If you have one and gel and other in cream then I would wait an hour before application between each just to be sure.
As you are a patient of DR C
His patients are instructed to take cream and gels as directed
Oral DHEA and vitamins should be discontinued 48 hours prior before urine collections. Apply them as directed.
I also have personal contact with the director of the lab as well because of being a health professional. We also use rhiens as well as follow the same protocol DR C has developed.
That will be 60 bucks LOL