Liposomes are tiny hollow spheres made of the same type of fat molecules (phospholipids) that form your skin’s own cell membranes. In the Milady Standard Esthetics curriculum, they’re defined as closed lipid bilayer spheres that encapsulate ingredients and target their delivery to specific tissues of the skin. They fall under the broader category of delivery systems, which are chemical systems designed to carry active ingredients to precise layers of the epidermis rather than just sitting on the surface.
How Liposomes Are Built
A liposome is essentially a microscopic bubble. Its wall is made of phospholipids, molecules that have a water-loving (hydrophilic) head and a fat-loving (hydrophobic) tail. When these molecules are mixed in water, they spontaneously arrange themselves into a double layer: the hydrophilic heads face outward toward the surrounding water, while the hydrophobic tails tuck inward, facing each other. This creates a sealed sphere with a water-filled core inside.
Some liposomes have just one of these double-layered walls, while others have multiple layers stacked like the rings of an onion, each separated by a thin layer of water. This layered structure is what makes liposomes so versatile. Water-soluble ingredients (like vitamin C or hyaluronic acid) can be stored in the aqueous core, while oil-soluble ingredients (like retinol or vitamin E) can be tucked between the fatty tails in the bilayer wall itself. A single liposome can carry both types of ingredients at once.
Why Liposomes Matter in Skincare
The outermost layer of your skin, the stratum corneum, is designed to keep things out. Most skincare ingredients applied to the surface have a hard time getting past this barrier on their own. Liposomes solve this problem through several routes. Research published in the International Journal of Nanomedicine found that liposomes can penetrate through hair follicle openings, which offer a larger pathway that bypasses the stratum corneum’s barrier entirely. They can also work their way between and even through the cells of the outer skin layer, disrupting the tightly packed lipid structure just enough to allow the active ingredients to pass into the deeper, living layers of the epidermis and dermis.
Once liposomes reach their target depth, they gradually break apart and release their contents. This controlled release is a key advantage over simply applying a raw active ingredient to the skin. Instead of delivering a large dose all at once (which can cause irritation), the liposome parcels out its payload over time.
Ingredients Commonly Delivered by Liposomes
Liposomal encapsulation is used across a wide range of professional and retail skincare products. Some of the most common pairings include:
- Vitamins C and E: Antioxidants that are notoriously unstable when exposed to air and light. Encapsulating them in liposomes protects them from breaking down before they reach the skin.
- Retinol: A potent anti-aging ingredient that frequently causes surface irritation. Liposomal delivery reduces that irritation by releasing retinol gradually into deeper skin layers rather than flooding the surface.
- Hyaluronic acid and glycerin: Hydrating agents that benefit from liposomal delivery because the encapsulation helps them penetrate more effectively and retain moisture for longer.
- Peptides: Small protein fragments used in anti-aging formulations to stimulate collagen production. Liposomes help ferry these molecules past the skin barrier, where they can interact with living cells.
- UV filters: Sunscreen actives encapsulated in liposomes gain improved stability, helping them remain effective longer on the skin.
Benefits Over Traditional Formulations
Liposomal delivery offers four distinct advantages over simply mixing an active ingredient into a cream or serum. First, stability: many vitamins and antioxidants degrade when exposed to heat, light, or air. The liposome shell acts as a protective barrier, keeping the ingredient intact until it reaches the skin. Research on vitamin B12, for example, showed that encapsulation in liposomes significantly protected the vitamin from degradation caused by environmental factors and improper storage.
Second, bioavailability. Because liposomes can cross the skin barrier and release their contents in living tissue, a higher percentage of the active ingredient actually reaches the cells that need it. Without a delivery system, much of what you apply stays trapped on the surface and eventually washes or wears off.
Third, controlled release. Liposomes can be engineered to release their contents at a specific rate, which means your skin receives a steady supply of the active ingredient over hours rather than a single burst. This extends the product’s effectiveness and reduces the need for frequent reapplication.
Fourth, biocompatibility. Because phospholipids are structurally identical to the lipids already in your cell membranes, liposomes are well tolerated by the skin and far less likely to trigger irritation or adverse reactions compared to synthetic delivery vehicles.
How Liposomes Differ From Other Delivery Systems
Liposomes are not the only encapsulation technology in skincare, and the Milady curriculum touches on delivery systems as a broader category. Niosomes, for instance, are structurally similar to liposomes but use synthetic surfactants instead of phospholipids to form their bilayer. Transfersomes are a more flexible variation of liposomes, engineered to squeeze through even tighter spaces in the skin barrier. Micelles, by contrast, are single-layered spheres (not bilayered) that can only carry oil-soluble ingredients in their core, making them less versatile.
What sets liposomes apart is their dual-carrying capacity (both water-soluble and oil-soluble ingredients), their strong biocompatibility with human skin, and decades of research supporting their safety and effectiveness. They remain the most widely studied and commonly used vesicular delivery system in cosmetic formulations. No specific concentration limits or regulatory guidelines have been issued by the FDA or EMA for liposomes in topical skincare products, though regulatory agencies do classify them as complex formulations that require more stringent safety evaluation than conventional creams.
Liposomes on an Esthetics Exam
For the Milady exam specifically, the key points to remember are straightforward. Liposomes are a type of delivery system. They are closed, spherical structures made of a lipid bilayer. Their purpose is to encapsulate active ingredients and deliver them to targeted tissues within the epidermis. They improve penetration, protect unstable ingredients, and release their contents gradually. If you can connect those concepts, from structure to function to benefit, you have a solid understanding of what liposomes are and why they appear in professional skincare products.