What do systematic reviews say?

Zinc vs placebo

It is very uncertain whether zinc supplements (zinc sulphate, zinc gluconate, zinc picolinate,… changes adverse events compared with placebo (very low certainty).

• Interventions for managing taste disturbances 2017 · Cochrane All outcomes

  12 to 18 weeks
  RR 5.20 [0.90, 30.19]
  3 studies · 335 participants
  Very low

Chlorine dioxide + zinc mouthwash vs Placebo mouthwash

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  2 weeks
  Adverse events reported by Borden 2002 were not related to the interventions.
  1 study · 41 participants
  GRADE not reported

Chlorhexidine + zinc acetate mouthwash vs Placebo mouthwash

The review found no eligible studies for this question.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  mean 3 months
  Adverse events: listed in the Summary of findings table but no data reported. No data were reported for adverse events.
  0 studies
  No studies found

Zinc chloride + sodium fluoride dentifrice vs Sodium fluoride (control) toothpaste

• Interventions for managing halitosis 2019 · Cochrane All outcomes
  Payne 2011 reported 19 non-oral and 12 oral adverse effects. The oral effects were tingling sensation in lips, dry mouth or sore gums.
  1 study
  GRADE not reported

Cetylpyridinium chloride + essential oils + chlorine dioxide + zinc mouthrinse (Breath Rx) vs placebo

• Mouthrinses for the treatment of halitosis 2008 · Cochrane All outcomes

  4 weeks
  Borden 2002: 13 adverse events were reported in the trial, but the investigators concluded that none were likely to be related to product usage.
  1 study
  GRADE not reported

0.05% chlorhexidine + 0.05% cetylpyridinium chloride + 0.14% zinc lactate mouthrinse vs Placebo mouthwash

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  mean 2 weeks
  Adverse events (Table 6). Risk with placebo mouthwash: None reported. Risk with halita mouthwash: tongue staining was seen in patients who gargled, rather than rinsed. 40 participants (1 RCT). Certainty: VERY LOW.
  1 study · 40 participants
  Very low

0.05% chlorhexidine + 0.05% cetylpyridinium chloride + 0.14% zinc lactate mouthrinse vs placebo

• Mouthrinses for the treatment of halitosis 2008 · Cochrane All outcomes

  2 weeks
  Winkel 2003: significantly more tongue staining (P < 0.001) and tooth staining (P < 0.002) were noted with the chlorhexidine + cetylpyridinium chloride + zinc lactate mouthrinse than with placebo.
  1 study · 40 participants
  GRADE not reported

Cetylpyridinium chloride mouthwash vs Chlorhexidine + zinc mouthwash

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  2 weeks
  Adverse events reported by Borden 2002 were not related to the interventions.
  1 study · 44 participants
  GRADE not reported