Endpoint

Visual analogue scale pain intensity

CAT:outcome/vas-painreported in mm (0-100)12 findings from 9 compounds

What moved it

12 findings · 9 compounds · 2 null · by evidence strength

Compound	Direction	Findings	Strongest evidence
curcumin	down 2 · no effect 1	3	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
duloxetine	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
prednisone	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
quercetin	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
zolpidem	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
glucosamine	down 1 · no effect 1	2	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.
Camellia sinensis	down	1	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.
Collagen	down	1	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.
resveratrol	down	1	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.

Reported to move it

10 findings

curcumin — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Findingreplicated ×1
“The PVAS was much lower in the curcumin group than in the placebo groups (overall mean differences and CI: −2.04 and −2.85, −1.24; P <.00001).”
Quoted verbatim from Efficacy of Turmeric Extracts and Curcumin for Alleviating the Symptoms of Joint Arthritis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials..
Study

meta-analysis
Population

adults with osteoarthritis or rheumatoid arthritis; curcumin vs placebo, pain visual analogue score
Effect -2.04 mean difference, 95% CI -2.85 to -1.24
Efficacy of Turmeric Extracts and Curcumin for Alleviating the Symptoms of Joint Arthritis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.2016PMID:27533649Permalink
zolpidem — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“On POD1, patients in Group Z had lower VAS scores compared to Group C (resting: 2 [1] vs. 3 [1]; P < 0.01, coughing: 4.5 [1] vs. 5 [0.25]; P < 0.05).”
Quoted verbatim from Effect of improving sleep quality the night before surgery with zolpidem on postoperative gastrointestinal function in patients undergoing laparoscopic partial colorectal resection: a randomized, double-blind, controlled trial..
Study

RCT
Duration

1 day
Dose

10 mg capsule at bedtime the night before surgery, single dose
Population

Adults aged 18-80 with PSQI > 5 undergoing elective laparoscopic partial colorectal resection under general anaesthesia; single timepoint, postoperative day 1, pain at rest and during coughing; all patients received the same intraoperative and PCIA sufentanil analgesia
Effect of improving sleep quality the night before surgery with zolpidem on postoperative gastrointestinal function in patients undergoing laparoscopic partial colorectal resection: a randomized, double-blind, controlled trial.2025PMID:39966710Permalink
duloxetine — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“Pooled data shows that duloxetine can reduce postoperative VAS at movement (MD = −1.08; 95% CI, [−1.45–−0.7]; P <.05. Fig. 5).”
Quoted verbatim from Effect of duloxetine on pain relief after total knee arthroplasty: A meta-analysis of randomized controlled trials..
Study

meta-analysis
Population

Adults after a first total knee arthroplasty; six pooled randomised trials of perioperative duloxetine versus placebo; pain on movement pooled across postoperative timepoints from 24 hours to 5 days
Effect -1.08 mean difference, 95% CI -1.45 to -0.7
Effect of duloxetine on pain relief after total knee arthroplasty: A meta-analysis of randomized controlled trials.2023PMID:36897714Permalink
prednisone — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“PG showed significantly lower pain values compared to CG, both at T1 (PG: 3.1 ± 1.5; CG: 4.6 ± 1.8; p = 0.0006) and T2 (PG: 1.0 ± 0.8; CG: 1.9 ± 1.4; p = 0.0063).”
Quoted verbatim from Three-dimensional facial swelling evaluation of pre-operative single-dose of prednisone in third molar surgery: a split-mouth randomized controlled trial..
Study

RCT
Dose

single dose of 25 mg, 1 hour before third molar extraction
Population

Healthy adults aged 18 to 32 years undergoing surgical extraction of both mandibular third molars, split-mouth design, 32 patients and 64 extractions; postoperative pain on a 0 to 10 visual analogue scale at 2 days (T1) and 7 days (T2) after surgery; all patients also received paracetamol, chlorhexidine rinses and antibiotic prophylaxis
Three-dimensional facial swelling evaluation of pre-operative single-dose of prednisone in third molar surgery: a split-mouth randomized controlled trial.2023PMID:37653378Permalink
quercetin — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“The Quercetin group demonstrated significantly lower VAS scores at all measured time points (p<0.001) and delayed time to first analgesic request (3.9±1.3 vs 2.73±0.78 hours, p<0.001) compared to the placebo group.”
Quoted verbatim from The Adjunctive Effect of Quercetin on Postoperative Pain Management Following Cesarean Section: A Randomized Controlled Study..
Study

RCT
Duration

1 day
Dose

500 mg single dose one hour before surgery
Population

Women undergoing elective cesarean section under spinal anaesthesia, pain on a 10 cm VAS at 2, 6, 12 and 24 hours after surgery
The Adjunctive Effect of Quercetin on Postoperative Pain Management Following Cesarean Section: A Randomized Controlled Study.2025PMID:40687903Permalink
glucosamine — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Finding
“For pain intensity, group A showed obviously lower visual analog scale scores than group B at month 6 (20.6 vs 29.2 mm; P = .007) and month 12 (17.4 vs 28.6 mm; P = .001).”
Quoted verbatim from Oral Glucosamine Hydrochloride Combined With Hyaluronate Sodium Intra-Articular Injection for Temporomandibular Joint Osteoarthritis: A Double-Blind Randomized Controlled Trial..
Study

