Don't think of it as "causes me to relax", you're the one doing the relaxing. You already know how to do it without the pill too, just pretend you're taking it. And then pretend you're pretending. And then practice a couple of times until you can do it automatically and don't need to think about it anymore.
Very interesting decision from the one of the leading scientific publications to publish an article about Reiki therapy.
http://www.nature.com/news/consider-all-the-evidence-on-alternative-therapies-1.18547
[Edit: should be Nature publishes an article about alternative therapy]