Taneesa Williamson Here’s why understanding the difference between low and high molecular weight HA is crucial for achieving desired skin results.
Hyaluronic Acid (HA) is often touted as the holy grail of skincare ingredients, renowned for its hydrating properties and ability to give skin a plump, youthful appearance. However, not all clients see the transformative effects they expect. The secret lies in the molecular weight of the HA being used.
1. Penetration Power: The Molecular Weight Matters
The effectiveness of HA largely depends on its molecular weight. High molecular weight HA (HMW-HA) has larger molecules that sit on the skin’s surface, forming a hydrating barrier. This is ideal for immediate surface hydration, making the skin feel softer and smoother. However, it may not penetrate deeply enough to address underlying hydration needs or stimulate collagen production.
In contrast, low molecular weight HA (LMW-HA) has smaller molecules that can penetrate deeper into the skin layers. This deeper absorption allows it to hydrate from within, improve skin elasticity, and reduce fine lines more effectively. If your clients are not seeing significant changes, it might be due to using HMW-HA which is limited to surface-level hydration.
2. Moisture Retention vs. Lasting Hydration
While HMW-HA excels at drawing moisture to the skin’s surface, it might not provide long-lasting hydration. This can be particularly problematic for clients with dry or aging skin that requires moisture deep within the dermis. HMW-HA can give an initial plumping effect, but it doesn’t always sustain the hydration needed for long-term skin health.
LMW-HA, on the other hand, ensures that the deeper layers of the skin are adequately hydrated, contributing to long-term improvements in skin texture and appearance. By reaching deeper layers, LMW-HA can help maintain skin hydration over time, which is essential for clients looking for more than just a temporary fix.
3. Skin Barrier Function and Irritation
The skin barrier’s health is crucial for overall skin appearance and function. HMW-HA, while excellent for surface hydration, can sometimes disrupt the skin barrier if not formulated correctly, leading to irritation and dryness in some clients. This can counteract its hydrating benefits, leaving the skin in a worse condition than before.
LMW-HA, with its ability to penetrate deeper, tends to be more effective in reinforcing the skin barrier and improving its resilience. This helps in preventing moisture loss and protecting the skin from environmental stressors. For clients with sensitive skin, LMW-HA is often a better choice as it is less likely to cause surface irritation and more likely to provide the desired results without adverse effects.
For clients not experiencing the benefits of HA, the issue might lie in the molecular weight of the HA being used. High molecular weight HA offers surface hydration but may not penetrate deeply enough for lasting change, while low molecular weight HA provides deeper, more enduring hydration and skin improvement.
Our favourite Hyaluronic Acid serums:
Synergie Skin HylaVive Serum – Boost moisture levels and regenerate the skin with this ultimate hydrating serum. Formulated with three types of hyaluronic acid, penetrating multiple layers of the skin, to hydrate and firm your skin while smoothing the appearance of fine lines. 
Medik8 Hydra B5 Intense – Natural Moisturising Factors (NMF) and superfood antioxidants work with multi-weight hyaluronic acid to flood the skin with moisture so that the look of crepiness and dehydration lines are drastically improved. 
PCA Hyaluronic Acid Boosting Serum – Plump the appearance of skin through increased hydration with this hyaluronic acid formulation. This smoothing blend provides deep, long lasting hydration with three types of Hyaluronic Acid and the added benefits of ceramides and niacinamide. 
Jan Marini Hyla 3D Serum – Hyla3D’s patented combination of 5 advanced Hyaluronic Acid (HA) supporting technologies provides lasting HA to the skin in a weightless serum – perfect for combining into any skin care routine on any skin type. In addition, multiple advanced technologies unique to Hyla3D Face Serum further support HA, elastin and overall skin quality. 
Cosmedix Surge – This ultra-dewy Hyaluronic Acid Booster deeply moisturizes dry, dehydrated skin with a specialized blend of three forms of hyaluronic acid (1.5%), niacinamide and kiwi fruit water.
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