I'm Soviet-born, atheist, and very much a fact- and number-junkie. I have a POV that differs radically from the majority of the community here.
Natural supplements scare the hell out of me, for example, because for them to actually provide any noticeable non-placebo effect, they really have to be unlicensed herbal meds (FDA might not license and regulate herbs - but many other health ministries or supervising bodies in the rest of the world DO)... The creepy thing about herbal meds is that any simple herb has at least several hundred different potentially active ingredients, one or more of which address the problem you bought the pills to treat - but nothing except concrete research will guarantee that the other 99% of the potentially active phytochemicals don't interact with something else you're taking, complicate existing illnesses, or otherwise mess with you... And, since the American healthcare community largely ignores herbs as "harmless supplements", no one actually studies them at all, unless quite a few people are proven to have died from taking that specific herb (again, 90% of the time, chances are, no one is going to even bother doing an autopsy and figuring out what killed someone anyway, and if they are desperate enough to go with herbal meds, they definitely have some convenient-to-blame preexisting disease already!).
...in Russia (FOR ALL ITS FAULTS - which are legion!), for example, a bunch of stuff like certain vitamin or herbal supplements (multivitamins, ginko from respectable brands, etc.) are actually approved MEDICATIONS, with publicly available clinical tests and so on, while the entire unlicensed supplement market is based around the premise of "the government warns you that this stuff can be whatever the hell, and suggests you really think twice first" (local counterpart to the FDA only requires low toxicity test results on standard dosages to pass muster - it guarantees that if it's legal, then it ain't concentrated poison, but nothing more).
For something like garlic, yeah, I trust it cause I can feel the die-off Herxheimer's, but at the same time, I haven't seen anything about anyone ODing and dying from garlic on TV or anything like that. With stuff like Pau D'arco, my feeling is that it's about as strong as natamycin, making it an option for a treatment combo, though not as a first-line treatment... BUT, here, pharms are A LOT more accessible than good supplements, so maybe I just haven't gotten a hold of the good stuff. All I've been able to score was an american mix of herbs called "NOW FOODS Candida Clear", 180 caps (45 days of recommended dosage) for 50 bucks, and through some pretty complicated preorder channels at that... It certainly packed a kick, but I wouldn't say that it was anywhere near as strong as 200mg itraconazole and/or 300mg fluconazole (2 standard pills of either or both) per day.
Also, it might be that UNRESTRICTED access (prescriptions are never checked for non-psychoactives here) to nystatin @ 3cents per .5mil IU pill, natamycin @ 50 cents per 100mg pill, fluconazole @ 60 cents per 150mg pill, and itraconazole @ $1 per 100mg pill is skewing my perceptions, because that might make harsh and effective pharmaceutical protocols more available affordable to me than an herbal alternative would be to an american (who might be stuck paying $10 per pill for original diflucan fluconazole, nevermind that it is the exact same thing). Cuz, really, I buy all my meds at any of 4 pharmacies in under half a km walking distance from home, and the only hassling I've ever gotten from a pharmacist was for a strictly prescription-only muscle relaxant (just the once - and it's not like I'd EVER had a prescription for it, just a tip I heard about it online somewhere - and it's not like that kept me from buying it within 5 minutes from a competitor pharmacy, albeit for an extra $2 per 30-pill pack).