Product application: are actives cumulative?

And yet another one!

As you can see, once I found you guys my Beauty Brain started spinning and now I just can't stop coming up with these kind of stoner questions.

So, if in my routine I apply to steps with the same active ingredient, do I increase their effectiveness? Are actives cumulative, or the only way to obtain the proved results of a given percentage is to have that percentage in one product?

Here's why I'm asking: I recently purchased some samples from Paula's Choice products. I've read that, for example for niacinamide, the sweet spot is 4% in a formulation. However, after looking at the ingredient list of the samples I purchased, I don't believe the amount in either is even close:

I quite like both products, but I it could very well be the siliconey feeling. I thought that maybe their power combined was useful, but is it really? I don't want to support with my money half-way there science.

And now some stories from abroad. In Spain, L'Oreal ads for serums say "now with Gene Science". Obviously they couldn't say genetics (gene science must be to genetics what astrology is to astronomy). Do you get such absurd ads in the US as well?



  • There are PLENTY of absurd ads here in the US as well!

    I'm not quite sure how to answer your question about "are actives cumulative?" If you haven't applied enough of an active, then a second or third application can be beneficial. But sometimes too much of an ingredient can be a bad thing. 

    I'm not familiar with the formulas of the Paula's products you mentioned so I don't know the exact concentration of niacinamide. 
  • Sure, one wouldn't want to apply layer after layer of a retinoid. But it's good to know that, within safe limits, it can be beneficial to get a couple applications of the same active. 
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

In this Discussion