Aging skin tends to wrinkle and sag thanks in large part to the waning of the skin-firming fibers known as collagen and elastin. There's no shortage of creams, serums and moisturizers that promise to erase lines and tighten skin. Anti-aging creams can't give the results of a face lift. A few products however can penetrate the skin and effectively diminish the signs of aging, notes the American Academy of Dermatology.

Alpha-lipoic acid is a very powerful antioxidant that helps prevent skin damage while reversing past damage, according to the Cleveland Clinic. Alpha-liopic acid is able to reach all parts of the cell because it is both water and oil soluble.

Alpha-lipoc acid can help soften fine lines and give skin a youthful glow. It also enhances the antioxidants contained in other vitamins like vitamin C .

Anti-aging creams that contain vitamin C or ascorbic acid may promote collagen production, according to the University of Maryland Medical Center (UMMC). Topical vitamin C products may help improve skin firmness, diminish wrinkles and help soften the skin.

Hyaluronic acid is sometimes found in ant-aging products that also contain vitamin C to help the product penetrate the skin, according to the Cleveland Clinic.

Hyaluronic acid is a naturally occurring substance that helps lubricate and cushion the skin and other tissues. As you age hyaluronic acid is gradually destroyed. Products that contain hyaluronic acid are generally used to soften wrinkles.

Copper peptides can help stimulate collagen, elastin and hyaluronic acid production, according to the Cleveland Clinic. Copper is a trace element contained in every cell. In topical products, it's mixed with tiny protein fragments known as peptides.

Copper peptides can help soften and tightening skin often in a more timely manner than other skin care products.

Prescription-only tretinoin, brand name Retin-A, is a derivative of vitamin A. Tretinoin is the only topical treatment approved by the FDA to reverse sun damage or photoaging, according to the UMMC.

Tretinoin can stimulate collagen production and reduce skin roughness, wrinkles and age spots. It can take several months to notice the effects of tretinoin.

Alpha and beta hydroxy acids exfoliate the skin and clear away the upper layer of old, dead skin, according to the MayoClinic.com. Products that contain glycolic and salicylic acid can encourage the growth of smooth, evenly-colored skin.