There are several types of skin rejuvenation services to consider. Some provide immediate results, while others work slowly over time and may require multiple treatments. Skin rejuvenation usually involves a procedure that not only provides cosmetic improvements but also stimulates collagen and elastin so your skin has a tighter and more uplifted appearance. A newer skin rejuvenation treatment you might want to consider is stem cell therapy. Here's how the treatments rejuvenate your skin.