Guide
ginger side effects
At typical amounts, ginger's common side effects are mild — heartburn, bad taste, stomach discomfort. GI side effects were about three times more common at a higher, concentrated-extract dose in one trial, and separate research found a real, dose-dependent effect on platelet aggregation relevant to bleeding risk.
At typical amounts, ginger's most commonly reported side effects are mild and digestive — heartburn, a bad taste, and stomach discomfort. At higher amounts used in some trials, gastrointestinal complaints became more common, and separately, ginger has a documented effect on blood clotting that matters if you take a blood thinner or have a bleeding disorder.
Common, mild effects
A National Institutes of Health reference database on medications describes ginger, taken as a medicinal supplement, as generally well tolerated in adults, but lists bad taste, heartburn, abdominal discomfort, weight gain, headache, dry mouth and occasional nausea as side effects reported from time to time. None of these are described as common in the sense of affecting most people — just as the effects that come up when they do occur.
More gastrointestinal side effects at higher amounts
The clearest side-effect data by dose comes from a 261-person osteoarthritis trial that used a concentrated ginger extract at 255 mg twice daily for six weeks. Gastrointestinal adverse events were reported by 59 people in the ginger group versus 21 on placebo — close to three times as many — though the trial's authors described most of them as mild. That's the highest documented rate of digestive side effects among the trials reviewed on this site, and it used a concentrated extract rather than plain powder, which may deliver more active compound per milligram.
Effect on blood clotting
Separately from digestive side effects, ginger has a measured effect on platelet function — the blood cells involved in clotting. One small 1993 study found that 5 grams of dry ginger, taken with a fatty meal, significantly reduced platelet aggregation (a measure of how readily blood cells clump together) compared with no change in a placebo group. A related 1997 study in people with coronary artery disease found daily doses of 4 grams for three months had no measurable effect on platelet aggregation, but a single 10-gram dose did significantly reduce it. Taken together, this is a real, dose-dependent effect on a clotting-related blood measurement — not itself a "side effect" you'd feel, but the mechanism behind the caution covered in ginger and medications: what to check and who should not take ginger.
What to do if something feels wrong
Heartburn or stomach upset that doesn't settle, an allergic reaction (rash, swelling, difficulty breathing), or unusual bruising or bleeding after starting ginger are all reasons to stop and talk to a doctor rather than wait it out. None of the research above gives a reliable way to predict who will react and who won't.
Questions people ask
What are the side effects of ginger?
The most commonly reported effects at typical amounts are mild: heartburn, a bad taste, stomach discomfort, headache and dry mouth. At higher amounts used in some trials, gastrointestinal side effects became more frequent, and ginger also has a measured effect on blood clotting worth knowing about if you take a blood thinner.
Does ginger cause heartburn?
It's one of the side effects most consistently reported across the trials and reference sources reviewed here, especially at higher amounts or on an empty stomach.
Can ginger cause an allergic reaction?
As with any plant-based supplement, allergic reactions are possible, though we didn't find data on how common they are for ginger specifically. A new allergic symptom after starting ginger is worth stopping for and discussing with a doctor.
Does ginger thin your blood?
Research has found it reduces platelet aggregation — a measure related to clotting — at higher doses (10 grams in one study), while a lower daily dose (4 grams over 3 months) in the same line of research showed no effect. See ginger and medications: what to check for what that means if you take a blood thinner.
Are ginger root capsules 550 mg safe?
That amount falls below every dose associated with more frequent side effects in the trials reviewed here, but we found no trial specifically testing 550 mg on its own for tolerability. General side-effect information above still applies at any amount.
Sources
- Ginger A National Institutes of Health reference database describes ginger's active compounds (gingerols, shogaols), confirms its GRAS food-flavoring status, notes it's commonly used for nausea and motion sickness, and flags mild common side effects plus a bleeding-risk interaction with warfarin.
- Effects of a ginger extract on knee pain in patients with osteoarthritis In a 261-person, 6-week trial, people with knee osteoarthritis taking a concentrated ginger extract (255 mg twice daily) were more likely to see a meaningful drop in pain-on-standing scores than those on placebo (63% vs 50%), though the ginger group also had close to three times as many mild digestive side effects.
- Effect of ginger (Zingiber officinale Rosc.) and fenugreek (Trigonella foenumgraecum L.) on blood lipids, blood sugar and platelet aggregation in patients with coronary artery disease In people with coronary artery disease, taking 4 grams of powdered ginger a day for 3 months did not change platelet clumping, blood fats or blood sugar, but a single, much larger 10-gram dose did significantly reduce platelet clumping.
- Effect of ginger on platelet aggregation in man In a small study, 5 grams of dry ginger taken with a high-fat meal significantly reduced platelet clumping compared with a group given the same fatty meal without ginger.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.