What this site is for
This is patient education about the lips, published by Chongqing West District Hospital, a tertiary general hospital in Jiulongpo District, Chongqing. It is an area guide rather than a procedure page: it answers which of several structures is producing your complaint, which options address that structure, and how to choose between them. The procedures themselves are described on the guides this site links to, and repeating them here would help nobody.
The distinction the site is built on
The lips are a functional organ and an aesthetic one, and the same anatomy serves both. Four findings produce the same complaint and are treated by means that have nothing in common: not enough tissue, a border that has flattened, skin that is too long above the lip, and a muscle holding the lip where you do not want it. Almost everyone arrives with those merged into one sentence, and naming the right one is most of the decision. Two people asking for fuller lips can therefore need opposite plans.
Why the two routes are given equal weight
An injectable adds material and can be dissolved; an operation removes or repositions tissue and cannot be undone. Neither is the default answer to a mouth, and neither is a smaller version of the other. Where the finding is tissue or border, the reversible route usually comes first and its ceiling is stated. Where the finding is a measurement only an operation changes, saying so is more useful than starting with an injectable and discovering the ceiling later.
What it deliberately does not do
It does not name products or brands, quote prices or dosages, or promise a result. It does not describe a lip as too thin or too full against a fashion, because proportion is read against your own lower face. It does not present an injectable as a way of shortening the upper lip or changing a bite, because it does neither, and it does not describe an operation that removes tissue as reversible, because it is not.
The limits of a website
Nothing here can tell you how much of your own lip is tissue and how much is position, whether a muscle is doing the work, or how long your philtrum actually is. Those answers come from someone measuring the lip at rest and while it is moving, which takes minutes in person and cannot be taken from a photograph. Use this site to arrive at an assessment with better questions, and treat any answer you receive here as general information rather than as advice about you.