I've tried adding about 20mg Yohimbine HCL about an hour or two before taking clen around the 2 week mark. Besides shaking ridiculously, sweating like a pig, and breathing really weird for a couple hours after, I'd say it's a great idea. Take into consideration that if you build up to 200mcg at around 2 weeks, you will definitely want to lower the dose of Clen once you add something like Yohimbine or Ketotifen. I figured this out the hard way. :run: