Hello, both formulas can be mixed but formula 2 may have problems with skin irritation because both Complex Salicylic Acid (Powder, Water-Soluble) 5% 5 Willow Bark Extract 5% can irritate the skin if used at such high rates. That's enough. The two formulas are similar. It is recommended that they be combined into one formula. would be better
Hello, the ingredients when mixed together must be 100%, not add more than 100% if there are active substances that want to be added to Aloe Vera Gel 20% also apply. Aloe Vera Gel 80% active ingredients 20%