Does cinnamon help with weight loss?

A little, in the trials that exist, and they were not run in the people who usually ask. Across 21 randomized trials in 1,480 adults, cinnamon supplements lowered body weight by 2 lb (0.92 kg) more than control (95% CI 0.33 to 1.51), with very high heterogeneity between trials (I2 84.2%). Most of those trials were small and short, in people with diabetes, polycystic ovary syndrome or metabolic syndrome, and they used different species and doses. NCCIH, the US federal agency for complementary health, calls it unclear whether cinnamon helps with weight loss.

Unsettled. A small average difference shows up in every pooled analysis, under a kilogram in most of them. Three things keep it from being an answer. The trials disagree with each other more than they agree, they were mostly in people with a metabolic illness, and in type 2 diabetes alone one meta-analysis found no significant change in weight at all. Among the trials described here, none tested cinnamon alone, with weight as the outcome, in people who are overweight but otherwise healthy.

What the trials found

The pooled analyses

The largest meta-analysis, 21 trials and 1,480 adults, also found BMI 0.40 lower (95% CI 0.22 to 0.57) and waist to hip ratio 0.02 lower. Waist size and body fat fell by amounts that just missed statistical significance. A dose-response meta-analysis of 12 trials in 786 adults found about 2.2 lb (1 kg) more weight loss, and larger effects in people under 50 and in those starting with a BMI of 30 or more. Those subgroups are exploratory. An umbrella analysis that pooled 7 earlier meta-analyses arrived at 1.5 lb (95% CI 0.77 to 2.2; metric: 0.67 kg, 0.35 to 0.99) and BMI 0.45 lower, though many of the same trials sit inside each of the seven.

Type 2 diabetes, where results disagree

A meta-analysis of 9 trials in type 2 diabetes found no significant change in body weight, a standardized difference of -0.309 (95% CI -0.793 to 0.175), or in BMI. A 2025 meta-analysis of 28 trials in type 2 diabetes found BMI 1.18 lower (95% CI 0.39 to 1.97), and only in the subgroup taking 2 g a day or less. The two reviews point in different directions, and neither settles the other.

Polycystic ovary syndrome and metabolic syndrome

A 2024 meta-analysis of 12 trials in women with polycystic ovary syndrome found 1 lb (0.47 kg) more weight loss on cinnamon (95% CI 0.15 to 0.80), with trials that were small and short. One of the trials behind it gave 84 overweight women with the condition 1.5 g a day for 8 weeks, and weight fell more than on placebo. The abstract does not say by how much. In a 16-week double-blind trial of 116 Asian Indians with metabolic syndrome, 3 g a day cut the waist by 1.9 in (95% CI 0.75 to 3; metric: 4.8 cm, 1.9 to 7.7) and BMI by 1.3 more than placebo. That trial was registered only after it ran and took place at a single center.

Cinnamon on top of exercise

In a 2026 trial of 26 inactive overweight women exercising three times a week for 4 weeks, adding cinnamon made no difference to waist size compared with exercise alone. That trial was very small and short, and its abstract does not give the dose.

Who should be careful

The trials described here used 1.5 to 4 g of cinnamon a day, taken for weeks to months. That is more than a sprinkle on porridge, and it is the kind of use the safety warnings are about.

Not for everyone. NCCIH says prolonged use of cassia cinnamon could be an issue for sensitive people, such as those with liver disease, because some cassia products carry high levels of coumarin. It also says that larger amounts or long use are sometimes linked to side effects, most often gut problems or allergic reactions, without giving a dose or a frequency. If you have liver disease, a cinnamon supplement is worth discussing with your doctor before you start.

In a 4-week crossover trial of 18 adults with obesity and prediabetes, 4 g of cinnamon a day caused no more abdominal pain, bloating, wind or change in stool frequency than placebo. That trial was short, and its abstract does not report liver tests or how much coumarin people took in.

What expert bodies say

NCCIH says research does not clearly support cinnamon for any health condition, and that it is unclear whether cinnamon supplements help with diabetes or weight loss. That is a position without an analysis of its own, and it is more cautious in tone than the meta-analyses above. The two are less far apart than they look, since a difference under a kilogram in short trials of people with metabolic conditions is exactly the kind of result that leaves the question open. We could not verify a European safe intake figure for coumarin from a source we could reach, so none is given here.

More on the spice itself, as food, is on the cinnamon page.

How we searched

What would change this answer

• A trial lasting 6 to 12 months, large enough and registered in advance, of a named cinnamon species and dose in people with overweight but without diabetes or polycystic ovary syndrome. Weight should be its main outcome, with liver tests alongside. None is registered.
• A meta-analysis that separates cassia from Ceylon cinnamon and capsules from food, and explains why the trials disagree so much.
• The full text of the 2025 umbrella review, if it reports a pooled weight figure.

