Pi7.5

Black Pepper Extract Research

47 peer-reviewed studies · Evidence score: 7.5/10

Curcumin supplementation effect on liver enzymes in patients with nonalcoholic fatty liver disease: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

Vajdi M et al. • Nutrition reviews (2025)

Curcumin supplementation improved AST and ALT levels compared with the control group.

Curcumin supplementation significantly reduced ALT (weighted mean difference [WMD], -4.10, 95%CI, -7.16 to -1.04) and AST (WMD, -3.27; 95%CI, -5.16 to -1.39), but not ALP (WMD, -0.49; 95%CI, -1.79 to 0.82).
Curcumin plus piperine supplementation had no significant effect on ALT (WMD, -3.79; 95%CI, -13.30 to 5.72), and AST (WMD, -1.1; 95%CI, -3.32 to 1.09).
Curcumin supplementation improved AST and ALT levels compared with the control group.

Meta-Analysisn=905

DOI

Does curcumin improve liver enzymes levels in nonalcoholic fatty liver disease? A systematic review, meta-analysis, and meta-regression

Aragón-Vela J et al. • Phytotherapy research : PTR (2024)

Consequently, longer trials utilizing high doses of curcumin could diminish the positive impact of curcumin in reducing serum levels of aminotransferases in patients with NAFLD.

Subgroup analysis revealed that adding piperine to curcumin did not benefit aminotransferase levels in NAFLD patients.
Additionally, we found a negative correlation between the duration of the intervention and the relative (mg/kg/day) curcumin dose with the reduction in liver aminotransferases.
In summary, the sources of heterogeneity identified in our study are likely attributed to the duration of the intervention and the relative dose of curcumin.

Meta-Analysisn=835

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Meta-analysis of randomized controlled trials of 4 weeks or longer suggest that curcumin may afford some protection against oxidative stress

Qin S et al. • Nutrition research (New York, N.Y.) (2018)

The standardized mean difference (SMD) with a 95% confidence interval (CI) was used to present the results.

The standardized mean difference (SMD) with a 95% confidence interval (CI) was used to present the results.
There was a significant reduction in circulating MDA concentrations (SMD = -0.769, 95% CI: -1.059 to -0.478) and a significant increase in SOD activity (SMD = 1.084, 95% CI: 0.487 to 1.680) following curcumin supplementation.
This effect was greater when combined with piperine than curcuminoids alone (SMD = -1.085, 95% CI: -1.357 to -0.813; SMD = -0.850, 95% CI: -1.158 to -0.542).

Meta-Analysisn=626

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A Systematic Review of the Anti-seizure and Antiepileptic Effects and Mechanisms of Piperine

Rahimi-Dehkordi N et al. • Central nervous system agents in medicinal chemistry (2025)

In vivo and in vitro studies showed beneficial effects on treating epilepsy.

In vivo and in vitro studies showed beneficial effects on treating epilepsy.
Although clinical studies also showed similar results, these needed to be increased, and more clinical studies needed to be designed in this field.
Further research warranted to confirm findings

Systematic Review

DOI

A systematic review and meta-analysis of randomized controlled trials investigating the effect of the curcumin and piperine combination on lipid profile in patients with metabolic syndrome and related disorders

Hosseini H et al. • Phytotherapy research : PTR (2023)

However, further long-term RCTs are required to ascertain their clinical benefit.

The combined results by the random-effects model demonstrated that curcumin plus piperine significantly decreased total cholesterol and LDL-C in patients suffering from metabolic syndrome.
In comparison, the results of the overall effect size did not show any significant change in triglyceride concentrations.
Our results were robust in sensitivity analysis and were not dependent on the dose of curcumin, the dose of piperine, and the duration of treatment.

Meta-Analysis

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Effects of Combination of Curcumin and Piperine Supplementation on Glycemic Profile in Patients with Prediabetes and Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

Widjanarko ND et al. • Journal of the ASEAN Federation of Endocrine Societies (2024)

The supplementation of curcumin and piperine showed a numerical reduction in FPG, HOMA-IR and BMI, but were not statistically significant.

The supplementation of curcumin and piperine showed a numerical reduction in FPG, HOMA-IR and BMI, but were not statistically significant.
Further research is needed as there is a paucity of studies included in the review.
Further research warranted to confirm findings

Meta-Analysis

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Human blood metabolites and gastric cancer: a Mendelian randomization analysis

Zhang C et al. • BMC gastroenterology (2024)

The present study provides evidence supporting a causal relationship between these three circulating metabolites and GC risk.

The present study provides evidence supporting a causal relationship between these three circulating metabolites and GC risk.
Elevated levels of 3-methyl-2-oxovalerate and piperine may increase the risk of GC, while Phe-Phe dipeptide may have a protective effect.
By integrating genomics and metabolomics, we offer a novel perspective on the biological mechanisms underlying GC.

