As Wingsfan has siad adding PGA or vodka (tiny amount) will aid in TH.
Juice Components
Flavoring usually about 3- 15%- could be higher or lower depending on the flavor used.
PG enhances flavor, TH and lung hit- water like - many of us believe PG to be a throat irritant.
VG= vapor and can mute flavor- thick
Nicotine- TH, lung hit and our need for nicotine. The MOST important ingredient in regards to TH and lung hit.
Standards in the industry are 80/ 20 or 70/ 30 PG/ VG. Many are moving towards a 50/ 50 ratio as it provides a smoother vape.
You could order the same flavor in 24 mg and if it's too strong mix 18+ 24 to end up with 21 mg.
maybe a B&M nearby where you can test 24 mg:
USA Ecigarette Directory