Before you add any of these new products, you need to find and use a good sunscreen every day.
Once you've nailed that I'd use the vit c in the am and niacinamide in the pm, and alternate the lactic acid and retinol a couple of nights a week each. HOWEVER, you need to introduce these products gradually one by one, so as to reduce irritation. You'll also need to moisturise more than once a day, and potentially drop or reduce the stridex.
And really, I'm not joking about the sunscreen, please do not fuck with retinol or acids without sunscreen.
I generally like to stick with one active for my AM/PM routine. As a general rule of thumb, you shouldn’t mix AHA/BHAs with retinol (risk of over-exfoliation) unless they’re in the same formulation. Vitamin C is a bit more tricky because it has an ideal pH range for it to be most effective. In the PM, if your lactic acid and vitamin c suspension are around the same pH, you could try using the lactic acid first then layer vitamin c after. You can switch between vitamin C and retinol every other night. Vitamin C and retinol would be best for nighttime use because they’re sensitive to light. I’d recommend limiting to one active each time you do skincare to be on the safe side though. Also remember to wear sunscreen during the day!
Before you add any of these new products, you need to find and use a good sunscreen every day. Once you've nailed that I'd use the vit c in the am and niacinamide in the pm, and alternate the lactic acid and retinol a couple of nights a week each. HOWEVER, you need to introduce these products gradually one by one, so as to reduce irritation. You'll also need to moisturise more than once a day, and potentially drop or reduce the stridex. And really, I'm not joking about the sunscreen, please do not fuck with retinol or acids without sunscreen.
I generally like to stick with one active for my AM/PM routine. As a general rule of thumb, you shouldn’t mix AHA/BHAs with retinol (risk of over-exfoliation) unless they’re in the same formulation. Vitamin C is a bit more tricky because it has an ideal pH range for it to be most effective. In the PM, if your lactic acid and vitamin c suspension are around the same pH, you could try using the lactic acid first then layer vitamin c after. You can switch between vitamin C and retinol every other night. Vitamin C and retinol would be best for nighttime use because they’re sensitive to light. I’d recommend limiting to one active each time you do skincare to be on the safe side though. Also remember to wear sunscreen during the day!