What do systematic reviews say?

Cannabis oil (15% cannabidiol and 4% THC) vs placebo oil

• Cannabis for the treatment of Crohn's disease 2018 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 39 participants
  Low

Cannabis cigarettes (115 mg THC) vs placebo cigarettes

The review found no eligible studies for this question.

• Cannabis for the treatment of Crohn's disease 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Summary of findings: inhaled antioxidants vs placebo

• Antioxidant supplementation for lung disease in cystic fibrosis 2019 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 153 participants
  Moderate

Chlorhexidine varnish vs placebo or no treatment

The review found no eligible studies for this question.

• Chlorhexidine treatment for the prevention of dental caries in children and adolescents 2015 · Cochrane All outcomes
  No trials reported on pain, quality of life, patient satisfaction or costs.
  0 studies
  No studies found

Silver diamine fluoride (SDF) vs placebo

SDF did not significantly differ from placebo for oral health-related quality of life in children (MD 0.03, 95% CI -0.16 to 0.22; ungraded).

• Silver diamine fluoride and oral health-related quality of life: A review and network meta-analysis. 2022 All outcomes

  Post-treatment · Pediatric dental care; trials conducted in China, the USA, and Brazil
  MD 0.03 [-0.16, 0.22]
  2 studies · 440 participants
  GRADE not reported

Oral hydroxychloroquine vs placebo

• Interventions for cutaneous disease in systemic lupus erythematosus 2021 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Oral dehydroepiandrosterone vs placebo

• Interventions for cutaneous disease in systemic lupus erythematosus 2021 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Oral chloroquine vs placebo

• Interventions for cutaneous disease in systemic lupus erythematosus 2021 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Oral methotrexate vs placebo

• Interventions for cutaneous disease in systemic lupus erythematosus 2021 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Moisturisers vs vehicle, placebo or no moisturiser

• Emollients and moisturisers for eczema 2017 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 300 participants
  Low

Selenium (+LT4) vs placebo (+LT4)

The review found no eligible studies for this question.

• Selenium supplementation for Hashimoto's thyroiditis 2013 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Systemic oral acyclovir vs placebo or no treatment

The review found no eligible studies for this question.

• Acyclovir for treating primary herpetic gingivostomatitis 2008 · Cochrane All outcomes
  No data were available in either included study (Amir 1997b; Ducoulombier 1988).
  Studies not reported
  No studies found

Serenoa repens vs placebo or no intervention

Serenoa repens showed no clear difference in quality of lifeMeasured by IPSS‐QoL score (range 0 to 6) compared with placebo or no intervention (high certainty).

• Serenoa repens for the treatment of lower urinary tract symptoms due to benign prostatic enlargement 2023 · Cochrane Headline outcomes only
  no estimate extracted
  5 studies · 1001 participants
  High

Serenoa repens in combination with other phytotherapy vs placebo or no intervention

• Serenoa repens for the treatment of lower urinary tract symptoms due to benign prostatic enlargement 2023 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 265 participants
  Very low

Dornase alfa vs placebo or no dornase alfa treatment

Dornase alfa showed no clear difference in change in quality of life ‐ CFQ‐R respiratory at 1 month compared with placebo or no dornase alfa treatment (low certainty).

• Dornase alfa for cystic fibrosis 2021 · Cochrane Headline outcomes only
  MD 0.84
  19 participants
  Low
• Dornase alfa for cystic fibrosis 2021 · Cochrane Headline outcomes only
  MD 9.78
  19 participants
  Low

Summary of findings table ‐ Cannabis vs placebo

• Cannabis and cannabinoids for symptomatic treatment for people with multiple sclerosis 2022 · Cochrane Headline outcomes only
  no estimate extracted
  8 studies · 1942 participants
  Low

Summary of findings: oral antioxidants (NAC/GSH) vs placebo

• Antioxidant supplementation for lung disease in cystic fibrosis 2019 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 61 participants
  Moderate

L‐ornithine L‐aspartate vs placebo or no intervention

• L‐ornithine L‐aspartate for prevention and treatment of hepatic encephalopathy in people with cirrhosis 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  Very low

Pregabalin vs placebo

• Pregabalin for decreasing pancreatic pain in chronic pancreatitis 2016 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 64 participants
  Moderate

Summary of findings: levodopa vs placebo

• Levodopa for the treatment of restless legs syndrome 2011 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 60 participants
  Moderate