Turmeric and Curcumin: Benefits, Dosage, and Safety

What turmeric and curcumin is

Turmeric is a plant in the ginger family (Curcuma longa) grown mainly in India and Southeast Asia. Its rhizome is dried and ground into the familiar yellow cooking spice. Curcumin, one of a group of compounds called curcuminoids, is the major active component and gives turmeric its color. Turmeric and curcumin are sold as dietary supplements in capsules, tablets, powders, teas, and fluid extracts, and turmeric is also applied topically.

What it does

• Provides the yellow pigment (curcumin) and characteristic flavor of the turmeric spice used in food
• Has been used traditionally in Ayurvedic, Chinese, Islamic, and Thai systems of medicine for a range of complaints
• Studied as a plant-derived compound with antioxidant and anti-inflammatory activity in laboratory research, though clinical benefit in people is not established
• Not an essential nutrient: the body does not require turmeric or curcumin for normal physiological function

Intake and dosing

Turmeric and Curcumin is not an essential nutrient, so no Recommended Dietary Allowance or Tolerable Upper Intake Level has been set. Doses in studies vary widely. Because supplement doses are not standardised, discuss an appropriate amount with a clinician or pharmacist.

Deficiency and who is at risk

None. Turmeric and curcumin are not essential nutrients, so there is no deficiency state and no requirement to consume them.

Who may need more

• People are not required to take turmeric or curcumin; it is not an essential nutrient and no one develops a deficiency without it
• Adults who choose to try it for joint or general wellness reasons, understanding that NIH considers the evidence inconclusive
• Anyone considering it should first talk with a health care provider, especially if pregnant, breastfeeding, taking medicines, or having gallbladder or liver problems

Food sources

Turmeric root and the ground turmeric spice; curry powders and prepared curries; prepared mustard; and turmeric teas. Culinary spice amounts provide only small quantities of curcumin.

Forms and absorption

Sold as turmeric powder, capsules, tablets, standardized curcumin or curcuminoid extracts, fluid extracts, and teas. Curcumin on its own is poorly absorbed. Manufacturers use enhanced-absorption (high-bioavailability) formulations, and combining curcumin with piperine (a compound from black pepper) is one way to improve its bioavailability. NCCIH cautions that these highly bioavailable formulations may harm the liver, so higher absorption is not automatically safer.

Safety, excess and interactions

Too much

Reported adverse effects from oral turmeric or curcumin include nausea, vomiting, acid reflux, upset stomach, diarrhea, and constipation. Applied to the skin it can cause hives or itching. NCCIH warns that highly bioavailable (enhanced-absorption) formulations may harm the liver, and liver damage has been reported in some people who used them; warning signs include unusual fatigue, nausea, poor appetite, dark urine, or yellowing of the skin or eyes (jaundice).

Interactions to know

• High-bioavailability curcumin formulations have been linked to liver injury in some people; the risk may be greater when combined with other substances that can stress the liver (NCCIH)
• NCCIH advises that if you take any medicine you should talk with your health care provider before using any herbal product, because some herbs and medicines interact in harmful ways
• Curcumin may add to the effect of anticoagulant or antiplatelet medicines (for example warfarin, aspirin, clopidogrel); this interaction is based on limited evidence and warrants medical advice before combining
• Curcumin may lower blood sugar and could add to the effect of diabetes medicines; monitor and consult a provider (limited evidence)

How status is measured

Not routinely measured. There is no clinical blood test used to assess turmeric or curcumin status, because it is not an essential nutrient. Blood curcumin levels are used only in research settings, where they are typically very low because oral curcumin is poorly absorbed.

Regulated as a dietary supplement, not an FDA-approved drug. Dietary supplements containing turmeric are not reviewed or approved by the FDA before sale; manufacturers and distributors are responsible for evaluating the safety and labeling of their products before marketing. Turmeric used as a spice and color additive in food has long-standing food use. Supplement labels may not claim to diagnose, treat, cure, or prevent any disease.

What the evidence supports

We grade the strength of evidence behind each common reason people take turmeric and curcumin, mirroring how the NIH describes it.