In this month’s Q&A, Susan asked, I’m wondering whether humectants are fully interchangeable, the same way that hydrolyzed proteins seem to be. Specifically, I’m looking at a Lotioncrafter formulation (Time Defy Facial Serum) which calls for butylene glycol but I don’t have any. I do have vegetable glycerin, honeyquat, sodium lactate, and propanediol 1-3. I’m hoping…
