The main ingredient is yohimbine, which acts on a different class of andrenoreceptor (alpha-receptors) than ephedrine. These are actually inhibitory to lyposis, so it works by blocking the receptors actions IIRC. Theoretically this should mean it should still have an effect despite your tolerance to ephedrine. I personally haven't tried yohimbine, but many mention ositive results from lipo-6.
I have found green tea extract a worthwhile supplement, especially while "cold-turkeying" from ECA. It seems to have both mild appetite suppressing and stimulating properties.