Sources

1. ev-cinw-01 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 1,480
   The meta-analysis showed that cinnamon supplementation significantly reduces BMI [weighted mean difference (WMD) = -0.40 kg/m2 , 95% confidence interval (CI): -0.57, -0.22 kg/m2 , p < .001, I2 = 78.9%], body weight (WMD = -0.92 kg; 95% CI: -1.51, -0.33 kg; p = .002; I2 = 84.2%), and WHR (WMD = -0.02, 95% CI: -0.038, -0.018; p < 0.001; I2 = 0%).
   
   Who: adults in randomized controlled trials of cinnamon supplements, searched to August 2019
   Effect: body weight WMD -2 lb (95% CI -3.3 to -0.73; metric: -0.92 kg, -1.51 to -0.33), I2 84.2%; BMI -0.40 kg/m2 (-0.57 to -0.22); waist -0.69 in (-1.76 cm) (p = .056) and fat mass -0.87% (p = .057) not significant
   Certainty: High heterogeneity; most trials small, short, in people with diabetes, PCOS or metabolic syndrome; species and dose varied.
   Phytother Res, 2020 · checked 2026-10-07 · we read the abstract
2. ev-cinw-02 · Meta-analysis or systematic review · systematic review and dose-response meta-analysis of randomized controlled trials · n = 786
   Greater effects on BW were observed in subjects aged <50 years old and those with a baseline BMI of ≥30 kg/m2.
   
   Who: adults in randomized controlled trials of cinnamon, searched to September 2018
   Effect: body weight WMD -2.2 lb (95% CI -3.7 to -0.84; metric: -1.02 kg, -1.66 to -0.38); BMI -0.51 kg/m2; waist -0.94 in (-2.40 cm); fat mass -1.02%; fat mass fell at 2 g/day or more for 12 weeks or more
   Certainty: Fewer trials than ev-cinw-01; subgroup findings are exploratory.
   Clin Nutr, 2020 · checked 2026-10-07 · we read the abstract
3. ev-cinw-03 · Meta-analysis or systematic review · umbrella meta-analysis of meta-analyses of randomized controlled trials · n = 7 meta-analyses
   The pooled effects of 7 meta-analyses showed that cinnamon supplementation significantly reduced body weight (ES: -0.67 kg; 95% CI: -0.99, -0.35, p ˂ .001), body mass index (ES: -0.45 kg/m2 ; 95% CI: -0.57, -0.33, p ˂ .001) in comparison to control group.
   
   Who: adults in meta-analyses of cinnamon RCTs, searched to March 2021
   Effect: body weight -1.5 lb (95% CI -2.2 to -0.77; metric: -0.67 kg, -0.99 to -0.35); BMI -0.45 kg/m2 (-0.57 to -0.33); waist -0.41 in (-0.89 to 0.06; metric: -1.05 cm, -2.26 to 0.15), not significant; larger at 3 g/day or more and in PCOS
   Certainty: Overlapping trials across the pooled meta-analyses; calls itself a final conclusion, which a small effect from small trials does not support.
   J Food Biochem, 2022 · checked 2026-10-07 · we read the abstract
4. ev-cinw-04 · Meta-analysis or systematic review · systematic review and meta-analysis of clinical trials · n = 9 studies
   Based on the results of the present study, cinnamon supplementation had no significant effect on the body weight (BW) (SMD: -0.309, 95% CI: [-0.793, 0.175], P = 0.211), body mass index (BMI) (SMD: -0.550, 95% CI: [-1.244, 0.144], P = 0.120).
   
   Who: patients with type 2 diabetes in clinical trials of cinnamon, searched to August 2019
   Effect: body weight SMD -0.309 (95% CI -0.793 to 0.175), p = 0.211; BMI SMD -0.550 (-1.244 to 0.144)
   Certainty: Standardized mean differences, so no kilogram figure; few trials.
   Diabetes Metab Syndr, 2020 · checked 2026-10-07 · we read the abstract
5. ev-cinw-05 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials (PROSPERO CRD42022370332) · n = 3054
   Only cinnamon doses of ≤2 g/day reduced HbA1c (WMD: -0.68 mg/dL, 95% CI: -1.16 to -0.1; I2 = 92%), HOMA-IR (WMD: -0.94 mg/dL; 95% CI: -1.21 to -0.67; I2 = 0%), and BMI (WMD: -1.18 kg/m2; 95% CI: -1.97 to -0.39; I2 = 0%).
   
   Who: adults and older adults with type 2 diabetes in RCTs lasting 30 to 120 days
   Effect: BMI WMD -1.18 kg/m2 (95% CI -1.97 to -0.39), I2 0%, in the 2 g/day or less subgroup
   Certainty: Subgroup result; HbA1c and HOMA-IR units in the abstract are printed as mg/dL by error. Disagrees with ev-cinw-04, which found no weight effect in diabetes.
   Nutr Rev, 2025 · checked 2026-10-07 · we read the abstract
6. ev-cinw-06 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 12 trials
   Under the random-effects model, the pooled weighted mean difference (WMD) was -0.47 kg (95 % CI: -0.80 to -0.15, p < 0.001; I2 = 0.0 %).
   
