How do I know if DefenAge is working?

In the original studies results were documented with computerized imaging in 6 weeks. 
Skin dryness is normal at the beginning but subsides quickly. This occurs because the skin’s barrier is most likely damaged due to environmental exposure, stress, tobacco smoke, diet and ingredients in other skin care products. It may take up to 4 days to feel 24/7 Barrier Balance Cream’s deep moisture-repairing effects. This can be especially true if rich, creams were used previous to Defenage. These types of products artificially mask skin dryness rather than repair the damaged barrier that causes the skin to be dry, rough and uncomfortable. There is no need for these types of moisturizers when skin’s barrier is normal and healthy-acting. 24/7 Barrier Balance Cream returns the skin to feeling and acting normal in less than a week because it contains ‘smart’ barrier balancing ingredients and powerful surface antioxidants.

Hello,
The average skin cycle is approximately 6 weeks.  This can be slightly longer as we have more birthdays.  Because DefenAge works to stimulate stem cells, you should give the product a full 6 weeks to work.
Happy Skin,
Dr. Berens