What do systematic reviews say?

STPP chewing gum vs placebo

The review found no eligible studies for this question.

• Home‐based chemically‐induced whitening (bleaching) of teeth in adults 2018 · Cochrane All outcomes
  Not reported
  Studies not reported
  No studies found

Keratinocyte growth factor (KGF; palifermin or repifermin), intravenous vs placebo

• Pharmacological interventions for preventing dry mouth and salivary gland dysfunction following radiotherapy 2017 · Cochrane All outcomes
  No evidence of a difference in reported adverse events across the three trials (nausea, fever, constipation, diarrhoea, headache, fatigue and others)
  3 studies
  GRADE not reported

Beta‐carotene vs placebo

• Antioxidant vitamin and mineral supplements for preventing age‐related macular degeneration 2017 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  High

Vitamin C vs placebo

The review found no eligible studies for this question.

• Antioxidant vitamin and mineral supplements for preventing age‐related macular degeneration 2017 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Multivitamin vs placebo

• Antioxidant vitamin and mineral supplements for preventing age‐related macular degeneration 2017 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  Moderate

Metronidazole vs placebo

• Systemic antibiotics for treating malignant wounds 2017 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 6 participants
  GRADE not reported

Topical treatments (benzydamine hydrochloride oral rinse) vs placebo

• Interventions for treating burning mouth syndrome 2016 · Cochrane All outcomes

  short-term (up to 3 months) · benzydamine hydrochloride
  SoF9. Adverse effects: single study narratively reported that no adverse effects occurred from benzydamine hydrochloride oral rinse; 20 participants (1 RCT); very low.
  1 study · 20 participants
  Very low

Psychological therapies (cognitive therapy) vs placebo

The review found no eligible studies for this question.

• Interventions for treating burning mouth syndrome 2016 · Cochrane All outcomes

  short-term (up to 3 months)
  SoF8: No included study reported the occurrence of adverse events.
  0 studies
  No studies found

Mannitol vs placebo / no treatment

The review found no eligible studies for this question.

• Volume expanders for the prevention of ovarian hyperstimulation syndrome 2016 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Human albumin vs placebo or no treatment

The review found no eligible studies for this question.

• Volume expanders for the prevention of ovarian hyperstimulation syndrome 2016 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

HES vs placebo or no treatment

The review found no eligible studies for this question.

• Volume expanders for the prevention of ovarian hyperstimulation syndrome 2016 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Corticosteroids vs placebo or no treatment

Corticosteroids showed no clear difference in adverse effects compared with placebo or no treatment (moderate certainty).

• Corticosteroids for Bell's palsy (idiopathic facial paralysis) 2016 · Cochrane Headline outcomes only
  RR 1.04 [0.71, 1.51]
  3 studies · 715 participants
  Moderate

Padma 28 vs placebo

It is very uncertain whether padma 28 changes adverse effects compared with placebo (very low certainty).

• Padma 28 for intermittent claudication 2016 · Cochrane Headline outcomes only
  OR 1.09 [0.42, 2.83]
  4 studies · 231 participants
  Very low

Chinese herbal medicines vs placebo

It is very uncertain whether chinese herbal medicine (CHM) changes adverse Effects compared with placebo (very low certainty).

• Chinese herbal medicine for menopausal symptoms 2016 · Cochrane Headline outcomes only
  RR 1.51 [0.69, 3.33]
  7 studies · 705 participants
  Very low

Antibiotics vs placebo, no treatment or therapy of unproven effectiveness

Antibiotics may leads to higher adverse effects compared with placebo, no treatment or therapy of unproven effectiveness (low certainty).

• Antibiotics for otitis media with effusion in children 2016 · Cochrane Headline outcomes only
  RR 2.15 [1.29, 3.6]
  5 studies · 742 participants
  Low

Electrical stimulation vs Placebo / sham solution

Electrical stimulation showed no clear difference in adverse effects compared with placebo or sham treatment (low certainty).

• Electrical stimulation with non‐implanted electrodes for overactive bladder in adults 2016 · Cochrane Headline outcomes only
  RR 1.24 [0.84, 1.83]
  3 studies · 450 participants
  Low

Low‐level laser therapy vs placebo

The review found no eligible studies for this question.

• Interventions for treating burning mouth syndrome 2016 · Cochrane All outcomes

  short-term (up to 3 months)
  SoF6: No included study reported the occurrence of adverse events.
  0 studies
  No studies found

Chronic MND: Cervical/UE Stretch/ROM Exercise + Cervical/UE Strengthening + Dynamic Cervical Stabilization vs sham

The review found no eligible studies for this question.

• Exercises for mechanical neck disorders 2015 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Omega‐3 vs placebo

Omega 3 fatty acids leads to higher adverse effects compared with placebo (high certainty).

• Omega 3 fatty acids for preventing or slowing the progression of age‐related macular degeneration 2015 · Cochrane Headline outcomes only
  RR 1.01
  2 studies · 2343 participants
  High

Diazepam gel vs Placebo gel

Diazepam gel showed no clear difference in adverse effects compared with placebo gel (moderate certainty).

• Anticonvulsant therapy for status epilepticus 2014 · Cochrane Headline outcomes only
  RR 1.5 [0.94, 2.37]
  2 studies · 165 participants
  Moderate