Meta-Analysis

DOI

Systematic Review of Chemical Compounds with Immunomodulatory Action Isolated from African Medicinal Plants

Nikiema WA et al. • Molecules (Basel, Switzerland) (2024)

The outcomes of this overview are to provoke structural action optimization, to orient research on particular natural chemicals for managing inflammatory, infectious diseases and cancers, or to boost vaccine immunogenicity.

These discussed compounds exert their effects through various mechanisms, targeting the modulation of MAPKs, PI3K-Akt, and NF-kB.
These mechanisms can support the traditional use of medicinal plants to treat immune-related diseases.
The outcomes of this overview are to provoke structural action optimization, to orient research on particular natural chemicals for managing inflammatory, infectious diseases and cancers, or to boost vaccine immunogenicity.

Systematic Review

DOI

Protective Effects of Micronutrient Supplements, Phytochemicals and Phytochemical-Rich Beverages and Foods Against DNA Damage in Humans: A Systematic Review of Randomized Controlled Trials and Prospective Studies

Fenech MF et al. • Advances in nutrition (Bethesda, Md.) (2023)

These findings highlight the importance of nutrients involved in (i) DNA metabolism and repair (folate, vitamin B12, and zinc) and (ii) prevention of oxidative stress and inflammation (vitamins A, ...

These findings highlight the importance of nutrients involved in (i) DNA metabolism and repair (folate, vitamin B12, and zinc) and (ii) prevention of oxidative stress and inflammation (vitamins A, C, E, lycopene, curcumin, proanthocyanidins, selenium, and zinc).
Supplementation with certain micronutrients and their combinations may reduce DNA damage and promote cellular health by improving the maintenance of genome integrity.

Systematic Review

DOI

Efficacy of hyaluronidase combined with corticosteroids in treatment of oral submucous fibrosis: A meta-analysis of randomized controlled clinical trials

Guo J et al. • Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology (2020)

According to this meta-analysis, weak evidence indicates that hyaluronidase combined with corticosteroids has no additional clinical benefit over control drugs (lycopene, pentoxifylline, aloe vera, dexamethasone, Turmix and isoxsuprine) in improving maximum mouth opening and alleviating the burning sensation in patients with OSF.

Therefore, more high-quality, multi-centre randomized controlled trials with larger samples are needed to further assess the efficacy of hyaluronidase combined with corticosteroids in the treatment of OSF.
Further research warranted to confirm findings

Meta-Analysisn=244

DOI

Antioxidant and anti-inflammatory effects of curcuminoid-piperine combination in subjects with metabolic syndrome: A randomized controlled trial and an updated meta-analysis

Panahi Y et al. • Clinical nutrition (Edinburgh, Scotland) (2015)

Short-term supplementation with curcuminoid-piperine combination significantly improves oxidative and inflammatory status in patients with MetS.

Supplementation with curcuminoid-piperine combination significantly improved serum SOD activities (p < 0.001) and reduced MDA (p < 0.001) and CRP (p < 0.001) concentrations compared with placebo.
Quantitative data synthesis revealed a significant effect of curcuminoids vs. placebo in reducing circulating CRP concentrations (weighed mean difference: -2.20 mg/L; 95% confidence interval [CI]: -3.96, -0.44; p = 0.01).
Curcuminoids could be regarded as natural, safe and effective CRP-lowering agents.

Meta-Analysisn=117

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The Effects of Curcumin Plus Piperine Co-administration on Inflammation and Oxidative Stress: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Hosseini H et al. • Current medicinal chemistry (2025)

These results indicated that curcumin plus piperine administration could effectively reduce oxidative stress and inflammation.

According to the current meta-analysis, curcumin plus piperine administration showed a significantly increased SOD activity and GSH levels while significantly decreased MDA concentrations.
In addition, our study revealed that curcumin plus piperine significantly decreased TNF-α and IL-6 concentrations.
These results indicated that curcumin plus piperine administration could effectively reduce oxidative stress and inflammation.

Meta-Analysisn=13

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Piperine—A Major Principle of Black Pepper: A Review of Its Bioactivity and Studies

Haq IU, Imran M, Nadeem M, Tufail T, Gondal TA, Mubarak MS • Applied Sciences (2021)

Piperine enhances bioavailability of numerous compounds through inhibition of drug metabolism enzymes and promotion of absorption.

Piperine increases curcumin bioavailability by 2000% through glucuronidation inhibition
Anti-inflammatory effects through NF-kB pathway suppression demonstrated in clinical settings
Thermogenic and metabolic-enhancing properties support weight management

Systematic Review

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A systematic review on black pepper (Piper nigrum L.): from folk uses to pharmacological applications

Takooree H et al. • Critical reviews in food science and nutrition (2019)

As a conclusive remark, P. nigrum should not only be regarded as "King of spices" but can also be considered as part of the kingdom of medicinal agents, comprising a panoply of bioactive compounds with potential nutraceutical and pharmaceutical applications.

