What a 1/5 rating means
On the comedogenic scale, a 1 sits at the safe end of the scale — clogging is unlikely for most people. That places Lithium Stearate in the range most people, including many with acne-prone skin, tolerate well.
One thing the number cannot tell you is concentration. Ingredients are listed in descending order, so Lithium Stearate near the end of a label is present in tiny amounts and matters far less than the same ingredient near the top.
About Lithium Stearate
It is a thickener that controls how a product flows and feels. A metallic stearate soap used as a thickener and gellant in anhydrous sticks and pencils. Rated 1, in line with the other stearate salts such as magnesium stearate.
Lithium Stearate in makeup and skincare
It sets the consistency of gels, liquid foundations, and serums. Its irritancy is rated separately at 0/5, which is low.
If you deal with fungal acne (malassezia folliculitis) rather than ordinary clogged pores, note that Lithium Stearate is among the fatty-acid or ester-type ingredients that community sources commonly avoid — a separate concern from its comedogenic score, and one with weaker evidence behind it.