregnancy-associated nausea and vomiting — meta-analysisView study →}. Subgroup analysis favoured daily doses below 1,500 mg for nausea ^{1Reference 1Viljoen E et al et al. · 2014Meta-analysisA systematic review and meta-analysis of the effect and safety of ginger in the treatment of pregnancy-associated nausea and vomiting — meta-analysisView study →}.

A second meta-analysis of 6 trials (508 women) found that about 1 g a day for at least 4 days was associated with a five-fold likelihood of improvement ^{2Reference 2Thomson M et al et al. · 2014Meta-analysisEffects of ginger for nausea and vomiting in early pregnancy: a meta-analysis — meta-analysisView study →}.

The Cochrane review of interventions for early-pregnancy nausea rates the ginger evidence as limited and inconsistent in quality ^{3Reference 3Matthews A et al et al. · 2015Systematic reviewInterventions for nausea and vomiting in early pregnancy — systematic review (Cochrane)View study →}.

Gap: trials use powdered or capsule ginger, not the 1:2 liquid extract, and the effect on vomiting is weaker than on nausea.

A 2024 meta-analysis of 12 trials found ginger more effective than placebo for both pain intensity (SMD −1.13, 95% CI −1.59 to −0.68) and pain duration. It found no difference between ginger and NSAIDs for pain intensity (SMD 0.01, 95% CI −0.24 to 0.25) ^{4Reference 4Moshfeghinia R et al et al. · 2024Meta-analysisGinger for pain management in primary dysmenorrhea: a systematic review and meta-analysis — meta-analysisView study →}.

An earlier meta-analysis of four placebo-controlled trials reported a similarly large reduction in the pain visual-analogue score ^{5Reference 5Daily JW et al et al. · 2015Meta-analysisEfficacy of ginger for alleviating the symptoms of primary dysmenorrhea: a systematic review and meta-analysis of randomized clinical trials — meta-analysisView study →}. Effective regimens used 750–2,000 mg/day of powder over the first three to four days of the period ^{5Reference 5Daily JW et al et al. · 2015Meta-analysisEfficacy of ginger for alleviating the symptoms of primary dysmenorrhea: a systematic review and meta-analysis of randomized clinical trials — meta-analysisView study →}.

Gap: the trials are small, carry risk of bias, and rarely report safety data ^{4Reference 4Moshfeghinia R et al et al. · 2024Meta-analysisGinger for pain management in primary dysmenorrhea: a systematic review and meta-analysis — meta-analysisView study →}.

A meta-analysis of placebo-controlled RCTs found a statistically significant but modest reduction in osteoarthritis pain (SMD −0.30, 95% CI −0.50 to −0.09) and disability. Patients on ginger were more than twice as likely to stop treatment because of side effects, mostly gastrointestinal (RR 2.33, 95% CI 1.04–5.22) ^{6Reference 6Bartels EM et al et al. · 2015Meta-analysisEfficacy and safety of ginger in osteoarthritis patients: a meta-analysis of randomized placebo-controlled trials — meta-analysisView study →}.

The largest trial randomised 247 knee-osteoarthritis patients to a highly purified, standardised ginger extract and found a higher responder rate than placebo (63% vs 50%, P = 0.048) ^{7Reference 7Altman RD et al et al. · 2001RCTEffects of a ginger extract on knee pain in patients with osteoarthritis — randomized controlled trialView study →}.

A later systematic review found oral capsules beat placebo for pain, while topical ginger did not outperform standard care ^{8Reference 8Araya-Quintanilla F et al et al. · 2020Meta-analysisEffectiveness of ginger on pain and function in knee osteoarthritis: a PRISMA systematic review and meta-analysis — meta-analysisView study →}.

Gap: the benefit is small, rests mainly on standardised extracts, and comes with a higher rate of stomach upset.

A 2025 GRADE-assessed dose-response meta-analysis of 29 trials found ginger reduced C-reactive protein (WMD −0.86 mg/L), TNF-α (−1.90 pg/mL) and IL-6 (−1.15 pg/mL), and improved antioxidant capacity ^{9Reference 9Rjabi S et al et al. · 2025Meta-analysisAntioxidant and anti-inflammatory effects of ginger supplementation in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomised controlled trials — meta-analysisView study →}.

