Dermal fillers are made up of a substance called hyaluronic acid. This occurs naturally in our skin. Therefore, it has a relatively low risk of allergic reaction. Hyaluronic acid binds 1,000 times it weight in water, therefore, gives a plumping effect.
Dermal fillers are mainly used to replace lost volume when we age. This means that the skin already had the same amount of volume under it, before we lost it with age, and even weight loss. Simply by replacing what was already under the skin will not cause the skin to sag, although, once the filler is metabolised over a period of time, the skin will go back to how it appeared before dermal filler. In the instance where dermal filler is used for beautification – younger patients who do not have any ageing, but just want fuller lips, or higher cheekbones, the amount used will not stretch the skin. 1ml of filler only takes up 1/5 of a teaspoon, so is a relatively small amount of volume. For example, 1ml is normally only used to inject both the top and the bottom lip at a time. This means only 1/10 of a teaspoon of volume is injected to the upper and 1/10 into the lower lip. Some lips might require a little more in the top than the bottom, to create symmetry. Dermal filler breaks down over a period of time, so the skins elasticity will adapt and go back to how it was prior to injection, anyway.