Best for makeup application afterwards. Might try Anthelios ultra-fluid SPF 50+ facial sunscreen on non-makeup days ($$).

3 times/week alternation with retinol.

Used 1/week when I see more texture or soon to be breakouts. Then I resume with Vitamin C and retinoil aternation for the following days.
(Strawberry Smooth BHA + AHA Salicylic Acid Serum from Glow Recipe sometime used instead, more $$)

Not used with Vitamin C serum (which already has 2% HA).
Order of use depending on the product :
- Before retinoil
- After lactic acid
- Before overnight mask

3 times/week alternation with vitamin C.

More $$ but only used when I need to feel extra glowy the next day for an event or else. Replaces my chemical exfoliant for that week.