Collagen is a type of protein. Fibrous in nature, it connects and supports other bodily tissues, such as skin, bone, tendons, muscles, and cartilage. It also supports the internal organs and is even present in teeth. There are more than 25 types of collagens that naturally occur in the body.
Collagen is one of the most plentiful proteins present in the bodies of mammals, including humans. In fact, it makes up about 25 percent of the total amount of proteins in the body. Some people refer to collagen as the glue that holds the body together. Without it, the body would, quite literally, fall apart. Possessing great tensile strength, collagen functions in a manner that is very different from many other types of proteins. For example, it can be found both inside and outside of cells. Collagen fibers are important in contributing to the external structure of cells. However, they are present on the inside of some cells as well.
Collagen works hand-in-hand with elastin in supporting the body’s tissues. Basically, it gives body tissues form and provides firmness and strength; elastin gives the same body tissues much need flexibility. This combination of collagen and elastin is very important in many parts of the body, including, but not limited to, the lungs, bones, and tendons. Even the blood vessels rely on both collagen and elastin.
Often, collagen is discussed in relation to the skin. It works with keratin to provide the skin with strength, flexibility, and resilience. As people age, however, collagen degradation occurs, leading to wrinkles. As such, it is an important substance for those looking for ways to fight the visible effects of aging on the skin. Some skincare professionals actually advise people on ways to stimulate the production of collagen in skin cells.
In addition to being so important in the body, collagen also has many medical uses. It is used in some cosmetic surgery procedures and is sold as a supplement created for joint mobility. It is even used in treating and managing serious burns. For this purpose, it is used in creating man-made skin substitutes.
Since collagens are so important within the body, it stands to reason that collagen deficiencies can be problematic. In fact, there are some genetic diseases that are associated with collagen deficiencies. For example, osteogenesis imperfecta, commonly referred to as brittle bone disease, results from a significantly decreased level of collagen. It can also result from the presence of collagen that is of lower quality than normal.

What is Collagen?

Organ of sight
Hydrated collagen can be found in lenses. Together with polysaccharides it forms the optic disc.
Natural Collagen enhances visual acuity when applied on eye-lids.

Hair
Collagen constitutes the supporting material of hair follicles. Collagen pigment is identical with hair pigment. It restore beauty to the hair - gray hair gets darker, brows and eye lashes start growing again.

Bones
Classic example - like skin - of type I collagen occurrence in human body. Together with calcium and phosphorus salts type I collagen constitutes the bone building material. It forms 95% of bone matrix. It undergoes all physiological changes, life biological cycles, diseases, and diets.
Nerves and vessels
Collagen is a component of nerve fiber myelin sheath, spinal cord, brain meninges, and nerve cell basement membranes. Vessels - arterial, venous, lymphatic.

Alimentary tract
Type II and III collagen is the scaffold supporting stomach, intestine and esophagus parietal cells.

Collagen in menopause
The decrease of collagen turnover in women in perimenopausal period causes a number of diseases of the bone system and genitals. In urinary-genital system the disturbances of genital and urinary tracts trophiecs and statics are most common.

Discussing collagen deficit in women in this period of their lives, C. Falconer stresses that commonly used hormone replacement therapy results in the increase of hydrated type II and III collagen store in the urinary-genital system. Falconer has also shown that a number of dysfunctions, e.g. genital organ lowering, mucous membrane dryness, urinary incontinence, and inflammatory states, are caused by the change of collagen quantity and quality. The lack or small production volume of type II and III collagen by connective tissue cells cause the deficit of hydrated collagen in extracellular space. In such case the supply of estrogens results in a dramatic improvement.

Dosage
Collagen must be taken on an empty stomach, with water, at least 2 hours after a meal (3 hours after a heavy meal). It should be taken as one of the last things you do before retiring for the night. Daily dosage should be two capsules taken with a glass of water. The collagen has to pass through the stomach and into the intestine without being "damaged" (broken down) by stomach acid. This is why the stomach MUST be EMPTY. If it is broken down along with food, it is then no longer collagen and so becomes totally ineffective.

Possible Side-Effects / Precautions / Possible Interactions
Research Studies / References