I've never had bloodwork done to know if it really boosts test or not, but I've used Tribulus (I particulary like Ultimate Nutrition's) on and off for probably about 20 years. A co-worker who was black asked me what I thought were good supps to take when he first started working out. I told him vanadyl, creatine, AAKG, tribulus, and protein was the only things I thought were worth a shit (vitamins and EFA's aside)
I explained that trib supposedly raised test, and that although I wasn't sure if that was true, I felt a bit stronger and slightly more aggressive in the gym when using 1500-2250mgs, and that if nothing else him and his wife would like it.
Now remember, I've said here often that I hate today's hip-hop....it's unavoidable to hear it though. I mention that, because a few weeks later he stopped by my cube, and thanked me for telling him about it. I asked what he noticed, and he said he did feel stronger in the gym but that he mostly liked the bedroom side-effect. I said "yeah, gets ya full mast and wanting to screw the Mrs. more right?" He laughed, and replied something like "hell yeah! Skeet, skeet, skeet like crazy" The only time I'd ever heard that word was in that one hip-hop song, so I asked wtf that meant? It was then that I learned that song was about shooting a load on a bitch. I guess I got bro-splained. I also did not know what "super man that ho" was about until he explained that as well.
If you're ok with walking away from natty status, then Coach's post is the way to go.
I've used Now and Met-Rx's versions as well, but I think Ultimate's are better since their capsules vs. tabs. Supposedly, Tribestan and Tribex are the best, but way too pricey for me.