Hyaluronic acid (HA) is a potent humectant capable of binding up to 1,000 times its weight in water. However, its function is governed by thermodynamic principles and the ambient relative humidity. In environments with low humidity—common in air-conditioned offices or dry Australian inland climates—there is insufficient water vapour in the air for the HA molecule to attract. Consequently, if the HA is not paired with occlusive ingredients, it may draw water upwards from the deeper dermis towards the stratum corneum through osmotic pressure. Once this moisture reaches the surface, it can evaporate into the dry air via transepidermal water loss (TEWL), potentially leaving the skin feeling tighter and more dehydrated than before [1], [2].
This phenomenon does not mean HA is 'stealing' moisture in a permanent sense, but rather that it facilitates the movement of water along a concentration gradient. To prevent this, formulation science suggests applying HA to damp skin and immediately sealing it with an occlusive moisturiser containing ceramides or petrolatum. This creates a physical barrier that prevents the 'wicking' effect, ensuring the moisture remains trapped within the skin layers rather than escaping into the atmosphere [3].
Hyaluronic acid is a naturally occurring glycosaminoglycan found within the human extracellular matrix, primarily synthesised by fibroblasts and keratinocytes. In the skin, HA maintains structural integrity and hydration by forming a visco-elastic network that regulates water balance and osmotic pressure. Clinically, different molecular weights of HA—ranging from high-molecular-weight (HMW) to low-molecular-weight (LMW)—interact with the skin barrier differently, with smaller molecules penetrating deeper while larger molecules form a film on the surface [2], [4].
The efficacy of topical HA is highly dependent on the vehicle and the surrounding environment. While it is often marketed as a 'hydration miracle', its chemical nature as a humectant means it is indiscriminately attracted to water molecules. Without a robust lipid barrier or topically applied occlusives to manage the vapour pressure at the skin's surface, HA can inadvertently accelerate the dehydration of the stratum corneum in arid conditions [1], [5].
To mitigate the risk of trans-epidermal water loss in dry climates, we formulated the Cellular Crème with a sophisticated blend of sodium hyaluronate and occlusive agents like shea butter to seal moisture within the skin’s barrier. For those seeking to maintain a supple, youth-preserved complexion, this peptide moisturiser works to replenish the skin’s natural defences while ensuring hydration remains locked where it is needed most.
FAQ
Should I apply hyaluronic acid to dry or damp skin?
Applying HA to damp skin is essential for optimising its performance. By providing a source of external water for the HA to bind to immediately, you minimise the risk of the molecule drawing water from the deeper layers of your dermis. Clinical observations suggest that this technique improves the immediate plumping effect and reduces the risk of post-application dryness in low-humidity environments [3], [5].
Does the molecular weight of HA affect how it reacts to dry air?
Yes, molecular weight significantly influences the interaction. High-molecular-weight (HMW) HA sits on the skin surface, forming a film that is more susceptible to environmental humidity changes. Low-molecular-weight (LMW) HA can penetrate the stratum corneum, potentially providing deeper hydration but also posing a greater risk of inflammatory responses if the skin barrier is compromised. Both types require an occlusive seal to prevent TEWL in dry climates [2], [4].
Is hyaluronic acid suitable for the Australian climate?
HA is highly effective in Australia, provided the application method is adapted to the local environment. In humid coastal regions (like Brisbane or Sydney in summer), HA can pull moisture from the air effectively. However, in dry southern winters or arid central regions, it must be used cautiously with a thick moisturiser to ensure it doesn't exacerbate dryness through increased transepidermal water loss [1], [3].
References:
[1] Papakonstantinou E, et al. Hyaluronic acid: A key molecule in skin aging. Dermato-Endocrinology. 2012;4(3):253-258. doi:10.4161/derm.21923
[2] Pavicic T, et al. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. Journal of Drugs in Dermatology. 2011;10(9):990-1000.
[3] Draelos ZD. The science behind skin care: Moisturisers. Journal of Cosmetic Dermatology. 2018;17(2):138-144. doi:10.1111/jocd.12490
[4] Jegasothy SM, et al. Efficacy of a New Topical Nano-hyaluronic Acid in Humans. The Journal of Clinical and Aesthetic Dermatology. 2014;7(3):27-29.
[5] Sethi A, et al. Moisturizers: The Slippery Road. Indian Journal of Dermatology. 2016;61(3):279-287. doi:10.4103/0019-5154.182427
