REF-962 · Gavel et al., 2024 · Sports Medicine - Open, Vol. · Paper · PubMed

How Cool is That? The Effects of Menthol Mouth Rinsing on Exercise Capacity and Performance: A Systematic Review and Meta-analysis

A-fairly strong evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

This systematic review and meta-analysis asked whether menthol (MEN) mouth rinsing (MR) changes exercise capacity and performance.

The authors searched three databases, pooled the data with three-level meta-analyses, and ran meta-regressions on mean VO2peak, swilling duration, menthol concentration, how many swills an experiment used, which control solution was used, mean environmental temperature in the exercise tests, and exercise type. Ten studies reported enough to be included.

Rinsing with menthol produced no significant change in capacity or performance (SMD = 0.12, p = 0.23; 95% CI -0.08, 0.31; I2 = 0%), and none of the meta-regressions found a significant influence. The authors conclude that MEN MR gave no significant improvement in overall exercise capacity and performance, although people doing endurance exercise may see benefits.

Participants

Ten menthol mouth-rinse studies. Participant numbers, sex and training level are not given in the abstract; mean VO2peak was tested as a moderator.

Protocol

Three databases searched; articles screened by inclusion/exclusion criteria.
Three-level meta-analyses for the overall effect of MEN MR on exercise capacity and performance.
Moderators tested by meta-regression: 1) mean VO2peak, 2) how long the rinse was swilled, 3) the menthol concentration of the rinse, 4) how many swills one experiment used, 5) the control solution (non-flavoured neutral, or flavoured sweetened, non-caloric), 6) mean environmental temperature during the exercise tests, 7) exercise type.

Key Results

Overall: menthol rinsing did not significantly change capacity or performance (SMD = 0.12, p = 0.23; 95% CI -0.08, 0.31; I2 = 0%).
ModeratorEstimate95% CIp
VO2peak0.03-0.03, 0.090.27
Swilling duration (5 vs. 10 s)0.00-0.41, 0.411.0
Menthol concentration (low [0.01%] vs. high [0.1%])-0.08-0.49, 0.320.67
Number of swills0.02-0.05, 0.090.56
Control solution (non-flavoured vs. flavoured)0.12-0.30, 0.550.55
Mean room temperature during exercise tests0.01-0.02, 0.040.62
Authors' conclusion: no significant improvement overall, "though those involved in endurance exercise may see benefits". The abstract gives no effect size for endurance exercise.

Practical Application

Across ten studies (systematic review and three-level meta-analysis), rinsing the mouth with menthol did not significantly change exercise capacity or performance (SMD = 0.12, p = 0.23), and neither the concentration (0.01% vs. 0.1%), the swill duration (5 vs. 10 s), the number of swills nor the room temperature changed that. To "will a menthol mouth rinse make me faster on a hot day?": on the pooled evidence, not reliably; the authors leave open a benefit in endurance exercise without giving a number for it.
There is no measured dose-response: a stronger solution, a longer swill or more swills did not produce a larger effect. Any specific rinse recipe is therefore practice, not a tested optimum.
Room temperature did not moderate the effect, so this abstract does not support "it only works in the heat" for the rinse.
Inference, not tested here: a rinse may still make an athlete feel cooler; perception is not an outcome in this abstract (thermal sensation by any route is in REF-961).
Not from this paper: the routes compared in the heat are in REF-964; the base's protocol and safety caveats are in SYNTH-25.

Limitations

Ten studies; participant numbers and trial designs are not in the abstract.
The possible endurance benefit is the authors' qualification, stated without an effect size.
The abstract reports no thermal sensation, body temperature, sweating or adverse-event outcome, so it says nothing about safety.
Meta-regressions over ten studies have little power to detect a moderator.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

systematic review and meta-analysis of ten studies; trial sizes are not given in the abstract