People who use retinoids, commonly available as over-the-counter Retin-A creams or doctor prescribed tretinoin, typically start to see results after as little as three months. However, the greatest reduction of wrinkles is experienced between six and 12 months of continual use, according to WebMD.
Retinoids, first approved for use on wrinkles in 1970, are also known to minimize brown spots and reverse the effects of sun damage. They work by breaking down the top layer of skin and stimulating the growth of new blood vessels to increase the skin's production of collagen. The extra collagen increases the skin's elasticity and firmness. The cumulative effect, typically seen after 90 days, prevents wrinkles at the skin's deepest layers, where they are formed.
Tretinoin is generally considered to be more effective at preserving and increasing collagen levels in the skin when compared to non-prescription creams, because its strongest prescribed strength is 100 times more powerful than any store-bought brand.
Users apply a pea-sized amount of cream to cleansed skin at bedtime. The skin should be allowed to dry after cleansing for at least 20 to 30 minutes before the cream is applied. Retinoid creams lose effectiveness and irritate the skin when they are mixed with even a small amount of water.