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Awaiting clinical review. This entry is sourced but has not yet been signed off by a pharmacist or clinician.

Curcuminoid extract of Curcuma longa

Curcumin

Concentrated curcumin probably eases knee osteoarthritis pain and stiffness a little, but the trials behind that finding are short, varied and often small, and the reviews that pool them are rated low quality. It is well tolerated in most people, yet the main caution is rare but real liver injury, mostly reported with high-absorption products and often with black pepper extract added. Ask a pharmacist first if you take a blood thinner or have liver problems.

Updated
29 September 2026
Orange curcumin capsules beside fresh turmeric root
At a glance
Last reviewed 29 September 2026
Evidence
Moderate
Best for
Knee osteoarthritis pain
Typical form & use
Curcuminoid extract; doses vary widely
Onset
4+ weeks
Safety
Rare liver injury, esp. high-absorption products. 2 known interactions, most serious with black pepper (piperine).
Check with your medications →

What it's used for

Evidence is rated per use. The same ingredient can be strong for one thing and traditional for another.

UseEvidenceWhat the research shows
Knee osteoarthritis pain and functionModerateA 2021 meta-analysis of 16 trials (1,810 adults, up to 16 weeks) of turmeric extracts found lower pain than placebo (SMD -0.82, 95% CI -1.17 to -0.47) and better function, with very high heterogeneity (I² 86-90%) and results similar to NSAIDs. A separate 2021 meta-analysis of 11 curcuminoid trials (1,258 people) also favoured curcuminoids for pain, with no clear difference between doses above and below 1,000 mg a day. A 2026 critical review of seven such reviews rated their methods extremely low quality and most outcome evidence low or very low, so the direction is consistent but the size of benefit is uncertain.1,3,4
Other inflammatory and liver conditionsLimitedNCCIH says studies exist for fatty liver disease, high cholesterol and mouth inflammation after cancer treatment, that initial results are promising, and that there is not enough evidence to conclude turmeric or curcumin helps any of them. Topical curcumin for knee osteoarthritis has unclear effects. We did not read the individual trials, so we rate these on NCCIH's summary alone.5

How much

Ranges below are what studies used and what supplements commonly contain. They are not a recommendation for you. Start at the low end.

Studied range
Under and over 1,000 mg a day3
The 2021 curcuminoid meta-analysis compared trials using at least 1,000 mg a day with those using less and found no significant difference in pain relief or adverse events. Products and extracts differed between trials, so doses are not directly comparable.
Duration
Up to about 16 weeks studied1,5
The largest meta-analysis included trials of up to 16 weeks. NCCIH says conventional oral turmeric or curcumin is likely safe for up to 2 or 3 months; safety beyond that is not established.
With piperine
2 g curcumin plus 20 mg piperine6
In a small study of healthy volunteers, this combination gave far higher blood levels than 2 g curcumin alone. This is a pharmacokinetic finding, not a recommended dose, and it says nothing about whether the higher levels work better for joint pain.
Timing · No source we read gave a best time of day.With food? · No source we read gave food guidance. NCCIH lists nausea, acid reflux, stomach upset, diarrhoea and constipation as possible side effects of oral turmeric.How long to trial · The trials behind the knee osteoarthritis findings ran for up to 16 weeks, so a month or more is a fairer test than a few days. If you notice fatigue, nausea, poor appetite, dark urine or jaundice, NCCIH says to stop and speak to a healthcare provider.

How people take it

Standard curcuminoid capsuleVaries by product; follow the labelCurcumin on its own is poorly absorbed. NCCIH describes conventionally formulated products as likely safe for up to 2 or 3 months.
With piperine (black pepper extract)Varies by product; follow the labelPiperine raised curcumin blood levels about 20-fold in a small human study. Piperine was present in 3 of 7 products tested in a US liver injury case series, so more absorption is not automatically safer.
High-absorption formulationsVaries by product; follow the labelLipid, phytosome and similar formulations are sold to raise absorption. NCCIH warns that liver damage has been reported with such products, and an Italian case series linked hepatitis to high-bioavailability, high-dose products.

