Collagen and its partner, the stable protein elastin, are fibers that
interlace purposefully. They create the combination of plasticity and
tautness that makes up normal skin. Sudden increases in growth or/and
weight caused by puberty, pregnancy, fat gain or muscle gain, and the
corresponding changes in hormone levels, wreak havoc upon skin where
the stretching is greatest. Collagen production gets disrupted.
Elastin looses its function