People want to know how long it takes for products to work.  The time may vary depending on your skin issues and products that you use.

Peptides for example can take 28 days to see results. Sometimes you will see results sooner.  Once you start using peptides, the results will keep getting better and better. I personally would not be without them.  They make a big difference in the anti-aging process.

Most medical grade skin care lines ask you to use the products 30 days for results.   Many times you will see results immediately and it can also take longer for results. 
When you are using effective products with the proper ingredients, give them time to do their work.

Do not be looking at overnight miracles.  Improvement is slow and you will notice small improvements daily.  Start looking for compliments when someone tells you how good you look