It seems like we’re always reading product reviews. And while they’re useful, it’s important to keep in mind that they can only go so far. Check out my pros and cons:
http://www.futurederm.com/2012/10/18/the-benefits-and-limitations-of-skin-care-product-reviews/
Feel free to add your own to the list! Have fun.
The Triple Helixian 
Is it advantageous detrimental or otherwise significant to combine both Matrixl and Matrixyl 3000 in the same skincare routine (though not necessarily at same time of day). I’m thinking particularly of the down regulation of elastin expression produced by Palmitoyl TetraPeptide 7 but there may be other issues involved also?
Does the down regulation of elastin expression in Matrixyl 3000 inhibit or otherwise impact on the use of other skin actives like RA, AHA, Niacinamide, growth factors etc?
Posted by Robyn Hurren | October 29, 2012, 10:32 pmNo, the use of these peptides doesn’t significantly impact other skin care ingredients because peptides don’t penetrate very well into the skin, if at all. The few studies documenting peptide efficacy were mostly done in vitro. While they may be beneficial, I wouldn’t rely on them. I’ll be doing a massive peptide overview in the future, though it’ll be a while before it’s posted. I’m just too busy! 😦
Posted by John | October 30, 2012, 11:38 amThankyou John, I will eagerly await your analysis of peptide efficacy.
May I further ask if there is a resource which I can check for the length of time various ingredients – tretinoin, AHA, antioxidants etc, are active at their various sites of operation after penetration, so I can better determine how to space out the application of each because my skin will not accept multiple layers of products and must be cleansed between applications.
Posted by Robyn Hurren | October 30, 2012, 11:07 pmYou’re welcome. I don’t know of any resource that lists everything. And there isn’t an absolute length of time for products. These recommendations that I make of waiting “x” amount of minutes are all just estimations.
If you cannot use multiple layers of products, then try looking for products that are as multi-purpose as possible, for example a sunscreen with antioxidants, and perhaps a retinol product that includes other ingredients that also benefit the skin. While I do not believe that you’ll be getting as good results as if you were to layer products; hey, you do the best that you can, right?
Happy Halloween!
Posted by John | October 31, 2012, 11:09 am