Two earlier meta-analyses reported significant drops in CRP, TNF-α, IL-6 and malondialdehyde, with a marginal effect on PGE2 ^{10,11Reference 10Jalali M et al et al. · 2020Meta-analysisThe effects of ginger supplementation on markers of inflammatory and oxidative stress: a systematic review and meta-analysis of clinical trials — meta-analysisView study →Reference 11Sheikhhossein F et al et al. · 2021Meta-analysisEffects of ginger supplementation on biomarkers of oxidative stress: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →}. Larger malondialdehyde reductions appeared at doses of 1 g/day or less over shorter courses ^{11Reference 11Sheikhhossein F et al et al. · 2021Meta-analysisEffects of ginger supplementation on biomarkers of oxidative stress: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →}.

Gap: these are surrogate biomarkers rather than clinical outcomes, and heterogeneity across trials is high ^{9Reference 9Rjabi S et al et al. · 2025Meta-analysisAntioxidant and anti-inflammatory effects of ginger supplementation in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomised controlled trials — meta-analysisView study →}.

A meta-analysis of 14 trials (1,417 participants) found that, compared with placebo, ginger lowered nausea severity (MD −0.71), reduced the incidence of nausea in the first six hours after surgery (RR 0.68), and cut rescue-antiemetic use (RR 0.71). Vomiting incidence did not differ significantly ^{20Reference 20Zhu W et al et al. · 2021Meta-analysisEfficacy of ginger in preventing postoperative nausea and vomiting: a systematic review and meta-analysis — meta-analysisView study →}.

Against prophylactic antiemetic drugs, ginger gave slightly less nausea but no difference in vomiting or rescue-antiemetic use ^{20Reference 20Zhu W et al et al. · 2021Meta-analysisEfficacy of ginger in preventing postoperative nausea and vomiting: a systematic review and meta-analysis — meta-analysisView study →}.

Regimens were capsules or powder given before the operation.

Gap: the trials vary in surgery type and dosing, and they were not designed to detect the theoretical bleeding risk from ginger’s antiplatelet activity.

A 2024 GRADE-assessed meta-analysis of 27 RCTs (1,309 participants) reported reductions in body weight (WMD −1.52 kg), BMI (−0.58 kg/m²) and waist circumference (−1.04 cm), with a non-linear effect emerging around 2 g/day over more than eight weeks ^{13Reference 13Rafieipour N et al et al. · 2024Meta-analysisGinger intervention on body weight and body composition in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials — meta-analysisView study →}.

An earlier meta-analysis of 14 trials in overweight and obese people found ginger lowered body weight, waist-to-hip ratio, fasting glucose and HOMA-IR and raised HDL. It did not change BMI, insulin, triglycerides, total cholesterol or LDL ^{14Reference 14Maharlouei N et al et al. · 2019Meta-analysisThe effects of ginger intake on weight loss and metabolic profiles among overweight and obese subjects: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →}.

Gap: the effects are small (about 1.5 kg), come from short trials, and the certainty of the evidence was rated low to very low ^{13Reference 13Rafieipour N et al et al. · 2024Meta-analysisGinger intervention on body weight and body composition in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials — meta-analysisView study →}.

A systematic review and meta-analysis of 23 RCTs found ginger did not significantly reduce the incidence of acute nausea (P = 0.53), delayed nausea (P = 0.31), acute vomiting (P = 0.09) or delayed vomiting (P = 0.89) ^{17Reference 17Choi J et al et al. · 2022Meta-analysisEffects of ginger intake on chemotherapy-induced nausea and vomiting: a systematic review of randomized clinical trials — meta-analysisView study →}.

A 2025 meta-analysis of 35 trials, 22 of them using ginger capsules, asked about severity. Capsules taken alongside standard antiemetics lowered the incidence of grade 3 acute nausea (RR 0.19) and high-grade vomiting (RR 0.47) ^{48Reference 48Lin CY et al et al. · 2025Meta-analysisEfficacy and safety of ginger on chemotherapy-induced nausea and vomiting: a systematic review and meta-analysis — meta-analysisView study →}.

A 2024 multicentre double-blind RCT in 103 adults gave standardised ginger providing 84 mg/day of gingerols and shogaols. It improved nausea-related quality of life, and delayed nausea and vomiting were less common on ginger in cycles 2 and 3 ^{18Reference 18Crichton M et al et al. · 2024RCTEffect of a standardized ginger root powder regimen on chemotherapy-induced nausea and vomiting: a multicenter, double-blind, placebo-controlled randomized trial — randomized controlled trialView study →}.

