Bulking agents in skincare

Bulking agents are ingredients that can absorb and retain water. In skincare, they help bind moisture in the upper layer of skin and keep it supple. The term originally comes from pharmacy, where bulking agents swell in the digestive tract. In cosmetics, it refers to water-binding substances that improve the skin's moisture content and support its protective function.

How swelling agents work

The outermost layer of skin, the stratum corneum, functions like a natural protective film. It contains lipids, proteins, and humectants that together form the skin barrier. When this barrier is weakened, the skin loses water and becomes dry or rough. Bulking agents counteract this by absorbing moisture, storing it in the tissue, and thus maintaining the skin's elasticity and firmness.

Typical examples of swellable ingredients

• Hyaluronic acid – it is considered one of the strongest moisture reservoirs. A single molecule can bind many times its own weight in water, thus ensuring plumper skin ( skinceuticals.de ).
• Glycerin – A classic humectant that attracts water from the environment and binds it in the skin. It strengthens the skin barrier and prevents dryness ( larocheposay.de ).
• Urea (urea) – a component of the natural moisturizing factor (NMF), improves skin hydration and relieves feelings of tightness ( eucerin.de ).
• Aloe Vera – Plant polysaccharides have a water-binding and soothing effect, they support the regeneration of dry skin ( nivea.de ).

Effect on the skin barrier

Bulking agents not only improve hydration but also stabilize the lipid structure of the stratum corneum. This reduces transepidermal water loss (TEWL), which in turn protects the skin from environmental influences and micro-irritations. Studies show that a combination of water-binding and lipid-strengthening active ingredients can significantly increase skin hydration ( fokus.swiss ).

Application in care products

Skincare products with swelling ingredients are particularly suitable for dry, sensitive, or mature skin. They support daily hydration and improve suppleness. Regular use is crucial, as the effect diminishes if the skin is not moisturized for an extended period.

In combination with NATURFACTOR® care

NATURFACTOR® Porcelain Skin Serum contains intensely moisturizing active ingredients such as hyaluronic acid and bioactive amino acids, which act as natural swelling agents. The formula combines these with regenerating lipids and peptides to strengthen the skin barrier and retain moisture for long-lasting effect.

Conclusion

Bulking agents are essential for hydrated, smooth, and resilient skin. They retain moisture in the stratum corneum, reduce dryness, and ensure a visibly fresher complexion. In combination with barrier-strengthening ingredients, they form the basis of healthy, well-cared-for skin.

Sources

1. Skinceuticals – Hyaluronic acid in skincare
2. La Roche-Posay – Glycerin in skincare products
3. Eucerin – Urea as a moisturizer
4. NIVEA – Aloe Vera in skincare
5. FOCUS – Science on Hyaluronic Acid

Tags: swelling agents, moisture reservoir, skin barrier, hyaluronic acid, glycerin, natural skincare