I tried to send this message earlier, but I received an automated reply from Meetup stating that my attachments were to large to pass through their system. My message follows without the attached research studies.
I've uploaded the files to our Meetup site and link them here:
Thanks for that link. I have no doubt that human skin can absorb many organic compounds, but I am skeptical as to how much caffeine one can absorb from a simple spray application. I don't know what they claim the caffeine concentration or dosage of the spray is, but I'd think that the solution would evaporate rather quickly and not leave much of an effect. Like the author in the article that you linked to, I think the Shower Shock caffeinated soap and Sprayable Energy are using caffeine in their product as a gimmick that has unproven results in these applications.
Surprisingly, to the credit of the makers of Sprayable Energy, I received a response regarding the testing of their product. I was sent a couple of documents (attached) providing research on caffeine permeation through the skin, but they did not provide me with test results of their own product. I sent another email asking if they have any results from any independent double-blinded placebo-controlled studies on the effectiveness of their product. Seeing as so many people on Indiegogo have helped exceed the projects funding goal of $15,000 (they've raised more than $35,000) due to a positive marketing narrative and lack of evidence, I think I might find a pink unicorn before I see a high-quality study. I'll let you know what their response is.
BTW: With these trendy marketing claims of caffeine, I was wondering, why not have caffeine in underwear? People, mostly, put fresh clean underwear on everyday. Who wouldn't want some caffeine goodness in their pants? Well, Google found me this
. It's not really for me though.