Gingerols and shogaols act on 5-HT3 receptors and have weak anti-neurokinin activity, the same pathways targeted by standard antiemetics ^{19,25,43Reference 19Marx W et al et al. · 2017ReviewGinger — mechanism of action in chemotherapy-induced nausea and vomiting: a review — reviewView study →Reference 25Al Kury LT et al et al. · 2018ReviewNatural negative allosteric modulators of 5-HT3 receptors — reviewView study →Reference 43Abdel-Aziz H et al. · 2006In vitroMode of action of gingerols and shogaols on 5-HT3 receptors: binding studies, cation uptake by the receptor channel and contraction of isolated guinea-pig ileum — in vitroView study →}.

Gap: the pooled analyses answer different questions, trials vary widely in chemotherapy regimen and background antiemetics, and the effect is as an add-on rather than on its own.

A meta-analysis of six RCTs (345 participants) found ginger lowered systolic (MD −6.36 mmHg, 95% CI −11.27 to −1.46) and diastolic (MD −2.12 mmHg) blood pressure ^{15Reference 15Hasani H et al et al. · 2019Meta-analysisDoes ginger supplementation lower blood pressure? A systematic review and meta-analysis of clinical trials — meta-analysisView study →}.

The effect was significant only in trials with a mean age of 50 or under, of eight weeks or less, and at doses of 3 g/day or more. Heterogeneity was very high (I² ≈ 90%) ^{15Reference 15Hasani H et al et al. · 2019Meta-analysisDoes ginger supplementation lower blood pressure? A systematic review and meta-analysis of clinical trials — meta-analysisView study →}.

Gap: few trials, very high heterogeneity, and an effect limited to younger participants, short trials and high doses ^{15Reference 15Hasani H et al et al. · 2019Meta-analysisDoes ginger supplementation lower blood pressure? A systematic review and meta-analysis of clinical trials — meta-analysisView study →}.

A double-blind trial in 100 patients found 250 mg of ginger powder comparable to sumatriptan for stopping a migraine attack without aura, with fewer side effects ^{21Reference 21Maghbooli M et al et al. · 2014RCTComparison between the efficacy of ginger and sumatriptan in the ablative treatment of the common migraine — randomized controlled trialView study →}.

A second RCT in 60 patients found 400 mg of ginger extract, added to intravenous ketoprofen in the emergency room, improved clinical response at 1–2 hours versus placebo ^{22Reference 22Martins LB et al et al. · 2019RCTDouble-blind placebo-controlled randomized clinical trial of ginger (Zingiber officinale Rosc.) addition in migraine acute treatment — randomized controlled trialView study →}.

A prophylaxis trial from the same group found no difference from placebo in the proportion of patients whose attack frequency halved ^{23Reference 23Martins LB et al et al. · 2020RCTDouble-blind placebo-controlled randomized clinical trial of ginger (Zingiber officinale Rosc.) in the prophylactic treatment of migraine — randomized controlled trialView study →}.

Gap: the acute-treatment trials are small and single-centre, and the one prevention trial was null.

The two provocation trials used different models and reached opposite results.

In a rotating-chair study of 28 volunteers, 500 mg or 1,000 mg of powdered ginger and 1,000 mg of fresh ginger gave no protection against motion sickness, and 500 mg had no effect on gastric emptying ^{24Reference 24Stewart JJ et al et al. · 1991RCTEffects of ginger on motion sickness susceptibility and gastric function — randomized controlled trialView study →}.

In a double-blind, randomised crossover study using circular vection in 13 people prone to motion sickness, 1,000 mg and 2,000 mg of ginger reduced nausea, delayed its onset and shortened recovery. It also suppressed the tachygastria and the rise in plasma vasopressin that vection provokes ^{50Reference 50Lien HC et al et al. · 2003RCTEffects of ginger on motion sickness and gastric slow-wave dysrhythmias induced by circular vection — randomized controlled trialView study →}.

In the same study, ginger did not block nausea caused by infusing vasopressin directly, which places its action on the stomach rather than centrally ^{50Reference 50Lien HC et al et al. · 2003RCTEffects of ginger on motion sickness and gastric slow-wave dysrhythmias induced by circular vection — randomized controlled trialView study →}.

A 2026 review concluded that ginger does not prevent motion sickness in adults ^{51Reference 51Abukmail E et al et al. · 2026ReviewEvidence that ginger (Zingiber officinale) does not prevent motion sickness in adults — reviewView study →}.

