Summary of findings for the main comparison. Dietary supplements versus placebo for primary dysmenorrhoea.
| Dietary supplements versus placebo for moderate or severe primary dysmenorrhoea | ||||||
| Population: women with moderate or severe primary dysmenorrhoea Setting: community Intervention: dietary supplement Comparison: placebo | ||||||
| Outcomes1 | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with dietary supplement (95% CI) | |||||
| Dill seed versus placebo Pain score |
Mean pain score 5.45 (SD 1.41) on a 0‐10 point scale |
The mean pain score in the intervention group was 1.15 points lower (2.22 lower to 0.08 lower) than in the placebo group | — | 95 (1 study) |
⊕⊕⊝⊝ very low2,3,4 | |
| Dill seed versus placebo Pain relief |
391 per 1000 | 304 per 1000 (114 to 598) | OR 0.68 (0.20 to 2.31) | 46 (1 study) |
⊕⊝⊝⊝ very low2,3,4 | |
| Fennel versus placebo Pain score |
Mean pain score 2.18 (SD 0.66) on a 0 to 3 point scale |
The mean pain score in the intervention group was 0.34 points lower (0.74 lower to 0.06 higher) than in the placebo group | — | 43 (1 study) | ⊕⊝⊝⊝ very low2,5 | |
| Fenugreek versus placebo Pain score |
Mean pain score 4.32 (SD 1.5) on a 0 to 10 point scale |
The mean pain score in the intervention group was 1.71 points lower (2.35 lower to 1.07 lower) than in the placebo group | — | 101 (1 study) | ⊕⊕⊝⊝ low2,3 | |
| Ginger versus placebo Pain score |
Mean pain score ranged from 4.81 (SD 1.7) to 6.2 (SD 1.4) on a 0 to 10 point scale |
We did not pool data due to high heterogeneity. However, the direction of effect was consistent, and all studies found a benefit in the intervention group, ranging from mean ‐0.93 points to mean ‐2.30 points | — | 266 (3 studies) | ⊕⊕⊝⊝ low2,6 | |
| Ginger versus placebo Pain relief |
471 per 1000 | 829 per 1000 (615 to 936) | OR 5.44 (1.80 to 16.46) | 69 (1 study) | ⊕⊕⊝⊝ low2,3 | |
| Ginger versus placebo Adverse effects |
44 per 1000 | 43 per 1000 (6 to 248) | OR 0.96 (0.13 to 7.09) | 92 (1 study) | ⊕⊝⊝⊝ very low2,3 | |
| Guava leaf versus placebo Pain score |
Mean pain score ranged from 4.31 (SD 2.12) to 5.13 (SD 2.23) on a 0 to 10 point scale |
The mean pain score in the intervention group was 0.59 points lower (0.13 lower to 1.31 higher) than in the placebo group | — | 151 (1 study) | ⊕⊕⊝⊝ low 2,3 | |
| Valerian versus placebo Pain score |
Mean pain score 2.65 (SD 1.81) on a 0 to 10 point scale |
The mean pain score in the intervention group was 0.76 points lower (1.44 lower to 0.08 lower) than in the placebo group | — | 100 (1 study) | ⊕⊕⊝⊝ low 2,3 | |
| Zataria versus placebo Pain relief |
353 per 1000 | 784 per 1000 (592 to 901) | OR 6.66 (2.66 to 16.72) | 99 (1 study) | ⊕⊕⊝⊝ low2,3 | |
| Fish oil versus placebo Pain score |
Mean pain score 5.22 (SD 1.96) on a 0 to 10 point scale |
The mean pain score in the intervention group was 1.59 points lower (2.25 lower to 0.93 lower) than in the placebo group | — | 120 (1 study) |
⊕⊕⊝⊝ low2,3 | |
| Fish oil + vitamin B1 versus placebo Pain score |
Mean pain score 4.01 (SD 1.2) on a 0 to 10 point scale |
The mean pain score in the intervention group was 2.8 points lower (3.33 lower to 2.27 lower) than in the placebo group | — | 120 (1 study) |
⊕⊕⊝⊝ low2,3 | |
| Vitamin B1 versus placebo Pain score |
Mean pain score 4.11 (SD 1.73) on a 0 to 10 point scale |
The mean pain score in the intervention group was 2.7 points lower (3.32 lower to 2.08 lower) than in the placebo group | — | 120 (1 study) |
⊕⊕⊝⊝ low2,3 | |
| Vitamin E versus placebo Pain score |
Mean pain score 5.4 (SD 2.4) on a 0 to 10 point scale |
The mean pain score in the intervention group was the same (SMD 0.00, 0.34 standard deviations (SDs) lower to 0.34 SDs higher) as in the placebo group7 | — | 135 (2 studies) |
⊕⊕⊝⊝ low2,3 | |
| Zinc sulphate versus placebo Pain score |
Mean pain score 6.18 (SD 1.7) on a 0 to 10 point scale |
The mean pain score in the intervention group was 0.95 points lower (1.54 lower to 0.36 lower) than in the placebo group | — | 99 (1 study) |
⊕⊝⊝⊝ very low2,3 | |
| Zinc sulphate versus placebo Adverse effects |
44 per 1000 | 37 per 1000 (5 to 221) | OR 0.83 (0.11 to 6.12) | 99 (1 study) |
⊕⊝⊝⊝ very low2,3 | |
Abbreviations: OR: odds ratio; SD: standard deviation; SMD: standardised mean difference 1 Outcome at first measurement after treatment commencement. 2 Downgraded one level for serious risk of bias due to inadequate reporting of study methods. 3 Downgraded one level for serious imprecision: single small study and/or results compatible with benefit in one or both groups and with no effect
4 Downgraded one level for serious inconsistency: findings for pain score were inconsistent with findings for rate of pain relief. 5 Downgraded two levels for very serious imprecision: single very small study 6 Downgraded one level for serious inconsistency (I2=78%) 7 Data pooled to calculate standardised mean difference, as the two studies utilised different pain scales.