Safety

Who should avoid
  • Liver disease or unexplained abnormal liver tests — ask your clinician first
  • Pregnancy — NCCIH says turmeric supplements may be unsafe
  • Breastfeeding — little known about amounts above normal food levels
  • Blood thinners or antiplatelets — ask a pharmacist first
  • Anyone who develops fatigue, dark urine or jaundice — stop and seek advice
Known interactions
MonitorBlack pepper (piperine) — Piperine raised curcumin absorption sharply in one human study, so the same supplement dose gives a much larger exposure.
MonitorBlood thinners — A small 10-day study of a branded curcumin product found no change in bleeding time on aspirin, ticlopidine or clopidogrel, or in INR on warfarin or dabigatran, but it was short, small and run by people linked to the manufacturer, so it cannot rule out a problem.

Compare with

Head-to-head pages for the pairs people search most.

Curcumin vs Turmeric

Questions people ask

Does curcumin really work for knee arthritis?

Pooled trials suggest it reduces knee pain and stiffness more than placebo, with an effect similar to NSAIDs in a few head-to-head trials. However, the trials are short and varied, and a 2026 review judged the meta-analyses to be of very low methodological quality, so the true size of the benefit is uncertain.

Can curcumin damage the liver?

Rarely, yes. A US registry reported 10 turmeric-associated liver injury cases, one fatal, with a link to the HLA-B*35:01 gene variant, and an Italian review described hepatitis linked to high-dose, high-absorption products. NCCIH advises stopping and seeing a provider if you develop fatigue, nausea, poor appetite, dark urine or jaundice.

Do I need piperine or black pepper with curcumin?

Piperine raised blood curcumin sharply in a small study of healthy volunteers, but no source we read shows that the extra absorption improves joint outcomes. It may also carry a trade-off, since piperine was in some of the products in the US liver injury cases.

Is curcumin the same as turmeric?

No. Curcumin is one component of turmeric root, and supplements concentrate it to far above the amount you would eat in food. Trial results and safety concerns for extracts do not automatically apply to cooking with the spice.

Sources

  1. Meta-analysis Wang Z, Singh A, Jones G, et al. Efficacy and Safety of Turmeric Extracts for the Treatment of Knee Osteoarthritis: a Systematic Review and Meta-analysis of Randomised Controlled Trials. Curr Rheumatol Rep. 2021.
  2. Human interaction study Hu S, Belcaro G, Dugall M, et al. Interaction study between antiplatelet agents, anticoagulants, thyroid replacement therapy and a bioavailable formulation of curcumin (Meriva). Eur Rev Med Pharmacol Sci. 2018.
  3. Meta-analysis Hsiao AF, Lien YC, Tzeng IS, Liu CT, Chou SH, Horng YS. The efficacy of high- and low-dose curcumin in knee osteoarthritis: A systematic review and meta-analysis. Complement Ther Med. 2021.
  4. Systematic review Chen J, Zhou Q, Yu W, et al. A critical review of systematic reviews and meta-analyses of curcumin for knee osteoarthritis. Front Pharmacol. 2026.
  5. Regulator/health agency NCCIH. Turmeric: Usefulness and Safety. National Center for Complementary and Integrative Health.
  6. Human pharmacokinetic study Shoba G, Joy D, Joseph T, Majeed M, Rajendran R, Srinivas PS. Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Med. 1998.
  7. Case series and systematic review Lombardi N, Crescioli G, Maggini V, et al. Acute liver injury following turmeric use in Tuscany: An analysis of the Italian Phytovigilance database and systematic review of case reports. Br J Clin Pharmacol. 2021.
  8. Case series Halegoua-DeMarzio D, Navarro V, Ahmad J, et al. Liver Injury Associated with Turmeric - A Growing Problem: Ten Cases from the Drug-Induced Liver Injury Network. Am J Med. 2023.

Last reviewed 29 September 2026 · Next review March 2027 · How we rate evidence