Collagen is a fibrillar protein that conforms the conjunctive and connective 
tissues in the human body, essentially skin, joints, and bones. This molecule is 
one of the most abundant in many of the living organisms due to its connective 
role in biological structures. Due to its abundance, strength and its directly 
proportional relation with skin aging, collagen has gained great interest in the 
cosmetic industry. It has been established that the collagen fibers are damaged 
with the pass of time, losing thickness and strength which has been strongly 
related with skin aging phenomena [Colágeno para todo. 60 y más. 2016. 
http://www.revista60ymas.es/InterPresent1/groups/revistas/documents/binario/ses330informe.pdf.]. 
As a solution, the cosmetic industry incorporated collagen as an ingredient of 
different treatments to enhance the user youth and well-being, and some common 
presentations are creams, nutritional supplement for bone and cartilage 
regeneration, vascular and cardiac reconstruction, skin replacement, and 
augmentation of soft skin among others [J App Pharm Sci. 2015;5:123-127]. 
Nowadays, the biomolecule can be obtained by extraction from natural sources 
such as plants and animals or by recombinant protein production systems 
including yeast, bacteria, mammalian cells, insects or plants, or artificial 
fibrils that mimic collagen characteristics like the artificial polymer 
commercially named as KOD. Because of its increased use, its market size is 
valued over USD 6.63 billion by 2025 [Collagen Market By Source (Bovine, 
Porcine, Poultry, Marine), Product (Gelatin, Hydrolyzed Collagen), Application 
(Food & Beverages, Healthcare, Cosmetics), By Region, And Segment Forecasts, 
2014 - 2025. Grand View Research. 
http://www.grandviewresearch.com/industry-analysis/collagen-market. Published 
2017.]. Nevertheless, there has been little effort on identifying which collagen 
types are the most suitable for cosmetic purposes, for which the present review 
will try to enlighten in a general scope this unattended matter.