AMA Manual of Style - Stacy L. Christiansen, Cheryl Iverson 2020

Capitalization After a Greek Letter
Greek Letters

In titles, subtitles (except in references), headings, and at the beginning of sentences, the first non-Greek letter after a lowercase Greek letter should be capitalized.

β-Blockers help control heart rate and are also used in the treatment of abnormal heart rhythms.

Do not capitalize the Greek letter, unless the word normally includes a Greek capital letter. In that case, the first non-Greek letter after the capital Greek letter should be lowercase.

Β-Hemolytic streptococci are bacteria that can destroy red blood cells and cause a variety of diseases.

Δ-9-tetrahydrocannabinol administered intravenously to marijuana smokers disappeared from the blood plasma with a half-life of 28 hours compared with 57 hours for nonusers of marijuana.

For hyphenation in words that contain Greek letters, consult 8.3.1.8, Hyphen, Special Combinations.