Answered By: Marie Ascher Last Updated: Mar 15, 2017 Views: 21
What is the name of the journal? I bet the answer is really, "it depends." Your letter should be written with the conservative number of words required to state your point well.
The AMA Manual of Style does say, "Many journals set limits on the length of letters that will be considered for publication (e.g. 500 words or less and no more than 5 references)."