The European Medicines Agency keeps prevention of nausea and vomiting in motion sickness as a well-established use, at 1–2 g an hour before travel ^{53Reference 53Committee on Herbal Medicinal Products · 2025ReviewEuropean Union herbal monograph on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory monographView study →}. Its 2025 assessment found no new efficacy trials and judged the older studies low in quality by current standards ^{54Reference 54Committee on Herbal Medicinal Products · 2025ReviewAssessment report on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory reviewView study →}.

Gap: the trials are small, run on laboratory models rather than real travel, and the most recent review is negative.

A 2023 meta-analysis found ginger reduced total cholesterol (SMD −0.44) and triglycerides (SMD −0.61), with a dose-dependent effect on total cholesterol ^{16Reference 16Salih AK et al et al. · 2023Meta-analysisEffect of ginger (Zingiber officinale) intake on human serum lipid profile: systematic review and meta-analysis — meta-analysisView study →}.

A meta-analysis in type 2 diabetes found no significant change in triglycerides, total cholesterol, LDL or HDL ^{12Reference 12Ebrahimzadeh A et al et al. · 2022Meta-analysisThe effect of ginger supplementation on metabolic profiles in patients with type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →}. A meta-analysis in overweight and obese people likewise found no effect on triglycerides, total cholesterol or LDL ^{14Reference 14Maharlouei N et al et al. · 2019Meta-analysisThe effects of ginger intake on weight loss and metabolic profiles among overweight and obese subjects: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →}.

Gap: the meta-analyses disagree by population and preparation.

An earlier meta-analysis of 10 trials in type 2 diabetes found significant reductions in fasting blood sugar (WMD −18.81 mg/dL, 95% CI −28.70 to −8.92) and HbA1c (WMD −0.57%), with high heterogeneity (I² ≈ 77% for fasting glucose) ^{12Reference 12Ebrahimzadeh A et al et al. · 2022Meta-analysisThe effect of ginger supplementation on metabolic profiles in patients with type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →}.

A 2024 meta-analysis of five trials, using 1.2–2 g/day for 4–12 weeks, found no significant effect on either fasting blood sugar or HbA1c. Two of the individual trials did report falls in fasting glucose ^{49Reference 49Schumacher JC et al et al. · 2024Meta-analysisThe effect of oral supplementation of ginger on glycemic control of patients with type 2 diabetes mellitus: a systematic review and meta-analysis — meta-analysisView study →}.

Gap: the two pooled analyses disagree, the trials are short, and none addresses long-term diabetic outcomes. An additive effect with glucose-lowering drugs has not been tested.

A 12-week double-blind pilot in 44 patients gave 2 g/day of ginger alongside diet and activity advice. It reduced ALT, GGT, inflammatory cytokines, insulin resistance and the grade of hepatic steatosis compared with placebo, but not AST or fibrosis ^{45Reference 45Rahimlou M et al et al. · 2016RCTGinger supplementation in nonalcoholic fatty liver disease: a randomized, double-blind, placebo-controlled pilot study — randomized controlled trialView study →}.

A separate 12-week trial in 46 patients using 1.5 g/day of ginger powder lowered ALT, total and LDL cholesterol, fasting glucose, insulin resistance and hs-CRP compared with placebo. AST, GGT and TNF-α did not change ^{46Reference 46Rafie R et al et al. · 2020RCTEffect of ginger powder supplementation in patients with non-alcoholic fatty liver disease: a randomized clinical trial — randomized controlled trialView study →}.

Gap: both trials are small, short and run on top of diet and exercise programmes, and neither tested liver histology.

Side effects. Stomach upset, belching, indigestion, heartburn and nausea are common, and allergic reactions have been reported ^{53Reference 53Committee on Herbal Medicinal Products · 2025ReviewEuropean Union herbal monograph on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory monographView study →}. In osteoarthritis trials, digestive side effects roughly doubled the rate of stopping treatment compared with placebo ^{6Reference 6Bartels EM et al et al. · 2015Meta-analysisEfficacy and safety of ginger in osteoarthritis patients: a meta-analysis of randomized placebo-controlled trials — meta-analysisView study →}.

Overdose. No case of overdose has been reported, and long-term animal studies found toxic effects only at doses above normal human use ^{53Reference 53Committee on Herbal Medicinal Products · 2025ReviewEuropean Union herbal monograph on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory monographView study →}.

