Effect of caffeine on the vocal folds: a pilot study

J Laryngol Otol. 1999 Apr;113(4):341-5. doi: 10.1017/s0022215100143920.


Caffeine is considered to be a dehydrating agent with detrimental effects on the quality of voice of persons ingesting it. This has led medical personnel dealing with voice disorders, especially in the case of professional voice users, to give advice against the use of caffeine. Yet this is an anecdotal truth as an extensive Medline literature search did not reveal any scientific evidence of caffeine being proven to have adverse effects on the vocal folds. We, therefore, initiated this pilot study to ascertain the connection between caffeine and voice quality on a laboratory basis. Two hundred and fifty mg of caffeine were provided to eight volunteers in tablet form, and blood levels along with laryngograph readings were recorded to document the changes produced. Analysing the irregularities of frequencies in a) free speech b) a reading passage and c) singing 'Happy Birthday', substantial changes were seen to authenticate the fact that caffeine does produce alterations in voice quality but these alterations have considerable intra-subject variability. A full study with wider parameters is to be performed on this subject as we consider it to be of importance in the management of voice disorders.

MeSH terms

  • Adult
  • Caffeine / pharmacology*
  • Dehydration / chemically induced*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Phosphodiesterase Inhibitors / pharmacology*
  • Pilot Projects
  • Vocal Cords / drug effects*
  • Voice Quality / drug effects


  • Phosphodiesterase Inhibitors
  • Caffeine