Have you ever seen a skincare product marketed as having high, low or even multiple weights of hyaluronic acid? If you found yourself wondering what this means (and whether or not it affects the efficacy of the product), you’re not alone.
In this post, I’ll explain what it means for hyaluronic acid to come in different weights, how that affects your skin, and which weights to look for.
How Does Hyaluronic Acid Benefit Skin?
Hyaluronic acid (HA) is one of the most ubiquitous ingredients in skin care. As a refresher, HA is a type of sugar called glucosaminoglycan that is naturally produced by our bodies. Internally, HA helps lubricate joints and other connective tissues. It’s also produced within our skin to keep everything supple and hydrated.
In skin care, HA functions as a humectant. This means it binds water to the skin and helps it hold onto moisture, preventing dehydration through transepidermal water loss. Ultimately, the result is moisturized skin that appears dewy and plump with fewer noticeable fine lines.
What Does It Mean to Have Different “Weights” of Hyaluronic Acid?
When we talk about different “weights” of HA, we’re talking about molecular mass (aka the size of the molecule). HA molecules are broadly categorized as small, medium, or large and are measured in daltons.
But why does this matter? The size of a HA molecule determines how deeply it can be absorbed into the skin. The largest, heaviest molecules will sit on top of the skin and attract water to the outermost layer. Smaller, lighter molecules are able to penetrate through the skin barrier, where they attract water internally to plump skin underneath.
Which Weight of Hyaluronic Acid is Most Effective?
The short answer is, HA is effective regardless of whether it’s low, medium, or high weight. All of these will improve skin elasticity and hydration to some extent. Which weight you use depends on the results you’re looking for. The general consensus is that anything below 50 kilodaltons could potentially irritate the skin while going above 2,000 won’t provide any additional benefit.
The benefit of using medium or high-weight HA is that the results are instant. HA is well-known for its ability to immediately hydrate the skin, giving it a plump and dewy look. This plumping effect helps make fine lines appear less prominent. By preventing water loss, you’re also strengthening your skin barrier which can help with healthier skin aging over time.
Low-weight HA doesn’t have the same immediate, visible effect, but it may be more effective for the reduction of wrinkle depth in the long run. Some studies have also suggested it’s longer-acting, meaning it will help your skin hold on to water for a longer period of time. With low-weight HA, it’s important to use it consistently for at least a month in order to see benefits. If wrinkle reduction is your main goal, you can also check out these other ingredients that promote firmer skin.
Alternatively, if you want the best of both worlds, you can look for products with a blend of molecular weights. One thing to keep in mind is that many companies don’t disclose the exact molecular weight of their HA products, but you can get a sense by feeling the texture of the product. Products with higher-weight molecules have more of a slip since they sit on top of the skin, whereas smaller-weight molecules will give products a more watery texture since they soak in.
The Bottom Line
Is one weight of HA better than the other? The answer is no, HA will improve skin hydration and elasticity regardless of molecule size. Whether you look for a product with low or high-weight HA depends on what your priority is. High-weight molecules have an instant plumping and hydrating effect, providing relief for skin that looks dull or crepey due to dehydration. For more long-lasting benefits, opt for smaller weights. Smaller HA molecules rehydrate skin cells over time, so you won’t get an immediate effect, but they’re better for reducing wrinkle depth in the long run.
Personally, I tend to look for a product with medium to high-weight HA. I’m usually looking for that instant gratification—I want an immediate hit of moisture to bring my skin to life, smooth out the appearance of lines, and help me retain moisture throughout the day. This is what I’ve focused on in my products; my go-to’s are Moisture Infusion Toner and Skin Drink Concentrate Serum.
Finally, while hyaluronic acid is a fantastic ingredient, it’s not the only way to keep skin hydrated! Learn more about all of my favorite ingredients for plumper-looking skin.
Celebrity Esthetician & Skincare Expert
As an esthetician trained in cosmetic chemistry, Renée Rouleau has spent 30 years researching skin, educating her audience, and building an award-winning line of products. Her hands-on experience as an esthetician and trusted skin care expert has created a real-world solution — products that are formulated for nine different types of skin so your face will get exactly what it needs to look and feel its best. Trusted by celebrities, editors, bloggers, and skincare obsessives around the globe, her vast real-world knowledge and constant research are why Marie Claire calls her “the most passionate skin practitioner we know.”