How Deep Do Skin Care Actives Have to Go to Work?

Well, that all depends on what your skin care active is intending to do and how well you can deliver it to its target site and that’s not easy.   I’ve drawn up a slightly wordy and messy diagram to show you where stuff happens in the skin as a way of helping you visualise your products pathway.  For example, a cream that says that it works ‘like botox but without the injection’  would have to reach as far down as the dermis to have any impact on the nerves that control muscle contraction, better still it would need to go way past that, through the subcutis and into the muscle to be really effective.  Of course, this is all possible – deep heat has been making those sorts of claims for years, but it does require a bit of work to get the right dose to the right site at the right time.

skin-model-and-penetration-layers

So, here is a quick breakdown of where you need your actives to get to in order for them to work.

  • Epidermis.  This is easy – just pop it on and as long as your active is stable for long enough and is at the right dose you should get a positive result.   Exfoliants, anti-bacterials, barrier forming, moisturisers, smoothing, anti-inflammatories, anti-oxidants, sunscreens, brightening, whitening, pigmentation evening chemicals and ingredients that calm or warm the system can all work here. Ingredients such as Arnica which help to reduce bruising also get to work in the epidermis by gently stimulating the circulation to help speed up the healing process. Finally ingredients such as hyaluronic acid and most collagen and elastin rich products mostly work here by increasing the hydration which gives the skin a plump, wrinkle-free look for as long as the product remains moist!
  • Dermis. This is quite a bit harder to get to.  Also it is important that products designed to get into the dermis are carefully formulated as the dermis does contain blood vessles and as such can allow chemicals to enter the bloodstream.   Structure building actives such as collagen and elastin need to be in here to ‘re-build’ the skin, ingredients that wish to stimulate hair follicles or help with micro-circulation also have to go into here and so do topical botox actives that work on the nerves.
  • Subcutis.  This is really tricky to get to and is generally accessed via needle by cosmetic surgeons who want to plump up ageing skin to make it look younger (you know that procedure when they inject your butt fat into your face????).  Otherwise here sit your sweat glands and the muscles that contract to give us goose bumps.  You don’t need actives to get down this far to affect sweat glands – the glands can be accessed from the surface of the skin (such as in an anti-perspirant) thankfully!
  • Muscle Layer.  This is where the botox injections get to and where some topical treatments reach in order to help with muscle healing.  More and more cosmetics that want to either ‘work out’ or relax muscles are using something called phonophoresis to help deliver their topical cures to the muscle tissue. Phonophoresis uses ultrasound to ‘push’ products through the skin. This article is pretty easy to read and very interesting.  Cosmetics using this technology have been around for a while now and in some cases it really does work!

So, as you see the average cosmetic doesn’t really have to go very far to be effective which is quite  a relief as when it comes to every-day skin care I’m a big fan of all things shallow.

Take care and love your skin.