I tried like all there is in that field from natural to steroids..
750mg of tribulus terrestris is really not much.
if you feel like you have a test. trouble , consult a doc, my ex BF who was like you know , a fag, (feminine voice and all) , had blood test and was prescribed steroids. I also did the same.
if you want only natural products , well you have the testojack mix, the horny goat, Tongkat Ali , Maca, Muira Puama , epimedium..but DHEA also is very great it boost testosterone ( but I dunno what's your age so.. it wont do much if you are 20 ) . I like this product : http://eu.iherb.com/Mason-Vitamins-Horny-Goat-Weed-Plus-With-Maca-Extract-60-Capsules/50263 it really really makes your testosterone to the roof. you'd fuck a letter box 🙂
have a look here : http://eu.iherb.com/search?sug=testosterone&kw=testos&rank=1
But dont dream, all natural stuff wont do much compared to real medicine.
Taking caps of testosterone is of course the best ( no need of syringe and all it's light) but you need a prescription: it makes you as great as any porn actor (can even increase your dick size if you use a pump while under this medication everyday), and with work out it's great ( if you take also amino acids and proper diet).
If you are old ( 35-40 and up) than you can consult an anti aging doc to get somatropin ( it requires blood test of course: and the goal is to put all your hormonal levels back to where they where when you were 20) but be warned although great ( it makes you look 10 years younger , that's guarantee ( they are risks though) ), it costs a lot ! .
My doc who is specialized in anti-aging medicine, recommended me to buy on iherb.com I can tell you that's great there, you can find all you need at low cost for natural testosterone booster. ( If you plan to buy some stuff there ask me I'll give you a code to get special price on your order)
So In a word Tribulus terrestris alone… well... don't expect much.. still they say on the one I took to take up to 2 pills/day of 1g before meal ( http://eu.iherb.com/Now-Foods-Sports-Tribulus-1-000-mg-180-Tablets/15273) . With natural products you need to stack with other things like this one that is commonly use by any guy who want to increase test : http://eu.iherb.com/Now-Foods-TestoJack-200-60-Veggie-Caps/22554 . Now I dont clearly understand what is you goal.
is it to gain muscle or more about your mood? Coz about the mood they are lots of plants that can help but it's not about testosterone.
Ps: Im not affiliate with iherb, also I see you are from the Us so my links are for the european server of iherb you'll need to change your location on their site