The site varies from entry to entry; I think the good entries are fairly good by my standards, and I link them in my own nootropics page. The main author silverhydra and myself agree on many things and he does have a basic appreciation of the applicability to nootropics of the various statistical/meta points I emphasize. (I don't have their interest in fitness and weightlifting, and I'm not really keen on using affiliate links or selling guides, but those are small sins.)
My site, so obviously biased, but entire spectrum of health and wellness vouches for us: http://examine.com/testimonials/
Testimonials aren't very strong evidence, since they can be heavily filtered, which is why any third rate book or website can feature a list of impressive-looking testimonials even when 99% of people said "this is a pile of steaming crap, ignore it". A testimonial from gwern means much more to me then what a hundred cherry-picked PhDs say.
(That being said, it looks like a very good website, congrats)
It is very high. They have a ton of citations in the page for every supplement. For each health claim for each supplement they list an effect size and a level of evidence based on the citations. They call this the human effect matrix and an example for fish oil is here. Not all the pages are as extensive as fish oil, obviously, because it is one of the most-studied nutritional supplements available.
Edit: I see now that you are probably referring to their "Reference Guide" rather than the site itself. I have never read it, I was only commenting on the information available on the site.
TL;DR: Supplements are mostly a waste
Exceptions I am aware of:
Everything else that shows a benefit turns out to have cohort issues IME. In other words only deficient people show a benefit. B12 or Vitamin C are good examples. I've been through much of examine.com and haven't found anything else worthwhile supplementing. if anyone spots anything feel free to post it.
Thank you, some interesting studies to check out there.
Edit: after reviewing the literature I am running a 60 day trial.
TL;DR: Supplements are mostly a waste
I don't think this is a useful statement.
Instead I would say that the need for supplements is strongly individual.
You're young, live in the tropics, and work outside all day? Nah, you probably don't need vitamin D supplements. You're old, live beyond the Arctic circle and it's now winter? Yes, taking vitamin D supplements is probably a good idea for you.
Take a blood test and look. Do you need potassium? Maybe, maybe not. Do you need magnesium? Maybe, maybe not. Do you have glucose issues? What do you hormones look like? How's your thyroid?
Everyone is different. There is no good generic advice with regard to supplements. Look, test, figure out what your unique body needs now.
I think we have a different mental model of the sort of person who clicks on the link and investigates examine.com. My impression is that the average person with no particular health problems wants to know which supplements have the largest effect sizes, which doesn't exist all on one page on examine.com unfortunately.
Honestly, that is why the S-G Reference was created. It's to get to that info quickly and easily.
He's referring to Examine.com's "Supplement-Goals Reference Guide".
Apparently "quickly and easily" means you have to buy it, and they don't even tell you the price upfront.I̶t̶'̶s̶ ̶n̶o̶t̶ ̶e̶v̶e̶n̶ ̶c̶l̶e̶a̶r̶ ̶i̶f̶ ̶i̶t̶'̶s̶ ̶s̶o̶m̶e̶ ̶k̶i̶n̶d̶ ̶o̶f̶ ̶b̶o̶o̶k̶ ̶t̶h̶e̶y̶ ̶s̶h̶i̶p̶ ̶t̶o̶ ̶y̶o̶u̶ ̶o̶r̶ ̶i̶f̶ ̶i̶t̶'̶s̶ ̶o̶n̶l̶i̶n̶e̶ - okay, no, scratch that, it's a PDF.
Absolutely. Also of importance are zinc and vitamin K.
Still, what you've done is list supplements everyone should consider. The reality is that supplementation depends on contextual health goals, and that is where they shine.
A few simple examples:
Berberine and blood glucose Inositol and PCOS Bacopa and memory Rhodiola and fatigue (as James Miller mentioned) Feverfew and migraines
etc etc. Supplementation, when you apply it to contextual health goals, can be very powerful.
Examine.com's Guide to Supplements.