I am a huge believer that Botox should be used to minimize wrinkle while still having movement....not completely eliminating it and looking frozen. With that said, if you are young and have minimal wrinkles you may be able to spread the 20 units to the 11's and the crow's feet. It would be a low dose to minimize future wrinkles. If you have established wrinkles, 20 units is quite low. The best thing to do is ask the person providing the units how much should be used in each area to get the result you want. I am not really sure how you can decide what to buy if you have not done it before. Perhaps consider a different location where they take the time to help you get the best results rather than just packaging it. What if you need 32 units? Gonna throw the rest out? Gonna use more than you need just to use it? Go somewhere that they customize it for you. You won't regret it.Dr Rodger ShorttOakville Plastic SurgeonAssistant Clinical Professor &Director of Cosmetic Surgery Training Program,McMaster UniversityOakville, Burlington, Georgetown, Milton, Mississauga, Hamilton, and Toronto.