There are 3 key reasons for this:
#1 When taken orally as a pill, most DHEA is eliminated by the “First-pass effect” of the liver. Basically, this means that the liver filters most of the effective DHEA out before it can do any good; and what does end up getting into the bloodstream is DHEA-S (DHEA sulfate) not free DHEA.
#2 DHEA-S is not the same as free DHEA. DHEA-S is not converted by the body into free DHEA. DHEA can be converted into DHEA-S, but not the other way around.
(Hammer, Fabian, Subtil s, Lux P, Maser-Gluth C, Stewart P, et al “No Evidence for Hepatic Conversion of Dehydroepiandrosterone (DHEA) Sulfate to DHEA: In Vivo and In Vitro Studies” Journal of Endocrinology and Metabolism. March 8 2005 pp 3600-3605) http://jcem.endojournals.org/content/90/6/3600.full.pdf
#3 Medical research shows the human body metabolizes most DHEA into various smaller more specific hormones in the skin (the dermis). The skin is where we use most of the DHEA we make. So Twist 25 DHEA cream actually provides exactly what the body produces naturally (bioidentical DHEA) where it can be utilized (the skin).
“In postmenopausal women, all estrogens and nearly all androgens are made locally in peripheral target tissues from the inactive adrenal steroid precursor dehydroepiandrosterone (DHEA). In adult men, approximated 50% of androgens are made locally.”
(Fernand Labrie, Alain Belanger, Rene Berube, et al. University of Toronto Medical School. “Metabolism of DHEA in postmenopausal women following percutaneous administration” The Journal of Steroid Biochemistry and Molecular Biology. Vol 103, Feb 2007. pp 178-88)
Source: Oncology and Molecular Endocrinology Research Center, Laval University Hospital Research Center, Quebec City, Canada. firstname.lastname@example.org)
DHEA must be used as a properly made bioidentical DHEA cream called Twist 25