In the last post I talked about how to read a formula and it was based off a brand who claimed to have a potent hyaluronic acid serum and what we discovered was that its just a regular bare minimum formula and certainly not worth $300USD. In that post I also said I would do a HA 101 to basically just talk about what it is, how it works, what types of HA are available, the maximum percentage each ingredient will be used in a cosmetic product before it starts affecting your skin negatively, and all about molecular weights and what that means.
Starting off with, what is hyaluronic acid?
Hyaluronic Acid is a natural occurring molecule that is found in the human body. It works by retaining moisture. It is found all over the skin, organs and just about everywhere else too. As you age your skin lacks the ability to retain moisture which is called “Transepidermal water loss”. That is where HA plays a huge role in keeping the skin hydrated.
You may have heard... Correction, you have definitely heard the line “Hyaluronic Acid holds 1000x its weight in moisture”. That is most certainly true. It is a humectant which means it is going to draw moisture from the atmosphere and trap it in your skin, which gives you that instant plumped look. The downfall with hyaluronic acid is that in majority of our climates (ie dry, wintery climates), there is a lack of moisture in the air. So where does HA draw the moisture? Well, it actually draws the moisture up from the dermis to the epidermis. This gives you that plumped up look too, but the problem is that HA doesn’t supply the dermis back with the moisture it stole. This is why people always suggest to follow the usage of hyaluronic acid with a moisturizer that has a healthy occlusive such as ceramides. Ceramides create a protective barrier where your skin will not lose any moisture.
The good thing about HA being a humectant is that anything that you put on after it will be pulled deeper into the skin. You can think of hyaluronic acid as a delivery system or, in reality, the “vehicle” of the product. Currently in this day and age, everyone always wants everything to “penetrate into the dermis!” and if it doesn’t they’ll scratch it off as a “bad” product. Not everything needs to get to your dermis and not everything SHOULD get to your dermis. Reliable and clinical brands develop products that are trialed to do what they’re suppose to do and quite frankly, almost all of your products - despite what you think or what someone told you, are not penetrating the dermis... and that’s completely fine. Anything that is able to get into your dermis - or even the bloodstream, is regulated and likely a medical prescription.
Moving onto the forms of hyaluronic acid... This is a bit more tricky because there are a few different ingredients that are commonly used in a hyaluronic acid serum. Look for: hyaluronic acid, sodium hyaluronate, and hydrolyzed sodium hyaluronate. The part that get’s trickier is the molecular weight... There are 3 common molecular weights for HA: high molecular weight, mid-molecular weight, and low molecular weight. Each molecular weight varies in actual molecular weight and that then penetrates at different depths. For an example, you may see a brand like Nioid (by deciem) say their Multi-Molecular Hyaluronic Complex has 15 different weights and think “hows that possible there is only 3... high, mid & low” but in actuality, each category of weight has a “sub-category” of additional weights. For a full detailed post by NayaGlow on molecular weights, you can click here. Scroll down to the table that outlines molecular weights in Dalton, so you can see exactly the variable weights.
So now you know what it is, what its function is, some forms & their weights, but now we need to get into the percentage that is used in a formula to make it effective without adverse effects. Starting with Hyaluronic Acid, this is usually used at a 0.25%-2.5%. The recommended minimum to be effective is 1%. Next is sodium hyaluronate, this is the sodium salt of hyaluronic acid. It is commonly used in serums labelled hyaluronic acid because it is a more stabilized version that is less likely to oxidize. Sodium Hyaluronate is used at a 1-2% solution and should not be used in a solution higher than 4%. The reason behind that is because it is a salt and too much salt will absorb all the water - in turn, makes you dry. Then there is hydrolyzed sodium hyaluronate, this is sometimes referred to as MicroHA or MiniHA because it is a very small sized molecule that is able to penetrate the deepest out of them all. Hydrolyzed sodium hyaluronate (HSH) is a chemically “chopped” version of sodium hyaluronate. It has a molecular weight of 10 kDa... To put that into perspective, “regular” hyaluronic acid has a weight of 0.5-2 million Da.Unfortunately, I cannot find any details online about the recommended or common amount found in a product.
Alright, now as for recommendations... I won’t list actual products because there are way too many, but if you are eyeballing multiple hyaluronic acid serum and want to know which one to go for, look for a serum that has multi-molecular weights (sometimes written MMW or MMHW) and have multiple forms of hyaluronic acid in it. The more weights and more forms of hyaluronic acid, the more expensive it becomes. Remember, single ingredient at a single weight is still perfectly fine and will still be effective.