The major bioactive compound identified in P. nigrum is piperine although other compounds are also present including piperic acid, piperlonguminine, pellitorine, piperolein B, piperamide, piperettine, and (-)-kusunokinin, which also showed biological potency.
Most pharmacological studies were conducted in vitro (n = 60) while only 21 in vivo and 1 clinical trial were performed.
Hence, more in vivo experiments using a pharmacokinetic and pharmacokinetic approach would be beneficial.

Systematic Review

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A systematic review on Piper longum L.: Bridging traditional knowledge and pharmacological evidence for future translational research

Yadav V et al. • Journal of ethnopharmacology (2020)

Amongst various activities, bioscientific clarification in relation to its ethnopharmacological perspective has been evidenced mainly for anti-amebic, anthelminthic, anti-tumor and anti-diabetic activity.

Amongst various activities, bioscientific clarification in relation to its ethnopharmacological perspective has been evidenced mainly for anti-amebic, anthelminthic, anti-tumor and anti-diabetic activity.
However, despite traditional claims, insufficient scientific validation for the treatment of insomnia, dementia, epilepsy, rheumatoid arthritis, asthma, spleen disorder, puerperal fever and leprosy, necessitate future investigations in this direction.
It is also essential and critical to generate toxicological data and pharmacokinetics on human subjects so as to confirm its conceivable bio-active components in the body.

Systematic Review

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Chemoprevention of Breast Cancer With Vitamins and Micronutrients: A Concise Review

Mokbel K et al. • In vivo (Athens, Greece) (2019)

Therefore, a supplement that contains these micronutrients, using the safest form and dosage should be investigated in future breast cancer chemoprevention studies and as part of standard breast ca...

Therefore, a supplement that contains these micronutrients, using the safest form and dosage should be investigated in future breast cancer chemoprevention studies and as part of standard breast cancer therapy.
Delinasios),
Further research warranted to confirm findings

Meta-Analysis

DOI

Antihypertensive Effects of Curcumin/Turmeric Supplementation in Prediabetes and Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Bahari H et al. • Endocrinology, diabetes & metabolism (2026)

Curcumin/turmeric supplementation demonstrates a modest, yet significant reduction in SBP in individuals with prediabetes and diabetes, with a more pronounced effect in those with baseline hypertension.

Pooled results indicated that curcumin/turmeric supplementation significantly reduced SBP (WMD: -2.69 mmHg; 95% CI: -3.84 to -1.55; p < 0.001; I2 = 30.1%) compared to control groups.
However, no significant effect was found on DBP (WMD: -1.20 mmHg; 95% CI: -2.84 to 0.44; p = 0.15; I2 = 84.3%).
Subgroup analyses showed significant reductions in SBP in individuals with T2D or prediabetes, in those who were overweight, and with interventions using nano-curcumin, turmeric, or curcumin with piperine at doses > 1 g/day.

Meta-Analysisn=855AI-discovered

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Effects of Curcuminoids Plus Piperine Co-Supplementation on Serum Lipid Profile in Adults: A Systematic Review and Meta-Analysis of RCTs

Karimi M et al. • Lipids (2026)

To estimate the pooled effect size, weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) were calculated, applying a random-effects model to account for potential variability between studies.
However, the reduction in low-density lipoprotein cholesterol (LDL-C) was not statistically significant (WMD: -2.20 mg/mL, 95% CI: -7.22, 2.80, p = 0.387).
Curc + Pipe has clinically meaningful lipid-modulating effects, particularly in reducing TG and TC and modestly increasing HDL-C levels.

Meta-Analysisn=1,038AI-discovered

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Effects of postbiotics on chronic diarrhea in young adults: a randomized, double-blind, placebo-controlled crossover trial assessing clinical symptoms, gut microbiota, and metabolite profiles

Guo S et al. • Gut microbes (2024)

In conclusion, postbiotics have shown promise in relieving chronic diarrhea.

The results showed that postbiotic intake resulted in significant improvements in Bristol stool scale score, defecation frequency, urgency, and anxiety.
Targeted metabolomics confirmed a significant increase in fecal butyric acid after postbiotic intervention.
Additionally, chenodeoxycholic acid, a diarrhea-linked primary bile acid, decreased substantially.

Crossovern=69

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A Standardized Withania somnifera (Linn.) Root Extract with Piperine Alleviates the Symptoms of Anxiety and Depression by Increasing Serotonin Levels: A Double-Blind, Randomized, Placebo-Controlled Study

Majeed M et al. • Journal of integrative and complementary medicine (2024)

The trial was registered prospectively with the Clinical Trial Registry of India (CTRI) with the registration number CTRI/2022/05/042640, on May 18, 2022.

Conclusion: The results of the study suggest that 500 mg of ARE standardized for 2.5% withanolides with 5 mg piperine is beneficial in improving depression, and anxiety, by increasing serum serotonin levels.
Serum levels of serotonin increased in ARE, but showed a decrease in placebo, the difference being statically significant (p < 0.001).
Biochemical and hematological parameters remained in the normal range in all participants and ARE was well tolerated during the study.

RCTn=70

DOI

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