Sublingual caffeine delivery via oral spray does not accelerate blood caffeine increase compared to ingestion of caffeinated beverages.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 40000478 · doi:10.1007/s00421-025-05735-z
What was done
Fourteen adults (6 males, 8 females; 24 ± 3 years, 69.9 ± 9.3 kg) underwent a 16-hour caffeine fast, consumed a standardized breakfast, and then received 60 mg of caffeine through three different delivery formats in a randomized crossover design: mouth spray (sublingual), coffee, or an energy drink. Serum caffeine levels were measured over the subsequent 90 minutes, and cognitive function was evaluated at approximately 30 and 90 minutes post-dose.
What was found
Serum caffeine increased from baseline in all three groups (p < 0.0001), but concentrations were not significantly different between mouth spray, coffee, and energy drink at any timepoint (p = 0.06). There were no significant differences across mouth spray, coffee, and energy drink for caffeine area under the curve (61 [54–73], 82 [51–119], and 68 [43–78] min*mg/L, respectively; p = 0.22) or peak concentration (1.6 [1.2–1.8], 1.9 [1.4–2.4], and 1.2 [0.8–3.0] mg/L, respectively; p = 0.19). For the mouth spray, serum caffeine was higher than baseline from 10 to 90 min (p < 0.03) but not at 5 min (p = 0.50), peaking at 90 min. Cognitive test performance did not differ by delivery method (p > 0.22).
Why it matters
Sublingual caffeine sprays do not provide faster systemic absorption or faster cognitive benefits compared to standard caffeinated beverages.
Limits
The sample size was very small (n = 14) and limited to young healthy adults. The study tested only a single 60 mg dose of caffeine and tracked outcomes for a relatively short 90-minute window.
Cited by
- supports Caffeine concentrations in the body peak approximately 30 minutes after consumption.