Why I’m Not Impressed by Hyaluronic Acid

If hyaluronic acid were at school, it would definitely be in the cool crowd. It’s everywhere. But I think it’s thoroughly over-rated and doesn’t really deserve to be included in a discussion around active ingredients at all - the acid part means it’s often miscategorised this way, which is thoroughly misleading. The fact that it’s being sold at a £250+ price tag by some brands is literally insane to me. 

What does a hyaluronic acid serum do?

Don’t get me wrong - as a moisturiser, it’s perfectly useful. It does an adequate job as a humectant and it’s very safe at that. As an endogenous molecule, it’s something our bodies recognise and therefore you’re not going to react to it. But it is not a line filler, volumiser or otherwise powerful anti-aging ingredient unless it’s in a syringe.  

It all comes down to size - it really does matter. Hyaluronic acid is categorised by how small the molecules are. And they can range from the order of large MW hyaluronic acid down to ultra-low MW hyaluronic acid. But these still fall far short of the 500 dalton rule, which governs what can penetrate our highly effective skin barrier, the epidermis. And we probably wouldn’t want these small molecules to penetrate because they are potentially mediators of inflammation.

So let’s be realistic about our expectations around hyaluronic acid - that’s the secret to skin happiness, after all. Decent moisturiser? -Yes, absolutely. Especially if you live somewhere humid. Game-changing age reversing powers?  I think not.