Anticoagulants and antiplatelet drugs. Ginger’s pungent compounds inhibit thromboxane synthesis and platelet aggregation ^{29Reference 29Hirsch GE et al et al. · 2017ReviewNatural products with antiplatelet action — reviewView study →}. Reviews of warfarin interactions list ginger among the herbs that may raise bleeding risk, mostly on the strength of case reports ^{27,28Reference 27Tan CSS et al et al. · 2021Systematic reviewWarfarin and food, herbal or dietary supplement interactions: a systematic review — systematic reviewView study →Reference 28Hazra S et al et al. · 2024ReviewSafety issues of herb–warfarin interactions — reviewView study →}. The EMA monograph lists no known interactions ^{53Reference 53Committee on Herbal Medicinal Products · 2025ReviewEuropean Union herbal monograph on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory monographView study →}, and a 2000 review found the evidence for a warfarin–ginger interaction lacking ^{47Reference 47Vaes LP · 2000ReviewInteractions of warfarin with garlic, ginger, ginkgo, or ginseng: nature of the evidence — reviewView study →}.

The EMA’s 2025 assessment records a different picture from national product information and case reports. Product information in Germany and the Netherlands warns of increased bleeding with anticoagulants and advises stopping before surgery ^{54Reference 54Committee on Herbal Medicinal Products · 2025ReviewAssessment report on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory reviewView study →}. Case reports describe INR rising to 10 in two women on phenprocoumon or warfarin who had been taking ginger, and a fatal bleed in a man on dabigatran after a ginger and cinnamon drink ^{54Reference 54Committee on Herbal Medicinal Products · 2025ReviewAssessment report on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory reviewView study →}.

In a controlled crossover study of 12 healthy men, ginger taken for a week before and after a warfarin dose did not change warfarin clearance, its CYP2C9-mediated metabolism, INR or platelet aggregation ^{54,57Reference 54Committee on Herbal Medicinal Products · 2025ReviewAssessment report on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory reviewView study →Reference 57Jiang X et al. · 2005RCTEffect of ginkgo and ginger on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects — randomised crossover studyView study →}. In a Canadian cohort of 171 people on warfarin, ginger use was linked to self-reported bleeding but not to a raised INR ^{54Reference 54Committee on Herbal Medicinal Products · 2025ReviewAssessment report on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory reviewView study →}.

It is sensible to tell the prescriber about ginger supplements, watch for unusual bruising or bleeding, and stop them before elective surgery. Culinary amounts are not the concern.

Drug metabolism. In laboratory tests, ginger extract and its gingerols and shogaols inhibited CYP3A4, CYP2C9, CYP1A2 and CYP2B6, and the drug transporters P-glycoprotein and BCRP ^{58Reference 58Husain I et al. · 2023In vitroEvaluation of the herb–drug interaction (HDI) potential of Zingiber officinale and its major phytoconstituents — in vitro studyView study →}. In rats, ginger juice raised blood levels of the transplant drug tacrolimus ^{59Reference 59Egashira K et al. · 2012AnimalFood-drug interaction of tacrolimus with pomelo, ginger, and turmeric juice in rats — animal studyView study →}.

The warfarin study found no effect on CYP2C9 in people, and the other enzymes have not been tested in people.

Blood sugar and blood pressure drugs. An additive effect with glucose- and blood-pressure-lowering drugs is plausible from the metabolic trials but has not been tested ^{12,15Reference 12Ebrahimzadeh A et al et al. · 2022Meta-analysisThe effect of ginger supplementation on metabolic profiles in patients with type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →Reference 15Hasani H et al et al. · 2019Meta-analysisDoes ginger supplementation lower blood pressure? A systematic review and meta-analysis of clinical trials — meta-analysisView study →}.

Gallstones and gastric disease. German product information advises people with gallstone disease to see a doctor before use ^{54Reference 54Committee on Herbal Medicinal Products · 2025ReviewAssessment report on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory reviewView study →}. High intake may aggravate reflux or peptic-ulcer symptoms ^{36Reference 36Bone · 2003A Clinical Guide to Blending Liquid Herbs: Herbal Formulations for the Individual Patient}.

Children. The EMA does not recommend ginger medicines under 18, except for motion sickness from age 6 at reduced doses ^{53Reference 53Committee on Herbal Medicinal Products · 2025ReviewEuropean Union herbal monograph on Zingiber officinale Roscoe, rhizoma, final — revision 1 — regulatory monographView study →}.

Quality. Essence of ginger has a history of adulteration, so buy from a reputable supplier ^{37Reference 37Grieve · 1931Ginger — A Modern Herbal. http://www.botanical.com/botanical/mgmh/g/ginger13.htmlView study →}.