RCT
Dose

oral glucosamine hydrochloride (1.44 g/day) for 3 months
Population

adults with temporomandibular joint osteoarthritis; both groups also received hyaluronate sodium intra-articular injections
Oral Glucosamine Hydrochloride Combined With Hyaluronate Sodium Intra-Articular Injection for Temporomandibular Joint Osteoarthritis: A Double-Blind Randomized Controlled Trial.2018PMID:29864430Permalink

Show the remaining 4

resveratrol — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Finding
“Resveratrol treatment significantly reduced pain intensity and WOMAC scores, while increasing OKS scores, ROM, gait velocity, HGS, and overall SPPB performance (p < 0.05).”
Quoted verbatim from Resveratrol supplementation improves functional performance in knee osteoarthritis by upregulating sirtuin 1: a randomized study..
Study

RCT
Duration

3 months
Dose

500 mg/day
Population

Patients with knee osteoarthritis, aged 63-73 years, in a 12-week double-blind placebo-controlled trial (n=122 analyzed after dropouts: placebo n=65, resveratrol n=57)
Resveratrol supplementation improves functional performance in knee osteoarthritis by upregulating sirtuin 1: a randomized study.2025PMID:41037125Permalink
Collagen — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Finding
“Finally, a significant reduction was found in the VAS score after collagen administration (WMD - 16.57; 95% CI - 26.24, - 6.89; p < 0.001).”
Quoted verbatim from Effect of collagen supplementation on osteoarthritis symptoms: a meta-analysis of randomized placebo-controlled trials..
Study

meta-analysis
Population

Adults with osteoarthritis in randomised placebo-controlled trials of orally administered collagen
Effect of collagen supplementation on osteoarthritis symptoms: a meta-analysis of randomized placebo-controlled trials.2019PMID:30368550Permalink
Camellia sinensis — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Finding
“Mean differences of VAS pain, total WOMAC, and WOMAC physical function scores in green tea group showed a significant reduction, compared with the control group (P = 0.038, P = 0.006, and P = 0.004, respectively).”
Quoted verbatim from Green tea (Camellia sinensis) for patients with knee osteoarthritis: A randomized open-label active-controlled clinical trial..
Study

RCT
Duration

4 weeks
Population

Adults with knee osteoarthritis; diclofenac tablet given as background in both arms
Green tea (Camellia sinensis) for patients with knee osteoarthritis: A randomized open-label active-controlled clinical trial.2018PMID:28038881Permalink
curcumin — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Findingreplicated ×1
“The NMA results showed that compared with placebo, curcumin significantly reduced the visual analogue scale pain score (MD = -1.63, 95% CI: -2.91 to -0.45) and total WOMAC score (MD = -18.85, 95% CI: -29.53 to -8.76).”
Quoted verbatim from Efficacy and safety of curcumin therapy for knee osteoarthritis: A Bayesian network meta-analysis..
Study

meta-analysis
Population

Patients with knee osteoarthritis; Bayesian network meta-analysis, the contrast recorded here is curcumin monotherapy versus placebo. The review included 23 studies and 2175 KOA patients across 6 interventions overall; the abstract does not state how many patients or trials fed this particular pairwise estimate. The abstract does not state the VAS anchors, the scale length, or the recall frame.
Efficacy and safety of curcumin therapy for knee osteoarthritis: A Bayesian network meta-analysis.2024PMID:38036015Permalink

Measured, no effect detected

2 findings

curcumin — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull result
“In the between-group analysis, no significant differences were observed in VAS hand pain at rest, VAS hand pain during activity, VAS hand morning stiffness, DASH score, hand grip, pinch strength and rescue drug usage at 1, 3, and 6 months.”
Quoted verbatim from Efficacy and safety of curcumin in patients with hand osteoarthritis: a pilot double-blinded randomised controlled trial..
Study

RCT
Participants

27
Dose

170 mg/day curcuminoids (turmeric powder capsules, 28.75 mg curcuminoids per capsule, two capsules three times daily) for 3 months
Population

patients over 50 years with hand osteoarthritis, pain during activity, between-group at 1, 3 and 6 months
Efficacy and safety of curcumin in patients with hand osteoarthritis: a pilot double-blinded randomised controlled trial.2025PMID:41053771Permalink
glucosamine — no detected effect on
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.FindingNull result
“There was no statistical difference between the two groups in scores on the visual analog scale at 30 days for resting (mean [SD] score placebo group 3.5 [2.7] vs 3.3 [2.4] glucosamine group, P = 0.66) or walking (5.1 [2.6] vs 5.3 [2.4], P = 0.69); there was also no difference at 60 days for resting (3.4 [2.5] vs 3.2 [2.5], P = 0.81) or walking (4.9 [2.2] vs 4.9 [2.8], P = 0.90).”
Quoted verbatim from Randomized, controlled trial of glucosamine for treating osteoarthritis of the knee..
Study

RCT
Duration

2 months
Dose

glucosamine 500 mg three times daily (salt not stated in abstract)
Population

patients aged 34 to 81 being treated for osteoarthritis of the knee at a Veterans Affairs Medical Center; pain at rest and while walking, at 30 and 60 days
Randomized, controlled trial of glucosamine for treating osteoarthritis of the knee.2000PMID:10693368Permalink

How it is measured

Pain intensity marked by the patient on a continuous 0-100 mm or 0-10 cm visual analogue line anchored at no pain and at worst imaginable pain. Anatomical site, underlying condition, and the recall frame (pain at rest, pain on movement, or pain over a stated period) recorded with each finding. A 0-10 numerical rating scale, on which the patient states a whole number rather than marking a line, is a different instrument and is recorded as such.