Hyaluronic Acid is a high-molecular polymer, it is widely present in living organisms.
Hyaluronic Acid could be divided into many different types according to different standards. For example, there are Single-phase Hyaluronic Acid and Biphasic Hyaluronic Acid; Cross-linked Hyaluronic Acid and Non-cross-linked Hyaluronic Acid; By molecular weight, it has Low Molecular Weight, Medium Molecular Weight and High Molecular Weight, etc.
What is the difference between single-phase hyaluronic acid and biphasic hyaluronic acid?
To answer this question, we have to know the concept of “phase”first.
Phase is the state of the object, like: gaseous, liquid, solid; For hyaluronic acid, of course, it refers to the specific state of hyaluronic acid: as the name implies, single-phase hyaluronic is hyaluronic acid in a single state, and biphasic hyaluronic acid is hyaluronic acid in two states.
So what is the so called “state”? We have to get some knowledge about the concept “cross-link” and the production of Hyaluronic Acid.
1. Whats is “ cross-link”?
Briefly, cross-link is to join hyaluronic acid molecules together to form a longer one.
2. The production of Hyaluronic Acid
Single-phase hyaluronic acid is made by grinding large pieces of hyaluronic acid gel into a smooth injectable gel without adding any liquid. It is completely cross-linked hyaluronic acid;
Biphasic hyaluronic acid is made by drying hyaluronic acid gel into granules through a screening method, and then mixing it with hyaluronic acid stoste to prepare a hyaluronic acid product; this product containing both cross-linked hyaluronic acid and free hyaluronic acid is called biphasic hyaluronic acid.
In a word: If there is only solid form, it is single-phase Hyaluronic Acid; If there are both liquid and solid form, it is Biphasic Hyaluronic Acid.
So, the single-phase Hyaluronic Acid or solid Hyaluronic Acid, is also called cross-linked Hyaluronic Acid. It is in a uniform gel shape, has high cohesion, and could be injected into the body evenly and continuously, this may effectively prevent hyaluronic acid from spreading or moving due to external forces, the stability is much higher.
The single-phase Hyaluronic Acid has the features like: High viscosity value, could be used for lifting, not easy to shift or spread; Excellent support, easy for injection and long-lasting for facial shaping; Generally, the shaping ability is stronger with the higher cross-linking degree;
The Biphasic Hyaluronic Acid or solid-liquid mixed Hyaluronic Acid is a product that contains both cross-linked Hyaluronic Acid and free Hyaluronic Acid. It has the features like: high elasticity, good ductility and easy spreading; generally, the shaping ability is better with the lager diameter of the particle.
The Single-phase Hyaluronic Acid itself is in the form of a uniform gel, like jelly;
While, Biphasic Hyaluronic Acid is hyaluronic acid after cross-linking, like sago particles, evenly distributed in free liquid hyaluronic acid, like sago with coconut milk;
The two types of Hyaluronic Acid have different advantages and applicability. So, t is hard to say which type is better or worse.