The difficulty is that by applying these ingredients topically, they're not always going to end up in the same place as those in your skin.
For example, ceramides are present in the lipids that form the skin barrier. But when it comes to skincare, it’s tricky to get them to insert themselves into the barrier lipids; so the formulation is key, or they may sit on top of the skin instead.
Hyaluronic acid is found in the deeper epidermis, yet even low weight hyaluronic acid is too large to penetrate the skin easily, and it does it less so than glycerine, for example.
Natural moisturising factors (NMF) are hydrating substances like sodium lactate and PCA. When we apply these to our skin, we're applying them to the outsides of our skin cells. Yet the ones made by our body are found inside those cells. In all honesty, I'm not sure whether it's possible for topically applied NMF to find their way into the skin cells - it may be! However, it does create an extra challenge.
This isn't a bad thing - these ingredients still do good. Ceramides are acting as an emollient and an occlusive to help prevent water loss. Hyaluronic acid and NMF are hydrating the outer layers of the skin, helping to keep the layers below healthy and functioning.
When formulating, it's important to look at how an ingredient behaves topically. Many times, there are alternative ingredients that may give the result we want from skin-identical ingredients; in some cases, they may be more suitable.
The best test is always to try something for a couple of weeks and keep an eye on how your skin behaves. We offer trial sizes so yoy can test our products out before you buy the full size. You can find those on each product page, or here for a full discovery set.