QUICK ANSWER: "Yes"
The Aquila Baritone gCEA strings AQ23U. Baritone Conversion Strings Calibrated to gCEA Tuning.
The standard baritone ukulele strings are lower in pitch than the standard ukulele tuning. They are tuned to DGBE (the same as the top four strings of a guitar). They also differ from the standard ukulele as they are not in re-entrant tuning i.e.. the strings go from low to high.
The Scale length of the baritone is longer than that of a Tenor Ukulele. The strings are pulled to a lower tension and produce notes lower in pitch then regular ukulele.
So If you attempt to tune your standard baritone strings up in pitch to gCEA by tightening them up you will most likely start snapping strings and/or pull your bridge off the top of your ukulele.
The Baritone to Tenor tuning Conversion Strings made by Aquila are made specifically to produce notes of gCEA at the correct tension AT THE baritone scale length. From the treble side to bass side / 1st string to 4th string are about 025 031 038 027 in thousandths of an inch.
The strings are all plain Nylgut material with no wound stings. Nylgut is a new formulation of polymerized plastic mixed with additives and patented by Aquila.
THE ANSWER TO A BARITONE TUNED TO GCEA IS
You need the right strings. Aquila Baritone gCEA strings CODE:AQ23U Baritone Conversion Strings Calibrated to gCEA Tuning.