   Who: women with polycystic ovary syndrome in randomized controlled trials of cinnamon
   Effect: body weight WMD -1 lb (95% CI -1.8 to -0.33; metric: -0.47 kg, -0.80 to -0.15), I2 0%
   Certainty: Half a kilogram; trials small and short.
   European Journal of Obstetrics, Gynecology, and Reproductive Biology, 2024, Effect of cinnamon as a Chinese herbal medicine on markers of cardiovascular risk in women with polycystic ovary syndrome · checked 2026-10-07 · we read the abstract
7. ev-cinw-07 · Randomized controlled trial(s) · randomized double-blind controlled trial · n = 116
   Significantly greater decrease [difference between means, (95% CI)] in fasting blood glucose (mmol/L) [0.3 (0.2, 0.5) p = 0.001], glycosylated haemoglobin (mmol/mol) [2.6 (0.4, 4.9) p = 0.023], waist circumference (cm) [4.8 (1.9, 7.7) p = 0.002] and body mass index (kg/m2 ) [1.3 (0.9, 1.5) p = 0.001] was observed in the cinnamon group compared to placebo group.
   
   Who: Asian Indians with metabolic syndrome, north India; 3 g cinnamon vs 2.5 g wheat flour daily, 16 weeks
   Effect: waist circumference difference 1.9 in (95% CI 0.75 to 3; metric: 4.8 cm, 1.9 to 7.7); BMI 1.3 kg/m2 (0.9 to 1.5)
   Certainty: Retrospectively registered (NCT02455778); single center.
   Lipids Health Dis, 2017 · checked 2026-10-07 · we read the abstract
8. ev-cinw-08 · Randomized controlled trial(s) · randomized double-blind placebo-controlled trial · n = 84
   Cinnamon significantly decreased serum fasting blood glucose, insulin, homeostatic model assessment for insulin resistance, total cholesterol and low-density lipoprotein cholesterol and weight and increased high-density lipoprotein cholesterol compared with placebo (all p<0.05).
   
   Who: overweight or obese women with PCOS; 3 x 500 mg cinnamon capsules daily vs placebo, 8 weeks
   Effect: weight decreased vs placebo (p < 0.05); size of difference not given in the abstract
   Certainty: Effect size not in the abstract; short trial.
   Asia Pac J Clin Nutr, 2018 · checked 2026-10-07 · we read the abstract
9. ev-cinw-09 · Randomized controlled trial(s) · randomized controlled trial · n = 26
   However, between-group comparisons revealed a significant difference only for chest circumference (p = 0.003), with no significant group differences in abdominal circumference or any reproductive hormone concentration (all p > 0.05).
   
   Who: inactive overweight and obese women; exercise 3 times weekly with or without cinnamon, 4 weeks
   Effect: no between-group difference in abdominal circumference (p > 0.05); difference only in chest circumference
   Certainty: Very small and short; cinnamon dose not given in the abstract.
   J Int Soc Sports Nutr, 2026 · checked 2026-10-07 · we read the abstract
10. ev-cinw-10 · Randomized controlled trial(s) · randomized controlled double-blind crossover trial · n = 18
    No differences were found in digestive symptoms (abdominal pain, borborygmi, bloating, excess flatus, and stools/day) between cinnamon and placebo groups.
    
    Who: participants with obesity and prediabetes
    Effect: no difference in abdominal pain, borborygmi, bloating, flatus or stool frequency
    Certainty: Short trial; liver tests and coumarin exposure not reported in the abstract.
    Am J Clin Nutr, 2024 · checked 2026-10-07 · we read the abstract
11. ev-cinw-11 · Position of an expert body · agency fact sheet · n = —
    It’s unclear whether cinnamon supplementation is helpful for diabetes or weight loss.
    
    Who: people considering cinnamon supplements
    Effect: benefit for weight loss unclear; higher quality research needed
    Certainty: Position without its own analysis; disagrees in tone with the meta-analyses above, which find a small effect.
    NCCIH, Cinnamon: Usefulness and Safety (fact sheet), last updated November 2024 · checked 2026-10-07 · we read the section
12. ev-cinw-12 · Position of an expert body · agency fact sheet · n = —
    When used in larger amounts or for long periods of time, cinnamon is sometimes associated with side effects, most commonly gastrointestinal problems or allergic reactions.
    
    Who: people using cinnamon in larger amounts or for long periods
    Effect: most common side effects: gastrointestinal problems or allergic reactions
    Certainty: No dose threshold or frequency given.
    NCCIH, Cinnamon: Usefulness and Safety (fact sheet), last updated November 2024 · checked 2026-10-07 · we read the section
13. ev-cinw-13 · Position of an expert body · agency fact sheet · n = —
    Prolonged use of cassia cinnamon could be an issue for sensitive people, such as those with liver disease.
    
    Who: users of cassia cinnamon, especially people with liver disease
    Effect: coumarin-liver interactions reported; risk with high-coumarin cassia products and prolonged use
    Certainty: Weight-loss doses in trials (1.5 to 3 g/day for months) are the prolonged use this warns about.
    NCCIH, Cinnamon: Usefulness and Safety (fact sheet), last updated November 2024 · checked 2026-10-07 · we read the section