Turmeric (Haldi) and Curcumin: What It Really Does — and the Risks Nobody Mentions

Haldi is one of the oldest home remedies in South Asia: haldi doodh for a cold, a paste on a cut, a pinch in every salan. In recent years it has gone global as 'golden milk' and turmeric capsules, sold for joint pain, weight loss, skin, mood and almost everything else. Most of these claims come from laboratory and animal studies. The human trials tell a narrower story.

How much curcumin is in turmeric?

Curcumin is the main active compound in turmeric, and there is not much of it. A 2006 analysis of 28 commercial spice products found pure turmeric powder averaged 3.14 percent curcumin by weight; curry powders had far less. A teaspoon of turmeric weighs about 3 g, which gives roughly 90 mg of curcumin — and in a family pot of salan, each plate gets only a fraction of that teaspoon. The arthritis trials used concentrated extracts, such as 1,500 mg a day in the largest one.

Does black pepper help you absorb turmeric?

Yes. Curcumin is broken down quickly in the gut and liver, so very little reaches the blood. In a 1998 study in Planta Medica, 2 g of curcumin on its own gave blood levels that were 'undetectable or very low' in volunteers; taking it with 20 mg of piperine, the active compound in black pepper, increased absorption by 2,000 percent. Desi cooking often combines haldi with kali mirch and oil, which helps. Many supplements add piperine for the same reason — but piperine can also change how some medicines are absorbed.

Does turmeric help joint pain and arthritis?

This is where the evidence is strongest. In a 2014 trial of 367 people with knee osteoarthritis, 1,500 mg a day of turmeric extract was as effective as 1,200 mg a day of ibuprofen for pain and function over 4 weeks, with fewer cases of stomach pain. A 2016 meta-analysis of 8 trials found turmeric and curcumin reduced arthritis pain compared with placebo and performed similarly to painkillers, although the trials were small. A 2020 trial in the Annals of Internal Medicine found a turmeric extract reduced knee pain by 9 points on a 100-point scale compared with placebo over 12 weeks, but did not reduce joint swelling on MRI. That is a modest benefit — strength training and weight loss still do more for knee arthritis, as our knee pain guide explains.

Does turmeric help with weight loss?

Only a little. A 2019 meta-analysis of 21 studies with 1,604 people with metabolic syndrome or related conditions found curcumin supplements produced small reductions in body weight, BMI and waist size. The effects were measured in standardised units and were small; no trial showed turmeric causing meaningful fat loss on its own. A calorie deficit and enough protein matter far more. Haldi doodh made with full-fat milk and sugar adds calories, not fat loss.

Can turmeric supplements damage your liver?

Rarely, but yes. The US Drug-Induced Liver Injury Network reviewed its cases from 2004 to 2022 and found 10 cases of liver injury linked to turmeric supplements, all since 2011. Five people were admitted to hospital and one died of acute liver failure. Seven of the ten carried a gene variant, HLA-B*35:01, which suggests some people are far more susceptible than others. Three of the products tested also contained piperine. These were concentrated supplements, not turmeric used in cooking. Stop any turmeric supplement and see a doctor if you develop yellow eyes or skin, dark urine, unusual tiredness or pain under the right ribs.

Is there lead in turmeric in Pakistan?

Sometimes, and it matters more than any supplement question. Lead chromate, a bright yellow industrial pigment, is added by some processors to make turmeric look brighter. A 2024 study tested 356 turmeric samples, both whole roots and powder, from 23 cities in India, Pakistan, Sri Lanka and Nepal. Most had no detectable lead, but 14 percent did, and samples from Karachi and Peshawar, as well as Patna in India, contained more than 1,000 μg/g. Lead is especially harmful to children's developing brains.

• Buy turmeric from established brands with food-authority licensing rather than loose powder of unknown origin.
• Be wary of turmeric — powder or whole roots — that looks unusually bright, uniform orange-yellow; lead chromate is added for exactly that look.
• Do not give turmeric supplements to children.
• If you take blood thinners such as warfarin or clopidogrel, diabetes medicines, or have gallstones or liver disease, ask your doctor before taking turmeric supplements. Normal cooking amounts are fine.

This article is general information, not medical advice. Talk to your doctor before taking turmeric or curcumin supplements if you take any regular medicine, have liver disease or gallstones, or are due to have surgery.