We often get asked about how long to wait between applying the various products in a daily skin-care routine. Well the answer is that you don’t have to wait at all unless you personally prefer to wait (with the exception of retinol products).
Your skin can actually handle many ingredients at once. As it turns out, skin is capable of handling a lot and 99% of the time, any one product in your routine doesn’t get in the way of the others you may be using. Think of it like your diet: whether you eat all of your vegetables at once or take small bites out of them as you enjoy the other food on your plate. Your body is going to get the same nutritional benefits from the veggies in your meal!
More importantly, it's the order in which the products are applied & how the products are absorbed that matters.
The rule of thumb is thinnest through to thickest (the thickest product being the sunscreen).
For example a serum based product MUST be applied first, followed by a cream based product.
When applying serums apply water based ones first then follow with oil based serums and then creams.
Exceptions to this rule – sometimes two different product textures just aren’t compatible - they don’t play well together - so waiting between applications for them to dry is best.
Finally, it's important to remember that the performance of any products applied is unaffected by the use and application of any other product.