Interleukin-6 concentration

Method

Serum or plasma interleukin-6 (IL-6) by immunoassay. Timing relative to exercise recorded on the edge.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Timing is load-bearing here in a way it is not for CRP. IL-6 rises sharply during exercise and falls within hours, so a resting value and a post-exercise value are different claims about the same analyte. An edge without the timing on it is close to uninterpretable.

Findings

4 findings from 3 compounds, strongest first.

• creatine — no detected effect on

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.FindingNull result

  “Chronic effects of creatine on CRP (SMD = -0.11; 95% CI: -0.69 to 0.48; p = 0.73; I² = 0%) and IL-6 (SMD = -0.06; 95% CI: -0.64 to 0.53; p = 0.84; I² = 0%) were also no significant.”

  Study

  meta-analysis

  Population

  healthy individuals, athletes and clinical populations

  Impact of creatine supplementation on inflammation: evidence from a systematic review and meta-analysis of randomized double-blind placebo trials.2026PMID:41798953

• curcumin — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×1

  “The combined effect size for curcumin supplementation in reducing IL-6 levels was MD = -0.33, indicating a substantial improvement.”

  Study

  meta-analysis

  Population

  trained and untrained adults undergoing muscle-damaging exercise

  Effect -0.33 mean difference

  Meta-analysis of the effect of curcumin supplementation on skeletal muscle damage status.2024PMID:39008500

• L-arginine — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Finding

  “Our analysis also showed that L-arginine had a noticeable impact on decreasing interleukin-6 (IL-6) levels (WMD = -7.72 pg/ml; 95% CI: -15.05, -0.39).”

  Study

  meta-analysis

  Population

  adults undergoing coronary artery bypass grafting; overall pooled estimate

  L-arginine impact on inflammatory and cardiac markers in patients undergoing coronary artery bypass graft: a systematic review and meta-analysis of randomized controlled trials.2024PMID:39538180

• curcumin — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×1

  “Median IL-6 levels were markedly lower in the curcumin group than in the placebo group (5.50 [4.39–9.00] vs. 13.69 [11.27–15.65], p < 0.001), with a large effect size ( r = 0.78, 95% CI: 0.68–0.86).”

  Study

  RCT

  Duration

  12 months

  Dose

  Curcumin 1500 mg/day orally for 12 months

  Population

  Adults with type 2 diabetes mellitus and obesity (n=114 randomised); secondary endpoint; between-group comparison at 12 months

  Curcumin Supplementation Reduces Inflammation, Neutrophil-to-Lymphocyte Ratio (NLR), and Antioxidant Status in Obese Patients with Type 2 Diabetes: A Randomized Controlled Trial.2026PMID:42123439Industry funded