How Long Will a Collagen Injection Last?

Collagen filler is a naturally-derived filler product - previous collagens were from bovine sources (cows), human sources (cadaver) and porcine sources (pig tendon). Not very glamorous sources, but collagen is a protein and thus far science has not been able to come up with a synthetic one for use in the skin.
Because they are non synthetic, they tend to break down very quickly. Most patients saw a 3 month duration - some a little more and others a little less. Recently Evolence was on the market for a brief period and was to have lasted 6 months or longer, but the economy hit it too hard to stay so for now, we only have the bovine and human collagens.
Because the newer hyaluronic gels such as Restylane and Juvederm last twice as long, they've pretty much taken the place of collagens for primary wrinkle filling and lip augmentation, but you can still get collagen if you desire.

Great question. Collagen has been replaced by a new generation of fillers for the lips. Collagen was offered for injections in the 1990s but had limited longevity and some allergic risk. They have been replaced by things like hyaluronic acid gels which are easier to inject, longer lasting, and without allergic risk. I would recommend Juvederm Ultraplus which is a smooth gel that I utilize to plump and shape the lips. These fillers are temporary and reversible.
I hope this helps.

Collagen was one of the first fillers on the market many years ago. They are not as popular today since they do not last long. Generally, collagen injections last around 3 months compared with Hyaluronic fillers like Restylane which typically last 5-7 months(or more).

Also, the Hyaluronic fillers (Restylane, Juvederm, Perlane) are more fluid like substances which tend to attract water to the tissues for a softer look. They are well tolerated and have minimal down time as far as recovery is concerned.